Name _________________________________ Period __________
LESSON 4.2: Powering the Cell- Cellular Respiration
QUICK REVIEW….
What are the two stages of photosynthesis? ____________________________________________________
What happens in the chloroplasts? ___________________________________________________________
Study the cycles, reactants and products labeled in the picture below….
Color stage/cycle names in yellow (2 items); Color reactants and products in light green (8 items)
LIGHT IS ENERGY……
Light –Dependent Reactions:
Energy Source:
_______________
Reactants:
Products:
_______________
Calvin Cycle:
Energy Source:
Reactants:
_________________
_________________
_______________
_________________
_______________
_________________
_______________
Products:
_________________
_______________
_________________
_______________
_________________
WHAT PROCESS IS PICTURED ABOVE? ___________________________________
I. Breathing versus Cellular Respiration
• _____________________________: physical process that allows animals and humans to come into
contact with gases in the air.
• _____________________________: chemical process that releases energy from organic compounds
(food), gradually converting it into energy that is stored in ATP molecules
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II. Chemical Pathways
1. What is the raw material used by cells to provide the energy your body needs to function?
2. What do cells synthesize from this raw material?
3. Cells do not BURN glucose, they slowly release energy from it and other food compounds through
several pathways (processes)
a. 1st pathway ______________________: releases only a small amount of energy (2 net ATP)
i. If oxygen________________, it will lead to two other pathways that release a lot of
energy: Krebs cycle & Electron Transport Chain
ii. If oxygen ____________________: glycolysis is followed by a different pathway:
Alcoholic Fermentation or Lactic Acid Fermentation
4. What does glycolysis mean literally?
5. What does aerobic mean? ___________________________________ what pathways after glycolysis
follow aerobic respiration? ____________________ & _______________________________________
6. What do we call Glycolysis followed by the Krebs Cycle and the Electron Transport Chain?
7. Write the chemical equation that shows the cellular respiration reaction:
8. Where does the glucose used in cellular respiration come from?
III. Glycolysis
9. Takes place in the ___________________________________________________________________
outside of the ________________________________.
10. Define cytosol:
____________________________________________________________________________________
____________________________________________________________________________________
11. Define cytoplasm:
____________________________________________________________________________________
____________________________________________________________________________________
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12. Glycolysis coverts _______________ with the help of ___ATP molecules and eventually releases
___ATP molecules; for a net gain of ___ ATP molecules.
13. Look at the diagram below, what else is produced during glycolysis?
2 ATP
used up
become
2 ADP
2 NADH
& 2 H+
produced
4 ATP produced
Net gain =
2 ATP
Steps of Glycolysis:
Step 1: breaks 1 molecule of glucose in half, producing 2 molecules of pyruvic acid (a 3-carbon
compound)
Step 2: 2 NAD+ ; electron carrier accepts 4 high-energy electrons transfers them to 2 NADH molecules
and 2 H+ thus passing the energy stored in the glucose
Step 3: 4 ADP added producing 4 ATP; net gain 2 ATP
Step 4: 2 remaining pyruvic acids enter Krebs Cycle in presence of oxygen; IF no oxygen another
pathway is followed
14. Glycolysis is a fast/ slow process.
15. Glycolysis alone ______________________ require oxygen.
16. What happens if a cell generates large amounts of ATP from glycolysis?
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IV. Anaerobic to Aerobic Respiration
17. When was oxygen added to Earth’s atmosphere? ___________________________________________
18. Why was this period known as the “oxygen catastrophe”?
V. Mitochondrion Structure
19. Mitochondrion has two separate membranes: ______________ and ____________ membrane.
20. Three compartments: ________________________________, _________________________, and
______________.
21. Label the inner membrane, outer membrane, intermembrane space, cristae space, and matrix on the
picture below:
22. What structure divides this organelle into three compartments? _______________________________
23. Where is the intermembrane space located?
24. How is the cristae space formed?
25. What is the matrix enclosed by? What stage takes place here?
26. Where is the Electron Transport Chain located?
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VI. Aerobic Respiration: The Krebs Cycle and Electron Transport Chain
27. Where is 90% of the unused chemical energy from glucose now stored?
28. How is this energy extracted?
The Krebs Cycle: 2nd stage of Cellular Respiration
29. Here ______________________________ is broken down into ______________________________.
30. What is the first compound formed? __________________________________________
31. What is another name for the Krebs Cycle? _____________________________________
Steps of the Krebs Cycle:
(1)
(2)
(3)
(4)
(5)
Pyruvic acid enters from glycolysis; One carbon removed = CO2 formed
NAD+ again changed to NADH
CoA joins remaining 2 carbons = Acetyl-CoA
Acetyl-CoA added to 4 carbons to form = Citric acid (6-C)
Citric acid broken down to 5-carbon, then 4 carbon; more CO2 released. Along the way more
NADH and FADH2 formed and one molecule of ATP also made
(6) 2 turns & 2 pyruvic acid (from glycolysis) yields:
10 NADH (2 from glycolysis)
2 FADH2
4 ATP (2 from glycolysis)
(7) Cycle starts anew
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VII. Uses for the products of the Krebs Cycle
32. ____________________________ is exhaled (waste product).
33. ________ can be used for cellular activities
34. High-energy electrons (stored in ________& __________) can be used to make huge amounts of ATP in
the ____________________ of oxygen.
VIII.
Electron Transport Chain
(1) Electrons from Krebs cycle are passed to electron transport chain by _________ & ___________
(2) At end of the chain an enzyme combines electrons from the electron chain with H + ions and
oxygen to form ______________
(3) Each time 2 high-energy electrons transport down the electron chain, their energy is used to
transport ______________across the membrane
(4) H+ ions build up in __________________________________ it is now ___________________
charged, other side of membrane __________________ charged
(5) Electrochemical gradient (chemiosmotic gradient) created for ____________________ to work
(6) ATP synthase converts ________ into ________
35. In __________________________, electron transport chain is a series of carrier proteins located in the
inner membrane of the mitochondrion
36. In __________________________, same chain only in the cell membrane.
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IX. The Total ATP production of Aerobic Cellular Respiration
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X. Anaerobic Respiration: Fermentation
37. This occurs after glycolysis when oxygen is ________________________, thus anaerobic process.
38. In this process cells convert NADH to ________ by passing high-energy electrons back to pyruvic acid.
39. Now _____________________ has NAD+ and can continue producing ATP.
40. What are the 2 types of fermentation?
____________________________________________________________________________________
XI. Alcoholic Fermentation
41. What types of organisms go through alcoholic fermentation?
42. Look at the equation below and list the products of alcoholic fermentation:
____________________________________________________________________________________
pyruvic acid + NADH  ethyl alcohol + CO2 + NAD+
XII. Lactic Acid Fermentation
43. Many cells convert accumulated pyruvic acid from gycolysis to lactic acid; lactic acid fermentation
regenerates NAD+ so glycolysis can continue.
44. Look at the equation below and list the products of lactic acid fermentation:
____________________________________________________________________________________
pyruvic acid + NADH  lactic acid + NAD+
45. When your body cannot supply enough oxygen to muscle tissues during exercise to make ATP, how is
energy production regenerated?
46. How do you get rid of the “BURN” sensation caused by the buildup of lactic acid in your body?
XIII.
Energy and Exercise
47. Initially body uses _______ which is already available in muscles; then new ATP made by
_______________________________ and ____________________________________.
48. ATP in muscles only lasts a _________ seconds.
49. ATP from lactic acid fermentation lasts about ____ seconds
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50. Exercise lasting longer than 90 seconds utilizes _________________________________ to generate a
continuous supply of ATP.
51. Body stores energy in muscles and tissues in the form of _____________________ (carbohydrate);
stores of glycogen usually lasts for ______________ minutes of activity, then the body starts to break
down other molecules like __________ for energy.
52. HOW LONG DO YOU NEED TO ACTIVE BEFORE YOU START TO BURN FAT?
XIV.
Aerobic vs. Anaerobic Respiration: A Comparison
53. Advantages of Aerobic Respiration:
a. ______________________________________________________________________________
b. ______________________________________________________________________________
54. Advantages of Anaerobic Respiration:
a. ______________________________________________________________________________
b. ______________________________________________________________________________
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XV. Relationship between Cellular Respiration and Photosynthesis
Equation for Cellular Respiration:
6O2 + C6H12O6  6CO2 + 6H2O + energy (ATP)
Equation for Photosynthesis:
6CO2 + 6H2O + energy (sunlight)  6O2 + C6H12O6
Photosynthesis
Cellular Respiration
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
LET’S REVIEW…
•
How many stages does cellular respiration have? ___________
•
What are the stages of cellular respiration?
____________________________________________________________________________________
Where does glycolysis take place?
____________________________________________________________________________________
Where does the Krebs cycle take place?
____________________________________________________________________________________
Where is the Electron Transport Chain located?
•
•
•
____________________________________________________________________________________
•
What do high-energy electrons help the cells build? _________________________________________
•
What are the stage(s) of anaerobic respiration?
____________________________________________________________________________________
What are the stage(s) of aerobic respiration?
•
____________________________________________________________________________________
•
What are the two types of fermentation?
____________________________________________________________________________________
•
Which fermentation process do humans use? ______________________________________________
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WORD BANK: Place the proper
letter (a-n) in each circle of the
flowchart. Every answer is used
just once.
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
l.
m.
n.
2 ATP
4 ATP
38 ATP
10 NADH
1 FADH2
Electron transport chain
Mitochondrion
Cytosol
Fermentation
Glycolysis
Glucose
2 Pyruvate molecules
Lactic acid
Kreb's Cycle
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