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Why do we need O2?
How do cells acquire and use energy?Cellular Respiration and Photosynthesis
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Study Guide• Define and compare autotrophs and heterotrophs, producers and consumers.
• Explain how the processes of photosynthesis and cellular respiration are complementary to each other.
• Compare the processes of cellular respiration and breathing.
• Write and explain the overall equation for cellular respiration.
• Compare the reactants, products, and energy yield of the stages of respiration (glycolysis, formation of acetyl‐CoA, Krebs cycle, and electron transport chain), then indicate where each process occurs in the cell.
• Compare the reactants, products and energy yield between aerobic and anaerobic respiration
• Compare the reactants, products, and energy yield of fermentation in human and yeast cells, and bacteria, then indicate where this process occurs these cells.
• Describe the structure of chloroplasts, and indicate the function and location of chlorophyll molecules.
• Compare the reactants and products of the light reactions and the Calvin cycle.
• Describe the reactants and products of the Calvin cycle.
• Explain the similarities and differences between the process of cellular respiration and photosynthesis
MetabolismThe sum of all chemical reactions that occur in a cell
Each chemical reaction requires a particular enzyme
Some chemical reactions store energy and some release energy
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Menu
review of chemical reactions
function of ATP
cellular respiration
types of cellular respiration
steps of cellular respiration
photosynthesis
steps of photosynthesis
Review of chemical reactions
What is a chemical reaction?
Which are the reactants and products?
Was matter created or destroyed?
Was energy created or destroyed?
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ATP is the nucleotide used as the cell’s energy currency
• The 3rd bond between the phosphate groups is a high‐energy bond
• Energy is required to form the bond and
• Energy is released when the bonds are broken
• ATP is continually produced and consumed (10 million ATP per second each cell)
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Anything that prevents ATP formation will most likely ____.
1. Result in cell death
2. Force the cell to rely on lipids for energy
3. Force the cell to rely on ADP for energy
4. Have no effect on the cell
The overall reaction of Cellular Respiration
Series of chemical reactions that
transform chemical energy in food (organic molecules)
to a usable form of chemical energy (ATP)
What reactants need to be present for cell respiration to occur?
What is produced during cellular respiration?
Which organisms carryout cellular respiration?
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Chemical energy in the glucose bonds is transferred to the bond holding the third phosphate group in ATP
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During cellular respiration oxygen molecule gains the hydrogens from glucose forming water
In an experiment, mice were fed glucose containing a small amount of
radioactive oxygen atoms. The mice were closely monitored, and in a few
minutes radioactive oxygen atoms showed up in _____.
a) ATP
b) oxygen gas
c) carbon dioxide
d) water
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Hydrogen transfer (from glucose to oxygen molecule) is not direct
Hydrogen atoms are removed in 3 steps________________________________________________________________________
And they are carried (shuttled) by NAD
NAD + H NADH
In the 4th step, ________________,NADH pass their hydrogen atoms to oxygen moleculesforming water and releasing energy
NADH
is a carrier of hydrogens (energy)
What you need to know about CR
For each step:
Where does it take place?
Energy yield as ATP?
Energy yield as NADH?
Which of the overall reactants
are consumed?
Which of the overall products
are produced?
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TEST YOUR UNDERSTANDING
Why do we need O2?
A. O2 helps us synthesize proteins. B. It counterbalances the CO2 in the atmosphere. C. O2 plays a role in obtaining energy from food. D. O2 is needed to deliver hemoglobin to our cells. E. to make CO2.
Immediately after completion of the Krebs cycle, most of the energy from the original glucose molecule is in the form of ___________.
A. ATPB. CO2
C. CoAD. acetic acidE. NADH
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Anaerobic respiration is an alternative when oxygen is not present
Where in the cell does anaerobic respiration takes place?
If O2 is present what type of respiration will these organisms do?
Lactic acid fermentation
• in animals and bacteria
• Glucose 2 Lactic acid + Energy
• Steps:
Glycolysis (2 ATP)
+
Regeneration of NAD
(Lactic acid as waste product)
Alcoholic fermentation
• in yeast
• Glucose 2 ethanol +CO2 + Energy
• Steps:
Glycolysis (2ATP)
+
Regeneration of NAD
(Ethanol + CO2 as waste products)
Is GLUCOSE the only source of our energy?
Cells use many organic molecules as fuel for cellular respiration
Digestive tractBreaks down macromoleculesin to their monomers
Monomers can enter cellular respiration at different stages
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Which part of the breakdown of glucose requires oxygen molecules?
A. fermentation
B. the Krebs cycle
C. glycolysis
D. the electron transport chain
E. all of the choices
•If humans did not breathe in O2, we would NOT ______.
A. be affected because we can switch to alcoholic fermentation
B. have enough enzymes to catalyze reactions
C. make enough ATP to meet our energy requirements
D. be able to perform
lactic acid fermentation forever
E. be able to synthesize organic molecules
from inorganic molecules
We obtain energy from our food…
But where did the energy in our food come from
in the first place?
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The Overall reaction of Photosynthesis
Series of reactions thatstores the light energy (sun) into chemical energy (organic molecules)
What reactants need to be present for photosynthesis to occur?
Which is the source the matter and energy in the glucose molecule?
What is produced during photosynthesis?
Which organisms carryout photosynthesis?
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Photosynthesisstores light energy into organic molecules
Photosynthesis takes place in chloroplasts
Chlorophyll and other pigments are in charge of capturing light energy
These pigments are found in the thylakoid membranes
Stroma is the space between the inner membrane and the thylakoids
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Photosynthesis occurs in two stagesinked by ATP and NADPH
For each step:
Where does it take place?
Energy transformation?
Which of the overall reactants
are consumed?
Which of the overall products
are produced?
Fill out chart
What happens to the glucose produced by photosynthesis?
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Where does it take place in the cell?
What happens to the hydrogen atoms?
Who shuttles the hydrogen atoms?
Photosynthesis and Cellular Respiration
Photosynthesis and Cellular Respiration
CO2 + H2O CO2 + H2O
Glucose + O2
What is wrong with the following statement:Animals do cellular respiration and plants do photosynthesis
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Life requires energy
Your energy ultimately comes from …
Life requires matter
Your matter ultimately comes from…
The connection between
photosynthesis and cellular respiration
Cellular Respiration and Photosynthesis Lab
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Phenol Red is an indicator of amount of Carbon Dioxide in a solution
+++CO2 ++CO2+CO2
If we add CO2 to the phenol red, what will be the color of “phenol red”?
If we remove CO2 from the phenol, what will be the color?
Aerobic respiration of Peas
Reaction of Aerobic Respiration:
Peas: embryo plants (alive) + nutrients
use more peas!!!
Embryo extracts energy from nutrients
via aerobic respiration
What will the peas consume from the surrounding solution?
What will the peas produce into the surrounding solution?
How can we detect if peas carrying out aerobic respiration?
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Set up (one/group of 4)
•Materials:‐test tube with phenol red‐test tube rack‐3 peas
•Clean up:‐do not throw away peas, return them‐dispose of phenol read in designated container‐wash materials and return
Fermentation of yeast
Reaction of Anaerobic Respiration (aka Fermentation):
Yeast are unicellular fungi that obtain energyby consuming glucose in flour or fruit juicein absence of oxygen via anaerobic respiration
What will the yeast consume from the solution?
What will the yeast produce into the solution?
How can we detect if yeast are respiring?
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Set up
• Work in groups of four (one person‐one tube)
• Handle fermentation tubes carefully
• Label tubes1: warm yeast only2: warm yeast + sucrose3: warm yeast + protein4: warm yeast + sucrose (in cold)
• Remove air from tube before beginning time count
• Measure displacement of solution after after 30 min
Photosynthesis of Elodea Plant DEMO
Reaction of photosynthesis:
Elodea plants live in freshwater
When elodea is photosynthesizing,
What does it consume from the surrounding liquid?
What does it produce into the surrounding liquid?
How can we detect if the elodea is photosynthesizing?
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Plan of attack
• Groups of four
• Division of work
3 person set up the yeast and fermentation
1 person sets up the pea in phenol red
Elodea in phenol red is a demo
• Fill out tables and answer questions
•Show experiments to your group members before cleanup
Results: Aerobic respiration of PeasWhat do we know from the change of color?
Why did the phenol red change color?
What gas was produced by the peas?
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Results: Fermentation of YeastWhat cause the displacement of the solution?
In which tubes did the yeast carry out fermentation? Why?
In which tubes did the yeast NOT carry out fermentation? Why?
1: warm yeast only
2: warm yeast + sucrose
3: warm yeast + protein
4: yeast + sucrose (in fridge)
Results: Photosynthesis of Elodea DEMO
Why did the phenol red change from yellow to red?
What was the gas produced by the elodea plant?