PhotosynthesisPhotosynthesis

Energy and LifeEnergy and Life

When do living things need energy?When do living things need energy?

§ Just about every activity we do requires Just about every activity we do requires energy!!energy!!

§ Energy is needed to sustain life.Energy is needed to sustain life.

Where does energy come from?Where does energy come from?

§ AutotrophsAutotrophs - Make their own food - Make their own food§Ex: Plants, AlgaeEx: Plants, Algae

§ HeterotrophsHeterotrophs - Obtain nutrients - Obtain nutrients by eating othersby eating others§Ex: Humans, mushrooms, fish, Ex: Humans, mushrooms, fish,

cats, dogscats, dogs

§ In order to live, all organisms including In order to live, all organisms including plants must release energy in sugars and plants must release energy in sugars and other compounds.other compounds.

Fuel for Living ThingsFuel for Living Things

§ Living things need Living things need chemical fuelchemical fuel§ ATPATP is one of the principle is one of the principle

chemical compounds that cells chemical compounds that cells use to use to store and release energy.store and release energy.

What is ATP?What is ATP?

§ Adenosine TriphosphateAdenosine Triphosphate§ Adenosine – Adenine and RiboseAdenosine – Adenine and Ribose§ Triphosphate- 3 phosphate groupsTriphosphate- 3 phosphate groups

Where is the energy in ATP?Where is the energy in ATP?

§ Energy is Energy is storedstored in the in the threethree phosphate phosphate groups.groups.

§ In order to In order to releaserelease energy to be energy to be harnessed for other processes, the harnessed for other processes, the bond bond between the second and third phosphate between the second and third phosphate must be broken.must be broken.

ATP: Basic Energy Source for Cells!ATP: Basic Energy Source for Cells!

§ Can be used for a number of processesCan be used for a number of processes§ Active transport across cell membranesActive transport across cell membranes§ Protein synthesisProtein synthesis§ Nucleic acid synthesisNucleic acid synthesis§ Response to chemical signals at cell surfaceResponse to chemical signals at cell surface§ Produces movement by providing energy for motor proteinsProduces movement by providing energy for motor proteins§ Can even produce light!Can even produce light!§ Muscle contractionMuscle contraction

ATPATP

§ Only found in small amounts in cellsOnly found in small amounts in cells§ Great for transferring energy but not for storing Great for transferring energy but not for storing

large amounts of it long termlarge amounts of it long term§ A single molecule of glucose stores A single molecule of glucose stores 90 times90 times

as much chemical energy than one molecule of as much chemical energy than one molecule of ATP!!!!ATP!!!!

§ More efficient to store a small amountMore efficient to store a small amount§ But, ATP can be regenerated from ADP…But, ATP can be regenerated from ADP…

Photosynthesis

Process of capturing radiant energy from the sun and converting it to

chemical energy – FOOD!

Joseph Priestly

1700’S

Placed a jar over a candle and the flame went out

Put mint and candle under jar and candle remained lit

Plant produced something that kept the candle burning…

We know now it was oxygen!

Melvin Calvin

1900’S

Used carbon 14 to trace the pathway of carbon as it forms

glucose

“Calvin Cycle” part of photosynthesis

Notice the illustrations of the plant leaf below.Notice the illustrations of the plant leaf below.What plant cell organelle do you recognize?What plant cell organelle do you recognize?

ChloroplastChloroplast § Chloroplasts are present Chloroplasts are present in plant cells.in plant cells.

§ They They capture the light capture the light energy from the sun and energy from the sun and convert it into chemical convert it into chemical energyenergy (food molecules (food molecules called called glucose, Cglucose, C66HH1212OO66).).

§ That process is called That process is called PhotosynthesisPhotosynthesis

Sunlight is radiant energy

Light is needed for photosynthesis

*We see colors of light that are reflected

*Other colors are

absorbed

So for a plant leaf to be green, what

color is being reflected????

Gorgeous Fall Color

Chlorophyll dies due to lack of sunlight and colder temperatures

So… other pigments can be seen

In these pictures, what colors are being reflected????

General Equation for Photosynthesis:6CO2 + 6H20 → C6H12O6 + 6O2

Photosynthesis takes place in plants, algae and some bacteria

The main organ is the leaf in photosynthesis

The photosynthetic organelle...

Chloroplast

What organ is this found in????

Let’s figure out the equation for Let’s figure out the equation for Photosynthesis?Photosynthesis?

According to the chloroplast According to the chloroplast diagram to the left….diagram to the left….

§ What is the chloroplast taking in What is the chloroplast taking in (the (the reactantsreactants))??

The same as what we said plants The same as what we said plants need to surviveneed to survive

§ What is the chloroplast What is the chloroplast producing or giving off (the producing or giving off (the productsproducts))??

Glucose(C6H12O6 )

October 7, 2009

Warm – Up (write the questions)

1. What did Priestley say?

2. What did Calvin do?

3. What is an autotroph?

4. What is a heterotroph?

5. What are the products of photosynthesis?

6. What is the organelle of photosynthesis?

7. What kind of light do we see?

ATP ADP

Contains Adenine

Contains Ribose

Contains 3 phosphates

Contains 2 phosphates

“fully charged battery”

“partially charged battery”

• Copy the chart and place an X in the appropriate box…

Absorption of Light

• Do we see light that is absorbed? • Why are leaves green?• You are trying to test whether plants grow

better in green light or in blue light. – What is the independent variable? – What is the dependent variable? – How would we keep this controlled? – Which plant do you think will grow better – the

plant in green light or the plant in blue light? • WHY????

Use your manipulatives to create the Use your manipulatives to create the equation for photosynthesisequation for photosynthesis((Place the correct name of the molecule below it in the equation and make sure Place the correct name of the molecule below it in the equation and make sure your equation is balanced using the correct coefficients)your equation is balanced using the correct coefficients)

ReactantsReactants ProductsProducts

Write out your correct balanced equation of photosynthesis.Write out your correct balanced equation of photosynthesis.

Does your equation look Does your equation look like the one below?like the one below?

Flow of Ingredients and Products:

Reactants: CO2 and H2O (and sunlight)

Products: high Energy compounds and oxygen

Two Parts of Photosynthesis

1. Light-dependent reaction (LDR)

*Occurs in the thylakoid membrane

2. Calvin Cycle or light-independent reaction (dark reaction)

*Occurs in the stroma

Overview of Photosynthesis

LIGHT and WATER

Are used to make

OXYGEN

Summary of the Light Reaction:

Calvin Cycle

MOST COMMON PATHWAY FOR CARBON FIXATION – turning carbon from CO2 into

high energy sugars

Occurs in the stroma

UsingCO2

(from the air)

to PRODUCE GLUCOSE

(what is the formula?)

Factors Affecting the Rate of Photosynthesis

Water – If not enough, photosynthesis can’t occur

Light- Rate increases as intensity increases, then levels off (saturated)

Temperature– As temperature increases, rate increases up to about 35ºC then drops off due too much water loss

** Make sure to draw the graphs!!!!

September 30, 2010

Write the following exactly as it is shown on your lab table in chalk:

PHOTOSYNTHESIS_____ (organ) - _______ (organelle)

Reactants Products

Warm Up

1. Use your manipulatives and correctly lay out the formula for photosynthesis.

2. Label what is used in the LDR. 3. Label what is used in the Calvin Cycle. 4. Label what is made in the LDR. 5. Label what is made in the Calvin Cycle. 6. Draw and label a CHLOROPLAST. 7. Label where the LDR occurs. 8. Label where the Calvin Cycle occurs.

Check your understandingExplain the process of

Photosynthesis using the following

terms : carbon dioxide light energy

glucose food

oxygen gas

process water

chloroplast plants

Write out your explanation using the above terms.

There is a saying “If you talk to a plant, the plant will grow”

Explain how the phrase above is relevant and what process is

taking place.

Think Pair Share