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Teacher’s Guide

TM

PhotosynthesisGrades 5-12

PSTV

CREDITS

Program P roduc t ionSunburs t V i sua l Med ia

Teacher ’s Gu ideKr i s t i e Micha lowsk i , M.Ed .

P r i n t Mate r ia l Des ignLe igh A . Sh inn

© 2004 Sunburst Visual Media, a division of Global Video, LLCHawthorne, NY 10532

Approximate running time: 35 minutes

Photosynthesis

© Sunburst Visual Media, a division of Global Video, LLC Photosynthesis

TABLE OF CONTENTS

Guide Information ............................................05

Fast Facts ..........................................................08

Before Viewing Activities ..................................09

During Viewing Activities ..................................14

After Viewing Activities ....................................20

After Viewing Quizzes ......................................22

Additional Resources ........................................25

Answer Keys......................................................33

Script ................................................................47

5© Sunburst Visual Media, a division of Global Video, LLC Photosynthesis


ABOUT THIS GUIDEProviding students with visual media is an excellent way to take them out of the classroom and into the real world. Our programs offer real-world footage, dynamic graphics, engagingdramatizations, and first-person testimonials that keep students interested and help them visualize difficult concepts. More importantly, they reinforce critical learning objectives shaped by state and national educational standards. However, the learning doesn’t begin and end when the program does. You can make the learning experience even more effective by using the materials provided in this Teacher’s Guide.

Guide Information

This guide is divided into the following sections:

• Fast Facts are designed to give your students a quick overview of the information presented within the video.

• Before Viewing Activities help identify what students already know about the subject, what they are curious about, and what they hope to learn.

• During Viewing Activities may be used during viewing to enhance students’ understanding of the video.

• After Viewing Activities help students summarize and draw conclusionsfrom the information that was presented.

• After Viewing Quizzes test students’ retention of the information presented in the program and activity sheets.

• Additional Resources are designed to help you extend the information presented in the program into other areas of your curriculum.

• Answer Keys are provided for relevant activities or reproducible pages.

• Script content is provided in an unabridged version for future reference.

PROGRAM OVERVIEWPhotosynthesis provides a solid explanation of the process of photosynthesis and can be used as anintroduction or review of the process. The program is presented in a news-show format to presentkey concepts relating to photosynthesis.

The program includes:

Guide Information

Photosynthesis © Sunburst Visual Media, a division of Global Video, LLC6

Vocabulary and key concepts are shown in the program through “text boxes” for ease in notetaking. Ideas are stated visually and verbally to target different learning styles. Items arepresented in multiple styles to engage students’ interest.

These styles include:

Key concepts are also summarized in the conclusion to aid in comprehension.

• Vocabulary necessary to understand photosynthesis

• Contributors to the photosynthesis process

• Necessary components needed for photosynthesis to occur and how the process works

• Explanation of the chemical equation

• Explanation of the Calvin-Benson Cycle

• The importance of photosynthesis and how it provides the basis for all organic life on Earth.

• Visual diagrams

• Sports report

• “On-site” reporting

• Television commercial

• Music: “N’ Science”

• Poetry: “Science Poetry”

7

Guide Information

© Sunburst Visual Media, a division of Global Video, LLC Photosynthesis7

VIEWING OBJECT IVESAfter viewing the program and utilizing the activities provided in the Teacher’s Guide, students willbe able to:

• Understand and define key vocabulary words related to photosynthesis and use them appropriately when speaking or writing

• Identify the steps in the process of photosynthesis

• Identify the parts of a plant involved in photosynthesis

• Identify the parts of a chloroplast

• Identify the chemical equation of photosynthesis

• Identify the products involved in photosynthesis

• Identify the outcomes in the photosynthesis process

• Diagram and explain the ATP-ADP cycle

• Describe the photosynthesis process by which the Earth’s oxygen supply is replenished

• Describe how photosynthesis provides the basis for all organic life on Earth

• Describe how light initiates the chemical reactions of photosynthesis

• Describe how the Sun is the source of the Earth’s energy

• Describe how the Sun’s energy travels as photons of light energy

• Describe how the chemical reactions in plants are catalyzed by enzymes

• Describe the light reactions of photosynthesis

• Describe the dark reactions of photosynthesis

• List the reactants, products, and other requirements of photosynthesis

Fast Facts


• Carbon-based compounds are carbohydrates such as sugars and starches.

• Through photosynthesis, plants synthesize food using light energy.

• Photosynthesizing plants are at the heart of the food web.

• Plants use sunlight, water and carbon dioxide to make the food they need to grow.

* Photosynthesizing organisms cause the atmosphere to accumulate oxygen.

• Photosynthesis is the basis for our food and air.

• Photosynthesis helps maintain nature’s balance.

• All photosynthesizing plants are autotrophs.

• Organisms nourished by other organisms are called heterotrophs.

• Transpiration: releasing of water and oxygen from leaves.

• Meso = middle, Phyll = leaf

• The mesophyll is where most photosynthesizing takes place.

• Chloroplasts are the organelles of photosynthesis.

• ATP = adenosine triphosphate

• ATP production in the thylakoid membrane system is light dependent;

that is, it requires sunlight.

• Sugar assembly in the stroma is light independent; that is, it does not require light.

• Granum stacks help make ATP.

• ATP carries energy.

• Carotenoids absorb energy and transfer it to chlorophyll.

• It takes sunlight and chlorophyll to promote photosynthesis.

• Two light-dependent reactions: Cyclic and non-cyclic pathways.

• Calvin-Benson Cycle: sugar is synthesized with a light-independent reaction.

Photosynthesis Fast Facts

Name


Before ViewingActivity 1

Soak Up the Sun and Show What You Know!Fill in the chart below. In the S column, “SHOW” all of the facts you know about photosynthesis. In the U column, list at least three topics that you find “UNIQUE” about photosynthesis and would like to learn more about. After viewing the program and participating in various activities, list all the “NEW” things you havelearned about photosynthesis in the N column.

SShow what you know

UUnique topics

NNew items you learned

Name


1. : the mouth opening in the epidermis of the leaf

2. : the molecule that carries energy in the cells

3. : the middle of the leaf

4. : little stacks of disks that make up the thylakoid

membrane system

5. : the organelle that harvests light energy from light

6. : how sugar is synthesized with a

light-independent reaction

7. : the process in which food is synthesized using

light energy

8. : the semi-fluid interior of the chloroplast

9. : the release of water and oxygen from leaves

10. : produce their own food; self-nourishing

11. : made up of granum and the channels that

connect them; where ATP production takes place

12. : absorb energy and transfer it to chlorophyll

VocabularyBelow is a list of words related to photosynthesis. In each of the blanks that follow, write the wordfrom the list that best matches each definition.

PHOTOSYNTHESISSTOMAAUTOTROPHSTRANSPIRATIONMESOPHYLLTHYLAKOID MEMBRANE

GRANUMSTROMACAROTENOIDSCHLOROPLASTATPCALVIN-BENSON CYCLE


Name Before ViewingActivity 3

Hidden Message Word SearchFind each of the vocabulary words listed below in the puzzle. They may be across, up and down, backwards or diagonal. Circle or cross out each word. When you’re finished finding all of the words, look carefully at the first three rows of the puzzle. Write the letters that remain in these rows in the spaces below the puzzle. Make sure to copy them in the exact order that they appear. This will reveal the hidden message.

ATPAUTOTROPH

BACTERIACALVIN-BENSON

CARBONCAROTENOIDSCHLOROPLAST

CHLOROPHYLLGRANUM

HETEROTROPHMESOPHYLLPHOTONS

PHOTOSYNTHESISPROTISTS

STOMASTROMA

THYLAKOIDTRANSPIRATION

P H O T O N L S Y S N T H S L E S I S T

H E L P S O M L A I T N I L T A I N N S

A T U D R I E S Y B A S Y L A N C E V A

W N N I L T U R O H E H I Z J N M A N L

P T A O G A G R X H P M Q T E T G A O P

B K Q K X R G I T O U O A M O R T S B O

S P E A J I M N S N S G R C R R F X R R

N G H L M P Y E A A D F H O W A P J A O

O S K Y E S M R V U B Y S A L B A C C L

T I R H O N G N C A R O T E N H I D S H

O R S T O A D K C S T O M A Z H C S Z C

H A O R D R M T L A R M D H D P P C E D

P H Z H E T E R O T R O P H B O D P U I

P O Y I L R K Y R I A N W K D R I I P D

X A I T I Y P Z W Q V P M R H T Q E C K

S R O A P R G P C A R O T E N O I D S W

N O S N E B N I V L A C M I W T J D W W

U Y T S Y V G T L O S Z G T H U Z L Y U

I B K W D P E L W K X D N M D A M T K O

S S U B M P O H H B Z F L D J E E F R D

Message:


Name

Photosynthesis © Sunburst Visual Media, a division of Global Video, LLC

12


What Do You Think?Fill out the left side of the sheet before viewing the program. After you watch the program, fill outthe right side of the worksheet and check them against your original answers on the left.

Before Viewingtrue / false

After Viewingtrue / false

Photosynthesis is the process by which the Earth’soxygen supply is diminished

Plants contain specialized organelles called chloroplasts.

The stoma is the mouth-like opening of a leaf where the passage of carbon dioxide and oxygen are

allowed.

Carbon is an element present in all living matter.

Chlorophyll is not essential to photosynthesis.

The light reactions are also known as the Calvin-Benson cycle.

The stroma is where the light reactions of photosynthesis take place.

ATP is produced as a result of the build-up of hydrogen ions.

Photons are molecules that absorb light.

The thylakoid membranes are found in stacks called the mesophyll.

Name Before ViewingActivity 5

Vocabulary ScrambleUsing the word bank at the right, unscramble the words. Then, copy the letters in the numberedcells to the corresponding cells at the bottom to reveal the mystery word.

TAP

TASMO

ROTSAM

TYLPOSSIHO

HAPDN

PUORHTOAST

HLYLHOLPORC

TSDARCOINOE

CICCYL

NNO CYLCIC

MUGNAR

SOOLHPCLATR

LOSPYEMLH

POSTRNO

HOOTERHTREPS

TINTAPRISRAON

OYSMTESTOPHS

TILHG EEPNDENTD

LIGTH NDEEPIENTND

TIDLOKHYA MEABENRM

VICLAN NNBEOS LCCEY4

12

11

6

13

7

8

2

10

9

3

6

1

14

MYSTERY WORD:13 14121110987654321

CALVIN-BENSON CYCLEATP

THYLAKOID MEMBRANENADPHSTOMA

LIGHT DEPENDENTTRANSPIRATIONPHOTOSYSTEMS

AUTOTROPHSNON CYCLICMESOPHYLLGRANUMSTROMACYCLIC

LIGHT INDEPENDENTPHOTOLYSIS

CHLOROPHYLLPIGMENTS

HETEROTROPHSCAROTENOIDSCHLOROPLAST

PROTONS


Name


Just the Facts Please!Teacher note: This worksheet can be used solely as a note-taking device by using the FACT sectiononly, or it can be used in its entirety as a follow up activity after viewing the program.

This chart is designed to help you record important information while viewing the program. Record the facts in the “FACT” section and any questions or topics you do not understand in the“QUESTIONS” section.

QUESTIONS

COMMENTS

FACTS

During ViewingActivity 1

Name During ViewingActivity 2

1. “We’ve just discovered a news story that affects more different organisms

worldwide than almost any other.”

2. “The overall equation for photosynthesis tells us that water and carbon

dioxide, with the help of sunlight, is converted into oxygen, simple sugar,

and water.”

3. “Even in the sea, plants, photosynthesizing bacteria, and protists are

converting carbon dioxide and water into usable energy.”

4. “It sounds like we’re really dependent on photosynthesizing organisms

not just for food, but for the balance they create in nature.”

5. “So I have something in common with a mushroom? We’re

both heterotrophs!”

6. “Transpiration from plants is a major factor in the production of clouds

and therefore rainfall.”

7. “And the stoma is not only where water and oxygen exit the leaf, it is also

where carbon dioxide enters the leaf.”

8. “So what you’re saying is that photosynthesis has two parts. ATP

production in the thylakoid membrane system then sugars assembly

in the stroma.”

9. “Like most green plants, Chloro Cruncheez is loaded with the pigment

chlorophyll. This pigment absorbs violet, blue, and red light but transmits

green light, so it appears . . . green!”

Who Said That?While viewing the program make note of who says the phrases below. Choose the people from the list belowand fill in the name next to the phrase they said. Names can be used one or more times. The quotes are inchronological order.

Phil Chloro, weatherman Suzie Skyview, on-site reporter Kevin Leaf, announcerJohnny Spectrum, correspondent J.J. Carboni, sports reporter Laura Plast, announcerSpokesperson for Chloro Cruncheez


Name



Who Said That? (cont.)Phil Chloro, weatherman Suzie Skyview, on-site reporter Kevin Leaf, announcerJohnny Spectrum, correspondent J.J. Carboni, sports reporter Laura Plast, announcerSpokesperson for Chloro Cruncheez

10. “The first pathway is called the cyclic pathway and occurs in trees, weeds,

and other leafy plants.”

11. “I remember the ‘reactants’ in the photosynthesis equation were carbon

dioxide and water.”

12. “The ATP delivers energy, the NADPH delivers hydrogen and electrons,

and carbon dioxide provides the carbon and oxygen.”

13. “We also saw that within the photosynthetic cell, two types of reactions

occur. Light-dependent reactions proceed at an intricate membrane

system called the thylakoid membrane system.”

14. “And light-independent reactions proceed within the stroma.”

15. “And of course, J.J. Carboni’s personal favorite, the Calvin-Benson Cycle,

which is how sugar is synthesized with a light-independent reaction.”

Name

1. What are two carbon-based compounds?

2. What two items do autotrophs take from the environment to produce their food?

3. What are the two items that are released during transpiration from leaves?

4. What are the two membranes of the system?

5. What are the two stages of photosynthesis?

6. What are the two parts of photosynthesis?

7. What are two characteristics of chlorophyll?

8. During what two seasons is chlorophyll the predominant pigment in a leaf?

9. During what two seasons are carotenoids the predominant pigment in a leaf?

10. What are the two light-independent pathways called where sunlight causes electrons to move?

11. What are the two important molecules that are formed in light-dependent reactions?

12. What two components does photosynthesis use in its process to synthesize food?

What is the Magic Number?Many factors in photosynthesis contain two important parts. Fill in the blanks with your answers.

a. b.

a. b.

a. b.

a. b.

a. b.

a. b.

a. b.

a. b.

a. b.

a. b.

a. b.

a.

b.



Name


Label the LeafBelow is a diagram of a cross-section of a leaf. Label the diagram with the words in the box.

{

EPIDERMIS: outermost layer of the leaf. Waterproof coating that helps prevent water loss.

TRANSPIRATION: the process where water and oxygen get released from the leaves.

STOMA: microscopic opening in the epidermis where water and oxygen exit the leaf and carbon dioxide enters the leaf.

MESOPHYLL: where the stoma runs through the middle of the leaf.CHLOROPLASTS: organelles found in photosynthesizing plants.STROMA: semi-fluid interior of the chloroplast.


Name

Describe how the components are involved in photosynthesis.

State why the chemical equation is important to us.

Understanding the ChemicalEquation and Its ComponentsWrite the chemical equation for photosynthesis. Label which components are the reactants andwhich are the products.



Name


1. Draw a diagram of the cyclic pathway. Describe what is happening.

2. Draw a diagram of the non-cyclic pathway. Describe what is happening.

Light Dependent Reactions:Cyclic and Non-cyclic Pathways

After Viewing Activity 1

Name After Viewing Activity 2

Compare and ContrastUsing the Venn diagram below, compare and contrast the cyclic and non-cyclic pathways.

CYCL

ICPA

THW

AY NON-CYCLICPA

THW

AY

CYCLICAND

NON-CYCLIC PATHWAYS


Name


After ViewingQuiz 1

Vocabulary QuizFill in the blanks with the appropriate words from the vocabulary list.

PHOTONS - (n) packets of light energyCHLOROPLAST - (n) plant organelle where photosynthesis takes placeSTOMA - (n) mouth-like opening of a leaf, allowing passage of carbon

dioxide and oxygenXYLEM - (n) part of plant vein that carries water from root systemPHLOEM - (n) part of plant vein that carries food to the rest of the plantTHYLAKOID - (n) membrane where light reactions of photosynthesis are

carried outGRANUM - (n) stacks of thylakoid membranesSTROMA - (n) fluid that surrounds the thylakoid and where the dark

reactions occurCARBON - (n) element present in all living matterCHLOROPHYLL - (n) a green pigment essential to photosynthesis

1. After sucrose is manufactured in the leaf, it is carried via the

to feed the rest of the plant.

2. You can find the element in diamonds, coal, and wood.

3. A plant can lose a lot of water during a hot day, which is why each

closes during the hottest part of the day and closes again in the cooler evening.

4. absorbs most of the colors of light waves, except the green,

which bounces back off.

5. The thylakoid membranes are found in stacks called .

6. Water travels from the ground up through the plant’s stem through

the .

7. The light reactions take place inside the chloroplast within

the membrane.

8. The organelle that harvests light energy is the .

9. The is the watery matrix where the dark reactions

of photosynthesis take place.

10. originate on the Sun’s surface and travel to Earth in waves.

Name

1. _____ Which of the following is the chemical equation representing photosynthesis?a. ADP-3 + pi-2 + H + H2Ob. ATP-4 + H2Oc. 6CO2 + 6H2O C6H12O6 + 6O2 + 6H2Od. ADP + 6H2O C6H12O6 + 6H2O

2. _____ What are the two life sustaining byproducts of photosynthesis?a. sunlight and oxygenb. carbon dioxide and waterc. water and oxygend. oxygen and sugar

3. _____ What are the openings found on the underside of the leaf called?a. stromab. stomatac. chloroplastd. mesophyll

4. _____ Which of the following is the substance that allows photosynthesis to occur?a. sucroseb. chlorophyllc. lactosed. all of the above

5. _____ The sugar assembly takes place in the ________________.a. stromab. granumc. mesophylld. all of the above

6. _____ Where do the light reactions of photosynthesis take place?a. the inner membrane of the chloroplastb. the thylakoid membranec. the Calvin-Benson cycled. the electron of NADPH

Photosynthesis QuizWrite the letter of the best answer in the space provided, fill in the blank with the best answer, orwrite true or false for each statement.

After ViewingQuiz 2


Name


After ViewingQuiz 2

Photosynthesis Quiz (cont.)7. _____ During what two seasons is chlorophyll the predominant pigment in a leaf?

a. summer and fallb. fall and winterc. winter and springd. spring and summer

8. What two items do autotrophs take from the environment to produce their food?a. ___________________________________________________________________b. ___________________________________________________________________

9. What are the two characteristics of chlorophyll?a. ___________________________________________________________________b. ___________________________________________________________________

10. What are the two membranes of the stroma?a. ___________________________________________________________________b. ___________________________________________________________________

11. __________ True or False? Thylakoid membranes are found in stacks called mesophyll.

12. __________ True or False? ATP is produced as a result of the build-up of hydrogen ions.

13. __________ True or False? The light reactions are also known as the Calvin-Benson cycle.

14. __________ True or False? Light-dependent reactions occur at an intricate membrane system called the thylakoid membrane system.

15. __________ True or False? The mesophyll is where most of the photosynthesizing in a plant takes place.


25

Interdisciplinary Ideas

Reading and Writing:

Writing:Have students think of what their world would be like without photosynthesis. Have them write a science fiction story using the vocabulary words to strengthen theircomprehension and their story concept. Encourage your students to be imaginative. State that theywill need to show how important photosynthesis is to our world.

Writing:Have students pretend they are electrons in either the cyclic or non-cyclic pathway. Describe theirjourney and what happens to them at the end. What did they need on their journey to begin? Whydid they take one pathway over another? Diagrams are encouraged for visual learners.

Writing:Have students imagine far into the future. They are suppliers of nursery grown plants to the public.For some unknown reason, their plants are not growing and producing like usual. Their sales aredown. They need to know why. Have students discuss in small groups possible causes of theproblem and possible solutions to combat the problem.

Writing:Have students write how photosynthesis keeps nature’s balance and why this is important to them.

Read and Discuss:Have students choose a book from the suggested reading list or website from the photosynthesiswebsite list. Form small groups of students based on choice. Students should make a list of themajor points outlined in the book or website. Then discuss their findings. Share with other groupshow it supports their learning about photosynthesis.

AdditonalResources



Art, Music, and Technology:

Art:Have students create their own artwork illustrating the structure of the leaf, the structure of achloroplast, and the process of photosynthesis and its impact on life on Earth. Any medium is fine.

Art:Have students create the packaging for their own brand of cereal that promotes chlorophyll’simportance. Use a recycled cereal box wrapped in paper. Students will illustrate the front cover,create a game on the back, and include ingredients and recipes on the sides of their boxes.

Technology/Art:Have students use a drawing software program, like Inspiration, to create their interpretation of thecyclic pathway and the non-cyclic pathway. Have them label and show the motion of their model.

Technology/Art:Students can create a slide show about the process of photosynthesis. Each student or group ofstudents can research a specific part of the photosynthesis process. Then, help them transfer theirinformation to a slide show and sequence the slides in a logical order for final viewing. This is anexcellent method to review before the quiz.

Music:The program contained the music group “N’ Science” singing about photosynthesis. Have studentswrite their own lyrics dealing with photosynthesis. This could be done as a group activity. Then,have your students vote on the best song based on criteria you brainstormed with them ahead oftime. The criteria could include: scientific accuracy, most vocabulary words used, and best rhyming.

Poetry:Have students write a poem about any part of photosynthesis.

AdditionalResources

27


Science:

A Teacher’s Video Kit: Plant Pigments and Photosynthesis Lab Investigation KitMasked by green chlorophyll in the summer, the abundance of pigments in plant leaves becomesnoticeable each fall. Various pigment combinations lead to the changing colors of the leaves in thefall. These plant pigments can be separated using a technique called paper chromatography.Through this process, the pigments migrate on a special paper, with each pigment’s migration ratedependent upon its solubility.Available at: http://www.teachersvideo.com

Transpiration ExperimentShows how the hydrologic cycle works. Students will better understand the role of transpiration andits importance in our environment.http://yn.la.ca.us/cec/cecsci/cecsci.74.txt

Photosynthesis and TranspirationStudents will be able to see the effect of light on plants through this experiment. Will help studentsunderstand the Sun’s part in the photosynthesis process.http://yn.la.ca.us/cec/cecsci/cecsci.31.txt

Three Phases of PhotosynthesisThis experiment demonstrates the three processes of photosynthesis: respiration, the interactionbetween ADP and ATP, and the process of energy conservation.http://www.iit.edu/~smile/bi9641.html

Water Loss in PlantsExperiment in transpiration. Students research transpiration and make a hypothesis. Experiment isconducted and data recorded. Students then draw conclusions based on their data.http://www.lessonplanspage.com/ScienceExDoPlantsLoseWaterThroughLeavesMO68.htm

Lights Out: The Effect of Light on ChlorophyllStudents do an experiment to see if plants need light to be green. Will have a better understanding ofchlorophyll.http://www.lessonplanspage.com/ScienceExDoPlantsNeedSunToBeGreenMO68.htm

AdditionalReousrces



Interdisciplinary IdeasLeafy GreenThis experiment ties in with the “lights out” experiment. Students will see that green is not the only color apparent in leaves.http://www.lessonplanspage.com/ScienceExIsGreenOnlyColorInLeafMO68.htm

Math:Have your students find the mean, median, mode and range for the data collected in theexperiments above. Then, have them use the information to create line graphs, bar charts, or piecharts, and present their findings to the class.

Projects:News Show:Have students “produce” their own news show.Steps for students:• Decide on “jobs” necessary to run a production. They will need researchers, writers,

artists, news anchors, on-site reporters and producers.• Brainstorm ideas to include in their script writing based on photosynthesis.• Decide who will do what.• Gather resources. Besides the information that will be included in the show, they

will need props, scenery, video equipment (optional), etc.• Hold meetings regularly to regroup and see if there are any problems that have

arisen and to check the progress of each segment.

This type of project-based learning will help students improve their communications skills with each other, work on problem solving strategies, and engage their creativity. This ideaincorporates the many different talents of individual students. This will be most successful if it is agreat collaborative project that includes your school’s Media Specialist and/or TechnologyCoordinator. One can incorporate technology by having the diagrams “drawn” into a file. TheMedia Specialist can provide resources for further research and video cameras for the taping. SeeScript Template on page 41.

Research:Have students choose a topic from the “SUN” chart in the Before Viewing section. One could alsofind a topic during the viewing of the program.

Web Quest Treasure Hunt:Using the websites listed in this book, create a web quest treasure hunt where they have to findanswers to questions you give them or information based on a list of clues. Try to have the answersor clues pertain to different websites so they are able to view a variety of resources. This is a greatway to incorporate technology into the curriculum and meet technology standards.

AdditionalResources

29


Photosynthesis Jeopardy:The Questions/Facts Organizer the students used during the program and the “SUN” chart theycompleted before the program can each be used to help them create Photosynthesis Jeopardyanswers. The class can form two teams. You will need one person for the “host,” one judge, and a scorekeeper. This is a fun way to review before taking the quiz and to instill the concept ofphotosynthesis.

Technology/Science:Have students perform an experiment of seed-to-plant and photosynthesis. Take digital pictures.Have pictures in order to do a short video on the process. Can include additional slide of captionsor voice over.

AdditionalResources



AdditonalResourcesNews Show Script Template

Use this script template to help your students write their own news show. Use the left side of thetemplate for what is going on “back stage,” when to change scenery, go to a different “shot,” orfade the lighting. Use the right side for the actual script. State who is talking and what they aregoing to say. Please see the example below.

Example:

Show the newsroom getting ready for this show.

Have camera on news desk and news anchors.

Cue when ready.

Announcer:Good morning.

It is time for the local news.

31

Suggested Reading ListAsimov, Isaac. How Did We Find Out About Photosynthesis? Walker & Company

Library, 1989.States the discoveries that led to our understanding of photosynthesis. Discusses how the process isimportant in our daily lives and what factors threaten its role in balancing the environment.

Dalgleish, Sharon. Cleaning the Air. Chelsea House, 2003.Informative book about the future of our air. Includes the power of photosynthesis and the cyclingof carbon.

Hall, David Oakley. Photosynthesis. Cambridge University Press, 1999.Describes the process of photosynthesis with text, illustrations and colored plates.

Ross, Bill. Straight from the Bear’s Mouth: The Story of Photosynthesis. Simon & Schuster, 1995.Color illustrations and text describe the process of photosynthesis. Contains glossary and index.

Silverstein, Alvin. Photosynthesis. Twenty-First Century Books, 1998.Explains photosynthesis and related topics such as respiration, the carbon cycle, acid rain, and thegreenhouse effect. Explains the significance of the photosynthesis process.

Sneedden, Robert. Plants & Fungi: Multicelled Life. Heinemann Library, 2003.Illustrated look at how cells combine to form plants and fungi. Includes information on how plantsperform photosynthesis and the different ways they reproduce.

Staub, Frank J. Photosynthesis. Creative Education, 2004.Discusses the process of photosynthesis and has a complete index.

AdditonalResources



Internet SitesArizona State University: What is PhotosynthesisContains links to various articles and lesson ideas on photosynthesis.http://photoscience.la.asu.edu/photosyn/education/learn.html

Ask A Mad ScientistClick on “Search Archives” and type photosynthesis when asked for a keyword. Many questions on thesubject are in the archives. The site provides interesting and informative answers and different ideas forstudents to ponder.http://www.madsci.org/submit.html

FT Exploring: Science and TechnologyThis excellent site provides the basics of photosynthesis using key terms with links, photographs, and diagrams.Encourage students to use the other photosynthesis and energy pages listed on the left.http://www.ftexploring.com/photosyn/photosynth.html

Illuminating PhotosynthesisThis simple, interactive Flash demonstration of photosynthesis is great for visual learners, and has three“puzzlers” at the end for students to answer. The site emphasizes the chemical equation. Users will needFlash, but the site also has a non-Flash version to view.http://www.pbs.org/wgbh/nova/methuselah/photosynthesis.html#

Introduction to PhotosynthesisThis site starts with the origins of photosynthesis and ends with a diagram of the Calvin-Benson Cycle. It hasdetailed information on light and dark reactions as well as cyclic and non-cyclic pathways. Start on the linkedpage and click “next” for more information.http://www.mit.edu:8001/afs/athena/course/other/esgbio/www/ps/intro.html

Online Biology BookMany photosynthesis vocabulary words are included on this site which links to a glossary. The Calvin-BensonCycle is also diagrammed. The site includes great diagrams, links about photosynthesis, and review questions.http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPS.html

Origin of the Organic SoupThis site contains a good description of the plant structures involved in photosynthesis. It alsoincludes information on the products of photosynthesis. Diagrams and photos.http://www.bio.umass.edu/biology/conn.river/photosyn.htm

PhotosynthesisThis site has a great description of the process of photosynthesis and its importance. The siteincludes the steps and products of the process. The site does not provide visuals, but the process isclearly defined.http://scidiv.bcc.ctc.edu/rkr/Botany110/lectures/Photo.html

AdditionalResources


Answer Key - Before Viewing Activity 2

1. : the mouth opening in the epidermis of the leaf

2. : the molecule that carries energy in the cells

3. : the middle of the leaf

4. : little stacks of disks that make up the thylakoid

membrane system

5. : the organelle that harvests light energy from light

6. : how sugar is synthesized with a

light-independent reaction

7. : the process in which food is synthesized using

light energy

8. : the semi-fluid interior of the chloroplast

9. : the release of water and oxygen from leaves

10. : produce their own food; self-nourishing

11. : made up of granum and the channels that

connect them; where ATP production takes place

12. : absorb energy and transfer it to chlorophyll

Vocabulary Below is a list of words related to photosynthesis. In each of the blanks that follow, write the wordfrom the list that best matches each definition.

PHOTOSYNTHESISSTOMAAUTOTROPHSTRANSPIRATIONMESOPHYLLTHYLAKOID MEMBRANE

GRANUMSTROMACAROTENOIDSCHLOROPLASTATPCALVIN-BENSON CYCLE

STOMA

ATP

MESOPHYLL

GRANUM

CHLOROPLAST

CALVIN-BENSON CYCLE

PHOTOSYNTHESIS

STROMA

TRANSPIRATION

AUTOTROPHS

THYLAKOID MEMBRANE

CAROTENOIDS



Hidden Message Word SearchFind each of the vocabulary words listed below in the puzzle. They may be across, up and down, backwardsor diagonal. Circle or cross out each word. When you’re finished finding all of the words, look carefully atthe first three rows of the puzzle. Write the letters that remain in these rows in the spaces below the puzzle.Make sure to copy them in the exact order that they appear. This will reveal the hidden message.

ATPAUTOTROPH

BACTERIACALVIN-BENSON

CARBONCAROTENOIDSCHLOROPLAST

CHLOROPHYLLGRANUM

HETEROTROPHMESOPHYLLPHOTONS

PHOTOSYNTHESISPROTISTS

STOMASTROMA

THYLAKOIDTRANSPIRATION

P H O T O N L S Y S N T H S L E S I S T

H E L P S O M L A I T N I L T A I N N S

A T U D R I E S Y B A S Y L A N C E V A

W N N I L T U R O H E H I Z J N M A N L

P T A O G A G R X H P M Q T E T G A O P

B K Q K X R G I T O U O A M O R T S B O

S P E A J I M N S N S G R C R R F X R R

N G H L M P Y E A A D F H O W A P J A O

O S K Y E S M R V U B Y S A L B A C C L

T I R H O N G N C A R O T E N H I D S H

O R S T O A D K C S T O M A Z H C S Z C

H A O R D R M T L A R M D H D P P C E D

P H Z H E T E R O T R O P H B O D P U I

P O Y I L R K Y R I A N W K D R I I P D

X A I T I Y P Z W Q V P M R H T Q E C K

S R O A P R G P C A R O T E N O I D S W

N O S N E B N I V L A C M I W T J D W W

U Y T S Y V G T L O S Z G T H U Z L Y U

I B K W D P E L W K X D N M D A M T K O

S S U B M P O H H B Z F L D J E E F R D

Message: P H O T O S Y

B A L A N C EN A T U R E S

N

M A I N T A I N

T H E S I S H E L P S



What Do You Think?Fill out the left side of the sheet before viewing the program. After you watch the program, fill out the right side of the worksheet and check them against your original answers on the left.

Before Viewingtrue / false

After Viewingtrue / false

Photosynthesis is the process by which the Earth’soxygen supply is diminished

Plants contain specialized organelles called chloroplasts.

The stoma is the mouth-like opening of a leaf where the passage of carbon dioxide and oxygen are

allowed.

Carbon is an element present in all living matter.

Chlorophyll is not essential to photosynthesis.

The light reactions are also known as the Calvin-Benson cycle.

The stroma is where the light reactions of photosynthesis take place.

ATP is produced as a result of the build-up of hydrogen ions.

Photons are molecules that absorb light.

The thylakoid membranes are found in stacks called the mesophyll.



Vocabulary ScrambleUsing the word bank at the right, unscramble the words. Then, copy the letters in the numbered cells to thecorresponding cells at the bottom to reveal the mystery word.

TAP

TASMO

ROTSAM

TYLPOSSIHO

HAPDN

PUORHTOAST

HLYLHOLPORC

TSDARCOINOE

CICCYL

NNO CYLCIC

MUGNAR

SOOLHPCLATR

LOSPYEMLH

POSTRNO

HOOTERHTREPS

TINTAPRISRAON

OYSMTESTOPHS

TILHG EEPNDENTD

LIGTH NDEEPIENTND

TIDLOKHYA MEABENRM

VICLAN NNBEOS LCCEY

A T P

N O N

T H Y L A

S T O M A

N A D P H

C Y C L E

L I G H T

K

S T R O M A

C A L V I N B E N S O N

C Y C L I C

G R A N U M

C Y C L I C

O I D

D E P E N D E N T

L I G H T I N D E P E N D E N

A U T O T R O P H S

P H O T O L Y S I S

T

C H L O R O P H Y L L

C A R O T E N O I D S

C H L O R O P L A

M E S O P H Y

P R O T O N S

L L

S T

H E T E R O T R O P H S

P H O T O S Y S T E M S

T R A N S P I R A T I O N

P H O T O S Y N T H E S I

M E M B R A N E4

12

11

6

13

7

8

2

10

9

3

6

1

14

MYSTERY WORD:13

S14121110987654321

CALVIN-BENSON CYCLEATP

THYLAKOID MEMBRANENADPHSTOMA

LIGHT DEPENDENTTRANSPIRATIONPHOTOSYSTEMS

AUTOTROPHSNON CYCLICMESOPHYLLGRANUMSTROMACYCLIC

LIGHT INDEPENDENTPHOTOLYSIS

CHLOROPHYLLPIGMENTS

HETEROTROPHSCAROTENOIDSCHLOROPLAST

PROTONS


Answer Key - During Viewing Activity 2

1. “We’ve just discovered a news story that affects more different organisms

worldwide than almost any other.”

2. “The overall equation for photosynthesis tells us that water and carbon

dioxide, with the help of sunlight, is converted into oxygen, simple sugar,

and water.”

3. “Even in the sea, plants, photosynthesizing bacteria, and protists are

converting carbon dioxide and water into usable energy.”

4. “It sounds like we’re really dependent on photosynthesizing organisms

not just for food, but for the balance they create in nature.”

5. “So I have something in common with a mushroom? We’re

both heterotrophs!”

6. “Transpiration from plants is a major factor in the production of clouds

and therefore rainfall.”

7. “And the stoma is not only where water and oxygen exit the leaf, it is also

where carbon dioxide enters the leaf.”

8. “So what you’re saying is that photosynthesis has two parts. ATP

production in the thylakoid membrane system then sugars assembly

in the stroma.”

9. “Like most green plants, Chloro Cruncheez is loaded with the pigment

chlorophyll. This pigment absorbs violet, blue, and red light but transmits

green light, so it appears . . . green!”

Who Said That?While viewing the program make note of who says the phrases below. Choose the people from the list belowand fill in the name next to the phrase they said. Names can be used one or more times. The quotes are inchronological order.

Phil Chloro, weatherman Suzie Skyview, on-site reporter Kevin Leaf, announcerJohnny Spectrum, corresp. J.J. Carboni, sports reporter Laura Plast, announcerSpokesperson for Chloro Cruncheez

LAURA

KEVIN

PHIL

LAURA

LAURA

SUZIE

SUZIE

KEVIN

SPOKESPERSON



Who Said That? (cont.)

10. “The first pathway is called the cyclic pathway and occurs in trees, weeds,

and other leafy plants.”

11. “I remember the ‘reactants’ in the photosynthesis equation were carbon

dioxide and water.”

12. “The ATP delivers energy, the NADPH delivers hydrogen and electrons,

and carbon dioxide provides the carbon and oxygen.”

13. “We also saw that within the photosynthetic cell, two types of reactions

occur. Light-dependent reactions proceed at an intricate membrane

system called the thylakoid membrane system.”

14. “And light-independent reactions proceed within the stroma.”

15. “And of course, J.J. Carboni’s personal favorite, the Calvin-Benson Cycle,

which is how sugar is synthesized with a light-independent reaction.”

JOHNNY

LAURA

JJ

KEVIN

LAURA

LAURA

Phil Chloro, weatherman Suzie Skyview, on-site reporter Kevin Leaf, announcerJohnny Spectrum, corresp. J.J. Carboni, sports reporter Laura Plast, announcerSpokesperson for Chloro Cruncheez



1. What are two carbon-based compounds?


3. What are the two items that are released during transpiration from leaves?

4. What are the two membranes of the system?

5. What are the two stages of photosynthesis?

6. What are the two parts of photosynthesis?

7. What are two characteristics of chlorophyll?

8. During what two seasons is chlorophyll the predominant pigment in a leaf?

9. During what two seasons are carotenoids the predominant pigment in a leaf?

10. What are the two light-independent pathways called where sunlight causes electrons to move?

11. What are the two important molecules that are formed in light-dependent reactions?

12. What two components does photosynthesis use in its process to synthesize food?

What is the Magic Number?Many factors in photosynthesis contain two important parts. Fill in the blanks with your answers.

a. SUGARS b. SALTS

a. WATER b. OXYGEN

a. INNER MEMBRANE b. OUTER MEMBRANE

a. LIGHT-DEPENDENT STAGE b. LIGHT-INDEPENDENT STAGE

a. SUMMER b. SPRING

a. FALL b. WINTER

a. CYCLIC PATHWAY b. NON-CYCLIC PATHWAY

a. ATP b. NADHP

a. LIGHT b. ENERGY

a. CARBON b. ENERGY

a. MAIN PIGMENT FOUND IN PHOTOSYNTHESIS ORGANISMS

b. IT IS GREEN SINCE IT TRANSMITS GREEN LIGHT

a. ATP PRODUCTION IN THE THYLAKOID MEMBRANE SYSTEM

b. SUGARS ASSEMBLY IN THE STOMA



Describe how the components are involved in photosynthesis.

State why the chemical equation is important to us.

Understanding the ChemicalEquation and Its ComponentsWrite the chemical equation for photosynthesis. Label which components are the reactants andwhich are the products.

12H2O 6CO2 6O2 C6H12O6 6H2O

WATER

REACTANTS

CARBONDIOXIDE OXYGEN

PRODUCTS

GLUCOSE WATER

Water and carbon dioxide with the help of sunlight is converted into oxygen, simplesugars, and water. The water and carbon dioxide on the left side of the equation areknown as the reactants (before the reaction). The oxygen, glucose, and water on theright side of the equation are known as the products (after the reaction). It takessunlight and chlorophyll to promote photosynthesis.

The chemical equation is important to us because we rely on photosynthesis to survive. It provides us with food to eat and our air to breathe.

LIGHTENERGY



Label the LeafBelow is a diagram of a cross-section of a leaf. Label the diagram with the words in the box.

{

EPIDERMIS: outermost layer of the leaf. Waterproof coating that helps prevent water loss.

TRANSPIRATION: the process where water and oxygen get released from the leaves.

STOMA: microscopic opening in the epidermis where water and oxygen exit the leaf and carbon dioxide enters the leaf.

MESOPHYLL: where the stoma runs through the middle of the leaf.CHLOROPLASTS: organelles found in photosynthesizing plants.STROMA: semi-fluid interior of the chloroplast.

STROMA

CHLOROPLAST

EPIDERMIS

MESOPHYLL

STOMA

TRANSPIRATION


1. Draw a diagram of the cyclic pathway. Describe what is happening.

2. Draw a diagram of the non-cyclic pathway. Describe what is happening.

In the non-cyclic pathway, sunlight causes electrons from photosystem two to go through an electron transport system, enter photosystem one, travel through asecond transport system, then wind up in NADPH. Sunlight from photosystem one alsosplits water into oxygen, hydrogen ions and electrons. ATP is formed from releasedenergy in the first electron transport system.

Light Dependent Reactions:Cyclic and Non-cyclic Pathways

In the cyclic pathway, sunlight causes electrons to go from photosystem one through an electron transport system and back to photosystem one. Energyreleased in the electron transport system is used to form ATP.

Answer Key - After Viewing Activity 1


Answer Key - After Viewing Activity 2

Compare and Contrast Using the Venn diagram below, compare and contrast the cyclic and non-cyclic pathways.

CYCL

ICPA

THW

AY

NON-CYCLICPA

THW

AY

CYCLICAND

NON-CYCLIC PATHWAYS

Electrons move in acyclical pattern

ADP is changed to ATP here

Needs sunlight

Have electrontransport system

Forms ATP

Gives up electrons Needs sunlight

Have electrontransport system

Forms ATP

Gives up electrons


Answer Key - After Viewing Quiz 1

Vocabulary QuizFill in the blanks with the appropriate words from the vocabulary list.

PHOTONS - (n) packets of light energyCHLOROPLAST - n) plant organelle where photosynthesis takes placeSTOMA - (n) mouth-like opening of a leaf, allowing passage of carbon

dioxide and oxygenXYLEM - (n) part of plant vein that carries water from root systemPHLOEM - (n) part of plant vein that carries food to the rest of the plantTHYLAKOID - (n) membrane where light reactions of photosynthesis are

carried outGRANUM - (n) stacks of thylakoid membranesSTROMA - (n) fluid that surrounds the thylakoid and where the dark

reactions occurCARBON - (n) element present in all living matterCHLOROPHYLL - (n) a green pigment essential to photosynthesis

1. After sucrose is manufactured in the leaf, it is carried via the

to feed the rest of the plant.

2. You can find the element in diamonds, coal, and wood.

3. A plant can lose a lot of water during a hot day, which is why each

closes during the hottest part of the day and closes again in the cooler evening.

4. absorbs most of the colors of light waves, except the

green, which bounces back off.

5. The thylakoid membranes are found in stacks called .

6. Water travels from the ground up through the plant’s stem through

the .

7. The light reactions take place inside the chloroplast within

the membrane.

8. The organelle that harvests light energy is the .

9. The is the watery matrix where the dark reactions

of photosynthesis take place.

10. originate on the Sun’s surface and travel to Earth in waves.

PHLOEM

CARBON

STOMA

CHLOROPHYLL

GRANUM

XYLEM

THYLAKOID

CHLOROPLAST

STROMA

PHOTONS



1. _____ Which of the following is the chemical equation representing photosynthesis?

a. ADP-3 + pi-2 + H + H2O

b. ATP-4 + H2O

c. 6CO2 + 6H2O C6H12O6 + 6O2 + 6H2O

d. ADP + 6H2O C6H12O6 + 6H2O

2. _____ What are the two life sustaining byproducts of photosynthesis?

a. sunlight and oxygen

b. carbon dioxide and water

c. water and oxygen

d. oxygen and sugar

3. _____ What are the openings found on the underside of the leaf called?

a. stroma

b. stomata

c. chloroplast

d. mesophyll

4. _____ Which of the following is the substance that allows photosynthesis to occur?

a. sucrose

b. chlorophyll

c. lactose

d. all of the above

5. _____ T he sugar assembly takes place in the ________________.

a. stroma

b. granum

c. mesophyll

d. all of the above

6. _____ Where do the light reactions of photosynthesis take place?

a. the inner membrane of the chloroplast

b. the thylakoid membrane

c. the Calvin-Benson cycle

d. the electron of NADPH

Photosynthesis QuizWrite the letter of the best answer in the space provided, fill in the blank with the best answer, or writetrue or false for each statement.

C

D

A

B

A

B



Photosynthesis Quiz (cont.)7. _____ During what two seasons is chlorophyll the predominant pigment in a leaf?

a. summer and fall

b. fall and winter

c. winter and spring

d. spring and summer


a. ___________________________________________________________________

b. ___________________________________________________________________

9. What are the two characteristics of chlorophyll?

a. ___________________________________________________________________

b. ___________________________________________________________________

10. What are the two membranes of the stroma?

a. ___________________________________________________________________

b. ___________________________________________________________________

11. __________ True or False? Thylakoid membranes are found in stacks called mesophyll.

12. __________ True or False? ATP is produced as a result of the build-up of

hydrogen ions.

13. __________ True or False? The light reactions are also known as the

Calvin-Benson cycle.

14. __________ True or False? Light-dependent reactions occur at an intricate

membrane system called the thylakoid membrane system.

15. __________ True or False? The mesophyll is where most of the photosynthesizing

in a plant takes place.

D

F

T

F

T

T

CARBONENERGY

MAIN PIGMENT FOUND IN PHOTOSYNTHESIS ORGANISMSIT IS GREEN SINCE IT TRANSMITS GREEN LIGHT

INNER MEMBRANEOUTER MEMBRANE

Script


SCENE ONE - INTRODUCTION

ANNOUNCERAnd now here’s…your eyes and ears on the world… It’s time for Science News with Kevinand Laura!

KEVINGood day, I’m Kevin Leaf

LAURAAnd I’m Laura Plast.

KEVINWhat a story we have for you folks today!

LAURAIt’s a natural phenomenon beyond belief.

KEVINFolks, we’re not talking about anything as trivial as a major tornado…

LAURAOr a mere hurricane…

KEVINOr one of those run-of-the mill earthquakes.

LAURAOr one of those stupid tidal waves…

KEVINOr one of those silly little floods…

LAURAOr one of those ridiculously common typhoons…

CASTAnnouncerKevin Leaf ..................................................................................anchorLaura Plast ..................................................................................anchorPhil Chloro ..........................................................................weathermanN’ Science ..........................................................................music groupSuzie Skyview ..............................................................on-site reporterKid 1 ............................................................................commercial actorKid 2 ............................................................................commercial actorSpokesperson ..............................................Chloro Cruncheez CerealJohnny Spectrum ..........................................................correspondentJ.J. Carboni ....................................................................sports reporter

Script


KEVINNo, folks, we have no dull and boring catastrophe of nature to report. what we have todayastounds the imagination!

LAURABoggles the mind!

KEVINWill have you on the edge of your seats! Shall we tell them Laura?

LAURAYes! We’ve just discovered a news story that affects more different organisms worldwide thanalmost any other.

KEVINThe impact of the story is astounding. It has to do with the air we breathe.

LAURAThe food we eat

KEVINThe plants we grow

LAURAWe’re talking about…

KEVIN & LAURAPHOTOSYNTHESIS!!

KEVINIt’s so exciting!!

LAURAIt’s wild and crazy!

KEVINIt’s the news story of the century. For that matter, of all time!!

LAURASo on with the story, Kevin. Let’s tell the viewers all about this amazing event!!

KEVINThanks, Laura. Now as you know, carbon-based compounds also known, as the buildingblocks and energy stores of life, are assembled by plants through photosynthesis.

LAURAKevin, I assume these carbon-based compounds you are referring to would be carbohydrates,such as sugars and starches?

KEVINThat’s right. Sugars and starches are put together by plants in a series of chemical reactions.Through photosynthesis plants synthesize food using light energy!

LAURAFascinating! So plants actually make their own food from light! How?

Script

KEVINThat’s what we’re here to find out! You see, even though photosynthesis is the largest and most important manufacturing process in the world, it is also one of the most complex! Let’s start by taking a look at the chemical equation for this process.

LAURAGood idea!

KEVINWe here at Science News always use chemical equations to describe chemical reactions.

LAURAThat’s right, Kevin because the equations tell us just about everything we want to know. Theydescribe the reactants - what we begin with - and the products - what we end up with.

KEVINThe overall equation for photosynthesis tells us that water and carbon dioxide, with the helpof sunlight, is converted into oxygen, simple sugars, and water. It’s this process that enablesall of us to exist.

LAURAYes indeed. The simple sugars produced by plants provide food for humans and otheranimals. In fact, photosynthesizing plants are at the heart of most food webs. We couldn’tsurvive without the food that plants make.

KEVINI certainly couldn’t live without sugar and starch! But seriously, what’s amazing is that this food comes simply from sunlight, water and carbon dioxide.

LAURATalk about a renewable energy source! It’s hard to believe that photosynthesis began onEarth two and a third billion years ago, and we’re just catching wind of this story today.

KEVINSpeaking of wind, it’s those photosynthesizing organisms that caused our atmosphere toaccumulate oxygen gas.

LAURAWow! So we really do rely on photosynthesis to survive! It provides us with food to eat andair to breathe!

KEVINThat’s right! Photosynthesis is everywhere the sun is shining. And to make sure its still goingon outside let’s check the weather with Phil Chloro.

PHILThanks, Kevin. Today’s weather calls for all sorts of conditions that support photosynthesis. Inthe northern US, pine and oak trees are photosynthesizing. In the southwestern US, cacti andother desert plants are soaking up the sun and making food.

Even in the sea, plants, photosynthesizing bacteria and protists are converting carbon dioxideand water into usable energy.

LAURAExcuse me, Phil. Did you say photosynthesizing bacteria and protists?


Script


SCENE FIVE - AUTOTROPHS & HETEROTROPHS

PHILYes, Laura. Bacteria are microscopic one-celled organisms also known as monerans. Moneraare so tiny they do not even house a nucleus. Protists are also unicellular, but they do have anucleus to control the function of the cell. So a number of protists are capable of animal-likemovements.

LAURAI see, but these are still very tiny forms of life we are talking about here.

PHILOh, yes. The tiniest!

LAURAEven the tiny one-celled organisms are involved in photosynthesis?

PHILAbsolutely, these surfing photosynthesizers – bacteria and protists - soak up nearly half of thecarbon dioxide that humans release through the burning of fossil fuels and forests.

KEVINAmazing! So there must be billions of the bacteria and protists in the sea!

PHILExactly. Just one cup of seawater holds twenty-four million cells of just one species.

KEVINIncredible! It makes you wonder what would happen if the oceans weren’t filled with thesephotosynthesizing creatures. I mean, what would happen to all the carbon dioxide thathumans spew into the air?

PHILIt’s hard to say. One prediction is that the excess carbon dioxide would trap heat from thesun, and the earth would radically heat up. Pretty scary.

LAURAIt sounds like we’re really dependent on photosynthesizing organisms not just for food, but forthe balance they create in nature.

PHILThat’s correct. Let me tell you more about the kinds of organisms that photosynthesize.

All over the world, in all types of weather, these photosynthetic autotrophs, such as plants,certain protistans and certain bacteria get energy from the sun. They’re called autotrophsbecause they actually produce their own food by taking carbon and energy directly from theenvironment. Autotroph means self-nourishing.

LAURASo, in other words, all the plants and organisms on land and in the sea that photosynthesizeare autotrophs because they feed themselves!

Script

PHILRight! And as far as the weather is concerned, there’s not much more to say. All over the globe today, just as there has been for over 3 billion years; we have enough sunlight for photosynthesis.

LAURAThat’s good news. Thanks for a very informative report, Phil. And now, on Science Net, it’stime for one of my favorite segments. “N’Science” is here with a musical tribute to our topstory: Photosynthesis!

N’ SCIENCE Here comes the sunIt’s time for funLet’s check it out And have no doubt!

Pho-to-syn-the-sis!It’s happening!Pho-to-syn-the-sis!It’s the big thing!

Take water and carbon dioxideAdd sunlight and simply stand asideThe process is smooth, not real harsh,Before you know it, you got oxygen, starch and sugarPho-to-syn-the-sis!It’s changing!Pho-to-syn-the-sis!Re-arranging!

Plants all over photosynthesizeBig and small…hey! Every size!That make their own food they work real hard, don’t hardly loaf,They go by the name of autotroph

Pho-to-syn-the-sis!It’s making foodPho-to-syn-the-sis!It’s all good

Pho-to-syn-the-sis!In the sea and on landPho-to-syn-the-sis!Let’s give it a hand!

KEVINGreat job, N’ Science! What a super song! You know, Laura we’ve already seen that Photosynthesis is indeed “happening. ” We know that it is the basis for the food we eat and the air we breathe. We also know that it helps maintain a balance in nature and makes it possible for us all to survive. This story is really big! And we’ve barely scratched the surface. There’s so much more to learn about photosynthesis!

LAURAThat’s right, Kevin! For instance, we know that most plants are autotrophs, right.

KEVINRight.


Script


LAURANow, I eat plants so that makes me a heterotroph. Heterotrophs, such as myself, arenourished by other organisms, including autotrophs. We don’t synthesize our own food. Youknow, Kevin, it sure feels good to be at the top of the food chain.

KEVINNow Laura, don’t think you’re so special just because you’re a heterotroph. You share that illustrious title with fungi, most bacteria, many protistans and other animals.

LAURAReally? So not all bacteria and protists are autotrophs, huh?

KEVINNo. Far from it. Most bacteria feed off other organisms.

LAURAI see.

KEVINJust as fungi feed off other plants and organisms.

LAURASo I have something in common with a mushroom? We’re both heterotrophs!

SCENE EIGHT - PLANT PHYSIOLOGY

KEVINExactly. Well, I understand that Suzie Skyview, our traffic reporter just radioed in. Let’s checkin with Suzie and see what’s happening on our streets and freeways.

SUZIEThanks Kevin. Traffic looks totally jammed everywhere. If it weren’t for thosephotosynthesizing plants soaking up all the carbon dioxide and slowing global warming, we’dhave a hole in the ozone layer right over route twenty-one!

LAURASusie. Can you actually show us some of the photosynthesis going on?

SUSIERight now I’m over Harmony Park checking out the trees, bushes, and grass. From up herethings look pretty stable. I can’t see any photosynthesis yet, but I’m sure it’s happening. Letme get a bit closer. I’m not seeing anything yet. Let’s land this thing.

SUSIEHmmm. Just leafy plants. Better get out the microscope. Now this is much better. Here yousee all the layers inside the leaf. This outer most layer is called the Epidermis. The epidermis isa waterproof coating that helps prevent water loss. Of course, water and oxygen do getreleased from leaves – by a process called transpiration.

LAURATranspiration? That’s part of the water cycle right? From what I hear plants lose hugeamounts of water through transpiration.

Script

SUSIECorrect, Laura. Transpiration from plants is a major factor in the production of clouds andtherefore rainfall. And some of the water loss through transpiration is remarkable. Forexample, a full-grown birch tree releases about 17,000 liters of water in a single summer. Andthe grass on a football field can lose almost 3,000 liters of water on one summer day!

LAURASo that epidermis isn’t really working is it? I mean, isn’t it supposed to prevent water loss?

SUSIEWell, believe it or not the release of water and oxygen is controlled through a microscopicopening in the epidermis called a stoma. Stoma is a Greek word that means mouth.

KEVINYou know that stoma does look a little like a tiny mouth!

SUSIEThat’s right, Kevin. And the stoma is not only where water and oxygen exit the leaf, it is alsowhere carbon dioxide enters the leaf.

LAURAThe stoma really chews up all that carbon dioxide, huh?

SUSIEExactly, the stoma runs through the middle of the leaf called the mesophyll.

KEVINMesophyll? Sounds Greek to me.

SUSIEIt is, Kevin. Meso means middle and phyll means leaf.

KEVINPhyll means leaf?

SUSIECorrect.

KEVINSo I’d be Kevin Phyll in greek?

SCENE ELEVEN - INSERT TITLE HERE

SUSIEI suppose so, Kevin. Anyway it is here in the mesophyll that almost all the photosynthesizingtakes place. Let’s take a closer look…

Ah yes! Here are the little photosynthetic cells and here are the chloroplasts, you know, theorganelles found in photosynthesizing plants. This is where photosynthesis takes place. Checkit out. Talk about traffic! There’s a lot of congestion in here. First there’s the stroma or semi-fluid interior of the chloroplast.


Script


LAURAI thought the stroma was the little mouth opening in the epidermis of the leaf.

SUSIENo, that’s the stoma.

LAURAThat’s what I said, Stroma.

SUSIENo, No, Laura. Stroma and Stoma, they are two totally different parts. The Stoma is themouth opening in the epidermis of the leaf. We are talking about the Stroma. It is the semi-fluid interior of the chloroplast.

LAURAStroma, Stoma. Got It!

SUSIEAnyway…. Two membranes surround the stroma. The inner membrane weaves through thestroma and makes flattened disks. The disks make little stacks called grana. All the granumwithin the stroma of the chloroplast makes up the thylakoid membrane system.

LAURAWow! Let’s give our viewers another look at the parts of the chloroplasts. These littleorganelles are incredible!

KEVINOK. Here’s the interior or stroma. The little stacks of disks are grana. The granum andchannels that connect them make up the thylakoid membrane system. Suzie, what happens inhere?

SCENE TWELVE - ATP PRODUCTION

SUSIEI’m sure glad you asked. This is where the first stage of photosynthesis, the light-dependentstage takes place. The grana and channels store hydrogen ions for ATP production. ATP,adenosine triphosphate is the molecule that carries energy in cells. The stroma’s important,too. Sugars get assembled there in the second stage, the light-independent stage, ofphotosynthesis.

KEVINSo what you’re saying is that photosynthesis has two parts. ATP production in the thylakoidmembrane system then sugars assembly in the stroma.

SUSIEThat’s right, Kevin. The first part, ATP production in the thylakoid membrane system requiressunlight. That’s why we call it light dependent. The sugar assembly in the stroma doesn’trequire the sun. That’s why we call it light independent.

LAURAWow Susie. You make it sound so simple.

SUSIEAnything is simple, once you understand it. It’s time for me to take off. I have to get back tothe skies and check out how those heterotrophs driving their cars are doing on the freeways.Back to you Laura.

Script

LAURAThanks Suzie. Great job! Well, it looks like N’ Science is ready with another song about ourbig story: Photosynthesis. So, let’s do it!

N’ SCIENCEInside the leaf is where it’s atThat mesophyll, to be exact!Right here is where things really get fastDeep inside the chloroplast!

These granum stacks are really greatThey help make Adenosine triphosphateThat ATP, is all the rageIt’s the light-dependent stageATP carries energy in the cellAnd makes photosynthesis work so wellBut the stroma is important too!It’s where plants make their sugary glue.

So when you think about how photosynthesis startsRemember there are two distinct partsOne needs light to make energyIn the thylakoid membrane system, see!

The other part works without lightMaking food, like sugar, out of sightYeah, the sugar-making stroma doesn’t need sunTo help make photosynthesis run.

Inside the leaf that’s where it’s atThe mesophyll to be exactThat’s photosynthesis front and backYou got it now, and that’s a fact!

LAURAWe’ll be back with more news after this message from our sponsor.

SCENE THIRTEEN - CHLORO CRUNCHEEZ

KID 1Geez, I sure wish we didn’t have to spend another day in the sun soaking up nothing butultraviolet rays.

KID 2Yeah. Wouldn’t it be cool if we could convert energy from the sun into food likephotosynthesizing plants?

KID 1Oh sure, we’d have to be full of chloroplasts with pigments in them. You know, likechlorophyll.

SPOKESPERSONWell, I’ve got just the cereal you’ve been wishing for. Introducing new Chloro Cruncheez!Packed with that super-duper organelle found in plant cells known as the chloroplast, ChloroCruncheez contains lots of pigments. These chemicals absorb light and trap packets of energyor photons from the sun. Like most green plants, Chloro Cruncheez is loaded with the pigmentchlorophyll. This pigment absorbs violet, blue, and red light, but transmits green light, so it


Script


appears…green!

KIDS 1 & 2No way!

SPOKESPERSONChloro Cruncheez even contains the recommended daily allowance of carotenoids, pigmentsthat absorb violet and blue light, but transmit red, yellow, and orange light.

KID 1Hey! Does that mean that if we eat Chloro Cruncheez that we’ll change color like the leaves in autumn?

SPOKESPERSONMaybe if you eat enough Chloro Cruncheez, young lady. One thing I do know [pause] you’llget enough sugar to send you to the moon and back.

KID 1 & 2Cool!

SPOKESPERSONSo make Chloro Cruncheez a part of your breakfast every day. Try it for a snack or for lunch,or maybe even dinner.

KIDS 1 & 2We’re mean, green, photosynthesis machines, and we love our Chloro Cruncheez!

ANNOUNCERChloro Cruncheez contains no more chloroplasts than typical green plants consumed byhumans. Digesting such chloroplasts does in no way cause people to undergo any stage ofphotosynthesis or synthesize simple sugars such as glucose or fructose. Excessive ingestion ofChloro Cruncheez results in the skin fading to green as result of a risky chemical not yetapproved by the Food and Drug Administration. Consume at your own risk.

SCENE FOURTEEN - CHLOROPHYLL & CAROTENOIDS

KEVINWelcome back to Science News. All the news that really is matter. If you just tuned in, our topstory today is photosynthesis.

LAURAAs always, we bring you the stories while they are happening. We just got word from our livecorrespondent – Johnny Spectrum. He’s on the on the scene and ready to report. Johnny?

JOHNNYThanks Laura. I’m here right smack dab in the middle of a sunny day, out in the sunlight—it’sincredible! Just think: billions of billions of cells are engaged in the first stage ofphotosynthesis right now. Inside those chloroplasts, specifically the thylakoid membranesystem, the light-dependent reactions are proceeding.

KEVINJohnny. Before you go on, could you quickly review some principles of light that areimportant?

Script

JOHNNYSure thing, Kevin! Pigments are molecules that absorb light. They trap packets of energy,called photons, from the sun. Light also behaves like a wave so that different colors of lighthave different frequencies and wavelengths.

Light waves with more energy have higher frequencies and shorter wavelengths. Light waveswith less energy have lower frequencies and longer wavelengths.

Each pigment absorbs a characteristic wavelength of light. Chlorophyll a is the main pigmentfound in photosynthesizing organisms. To us, chlorophyll a is green since it transmits greenlight. Carotenoids, other pigments, are red, orange, and yellow.

JOHNNYThese pigments are more visible in autumn when many plants stop producing chlorophyll.

LAURAThat is fascinating. Just by the color of the leaf, we can tell which pigments are predominant.In the summer and spring, it’s chlorophyll. In the winter and fall, it’s carotenoids.

SCENE SIXTEEN - LIGHT-DEPENDENT REACTIONS

JOHNNYCarotenoids and other pigments, besides chlorophyll a, absorb energy and transfer it tochlorophyll a.

KEVINJohnny, just how do these light absorbing molecules lead to the production of food?

JOHNNYWell, let’s take a close look at the light-dependent reactions.

Photosystems, which are clusters of pigments in the thylakoid membrane system, absorbsunlight energy and give up electrons. Electrons are transferred to an acceptor molecule,which donates them to a transport system in the membrane.

ATP, the main energy carrier, is formed by one of two different pathways, depending on theplant.

JOHNNYThe first pathway is called the cyclic pathway and occurs in trees, weeds and other leafyplants. It’s easy to describe. It’s, well, cyclic. In other words electrons from photosystem one,thanks to chlorophyll, cycle through a transport system and back to photosystem one.

SCENE SEVENTEEN - CYCLIC PATHWAY

LAURAWait a minute, Johnny. These transport systems in plants, are they like tiny subways orsomething?

JOHNNYNo, not quite… I’d better define an electron transport system. It’s a sequence of enzymes andother proteins in a cell membrane.

KEVINSo the transport system is more like a wire carrying electricity?


Script


JOHNNYRight. And as fired-up electrons travel through it, energy released by the electrons is used tochange ADP, adenosine diphosphate, and an unbound phosphate ion to ATP, adenosinetriphosphate.

KEVINSo, ADP is changed during this cyclic light-dependent reaction to ATP? Interesting. And yousay energy is released during the electron transport? Where does it go?

JOHNNYGood question, Kevin. It’s stored in the ATP molecule.

The second and dominant pathway is cleverly named the non-cyclic pathway. Electrons aren’tcycled here.

In this pathway, electrons leave the system attached to NADP, a coenzyme that carries twoelectrons and a hydrogen ion. Then electrons from water molecules replace them.

SCENE EIGHTEEN - NON-CYCLIC PATHWAY

LAURAAh ha! I was wondering when we’d get to the water part. I remember the “reactants” in thephotosynthesis equation were carbon dioxide and water.

JOHNNYExactly And here’s what happens in the non-cyclic pathway.

To begin, the sun’s energy is trapped by photosystem two, which in turn gives up an electron.This triggers photolysis, the cutting of water into oxygen, hydrogen ions and electrons. Theoxygen is given off, the hydrogen ions stay in the thylakoid membrane system, and the ratherunexcited electrons replace the excited ones that took off to enter an electron transportsystem.

Energy released in the electron transport system is used to form ATP from ADP and anunbound phosphate.

After the electrons leave the first transport system, they end up at photosystem one. Nowremember these electrons are still hyped up AND photosystem one is absorbing photons fromthe sun.

SCENE NINETEEN - NADP & NADPHKEVINSo, it looks like what we have there are some super duper excited electrons.

JOHNNYRight, Kevin. The electrons get so excited they move off to enter yet another transport system.

In this system, the enzyme helper NADP picks up two electrons and a hydrogen ion. The newNADPH molecule whisks the hydrogen ion and two electrons to the second stage ofphotosynthesis, the light independent reactions.

LAURAThanks Johnny. Sounds like he’s really into photosynthesis. Like we said it does get prettycomplicated but I think the key points are…be a plant, absorb light, make ATP.

Script

KEVINI think we’d better summarize the cyclic and non-cyclic pathways in a little more detail. Its notas simple as be a plant, absorb light, make ATP.

LAURAOk. Here’s a comparison between the cyclic and non-cyclic pathways. In the cyclic pathway,sunlight causes electrons to go from photosystem one through an electron transport systemand back to photosystem one. Energy released in the electron transport system is used to formATP.

KEVINIn the non-cyclic pathway, sunlight causes electrons from photosystem two to go through anelectron transport system, enter photosystem one, travel through a second transport system,then wind up in NADPH. Sunlight from photosystem one also splits water into oxygen,hydrogen ions and electrons. ATP is formed from released energy in the first electrontransport system.

LAURAThat’s it for the light-dependent reactions. We’ll be right back after this with more news,information, and more of today’s top story: Photosynthesis. Right after this…

ANNOUNCERAnd now it’s time for Science Poetry. Today’s poem is called Photosynthesis Pathways by E.Electron.

Two pathways diverge in woody plantsOne cyclic, one not – transporting electron antsOn the cyclic pathway electrons spinFrom one photosystem and back to itself againAnd within this circle I can seeEnergy released forming ATP.On the non-cyclic pathway is something newElectrons entering one photosystem and passing throughOn to a second and a change it makesWhen it turns into NADPH!So, what did I do? Which path did I treadWell, as I am an electron, I was leadI had no choice. I had to tryI took the one less traveled by.

LAURAWelcome back to Science News. Next up. Sports. And who better to give you today’s scoresand highlights than channel two’s very own JJ Carboni.

JJThanks Laura. How can we even discuss football, basketball, baseball or even the Olympic games with this photosynthesis thing going on?

KEVINYou’ve got a point there, JJ.

JJI mean, Photosynthesis is simply amazing. Sometimes it can be a bit tricky, but then again soare some of the plays I run on the football field. Maybe I can help you keep score of allthose electrons and molecules running plays as they assemble carbohydrates in the light-independent stage of photosynthesis.


Script


KEVINThat would be great, JJ.

SCENE TWENTY THREE - LIGHT-INDEPENDENT REACTIONS

JJNow remember how Johnny Spectrum was saying that in the light-dependent reactions, ATPand NADPH were formed. And remember that the overall equation for photosynthesis showscarbon dioxide as a reactant. Well, when you see how it all comes together, you’re going tothink you’re watching a highlight reel. Talk about your play of the game.

Anyway, let’s look at the players in the sugar-making game, the synthesis part ofphotosynthesis – the light-independent reactions.

The line-up includes several important molecules. The ATP delivers energy, the NADPHdelivers hydrogen and electrons, and carbon dioxide provides the carbon and oxygen.

The light dependent reaction kick-off with a big offensive play—the capture of carbon dioxidecalled carbon dioxide fixation.

A five-carbon molecule called RUBP sacks a carbon dioxide molecule and steals its carbonatom. The product is a six-carbon rather unstable intermediate.

This starts a cyclic pathway that yields sugar phosphates and regenerates the RUBP. Like allgreat plays, it has a name—the Calvin-Benson cycle.

Let’s follow the carbon atoms as they run the play.

Carbon from the air diffuses across the plasma membrane into the stroma of the chloroplast.The carbon attaches to RUBP. This newly formed unstable molecule quickly splits into twothree-carbon molecules called phosphoglycerate or PGA.

The ATP donates phosphate and NADPH hands off hydrogen and electrons to turn each PGAto phosphoglyceraldehyde or PGAL. The play is run six times.

Then most of the PGAL gets converted to RUBP, but two PGALs combine to make a six-carbonsugar phosphate. Touchdown! The sugar phosphate end product is why photosynthesis takesplace. This is the molecule that gets converted into food, like sucrose, starch, and cellulose. Wow! What an amazing game. The Calvin-Benson cycle is a must in any photosynthesizingplaybook!

SCENE TWENTY FIVE - REVIEW

LAURAThanks for your enthusiastic report, JJ. Let’s recap briefly some of today’s important stories…

KEVINWe began Laura by noting that Photosynthesis is a process in which food is synthesized usinglight energy. We also looked at the chemical equation for photosynthesis.

LAURARight. That showed us that sunlight and chlorophyll go into the products – glucose andoxygen, where they transform the reactants –carbon dioxide and oxygen. These feed theplants and give us air to breathe!

Script

KEVINNext we learned that all photosynthesizing plants – even tiny bacteria and protistans – areautotrophs. Which means they produce their own food.

LAURARight. And organisms that are nourished by other organisms, such as people, animals, fungi,and most bacteria, are called heterotrophs.

KEVINWe also took a look inside a leaf and saw the mesophyll where most of the photosynthesizingtakes place.

LAURARight. Susie Skyview also showed us that inside the mesophyll are numerous photosyntheticcells and inside those cells are chloroplasts, the organelle of photosynthesis.

KEVINWe also saw that within the photosynthetic cell two types of reactions occur. Light-dependentreactions proceed at an intricate membrane system called the thylakoid membrane system.

LAURAAnd “light-independent” reactions proceed within the stroma.

KEVINWe learned so much, Laura… We learned that chlorophyll is a green pigment within thechloroplast. And those red, orange, and yellow pigments are called carotenoids.

LAURAAnd that’s important because as the chemical equation showed us it takes sunlight andchlorophyll to promote photosynthesis.

KEVINRemember also that Johnny Spectrum talked about the two types of light-dependent reactions– the cyclic pathway and non-cyclic pathway.

LAURAAnd of course, JJ Carboni’s personal favorite the Calvin-Benson Cycle which is how sugar issynthesized with a light-independent reaction. N’ Science tells us more!

LAB RAPSThat’s all there is, you got it allWe covered Photosynthesis big and smallWhen it comes to learning this and thatScience News brings you the facts!

KEVINThat’s right N’ Science! That is it for Science News today. I think we’ve shown thatPhotosynthesis is an incredible process that we could not be without! I’m glad we had achance to find out all about it!

LAURAWell, that about sums up our amazing news story, Kevin!

KEVINRight, Laura


Script


LAURAMy goodness, I’ve learned so much! Kevin what do you think I’ll tell my friends the next timethey say to me, “Get a life!”

KEVINGee, I don’t know. what will you say?

LAURAGet a leaf!

KEVINYeah, I like that! Get a leaf! You’ve coined a brand new expression, Laura.

LAURAAs you viewers can see, we’ve presented you with a one-of-a-kind news story.

KEVINWe may get an emmy for this one.

LAURAGee, I hope so! But I’ll say one thing! I know I have a new found respect for that salad andcorn when it gets placed on the dinner table tonight. I’m Laura Plast

KEVINAnd I’m Kevin Leaf. We hope you all have a sunny photosynthesizing day!

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