Cellular Respiration Worksheet Answer Key by nuhman10


									Biol 12              Glucose Metabolism Worksheet                                                1

You should be able to:
a. Cite the overall equation for aerobic respiration and relate the reactants and products
to the three metabolic pathways of cellular respiration.
b. Associate the structure of the mitochondria with the Krebs cycle and respiratory chain.
c. Tell how many ATP are produced by each of the three pathways.
d. Discuss the function of the Krebs cycle as a metabolic mill.
Describe the process of anaerobic respiration, relating it to glycolysis and indicating its
advantages and drawbacks.

Review Questions:

1. The equation ADP + Pi  ATP is energy (requiring or releasing) requiring

2. When cells require energy for synthetic reactions, they ”spend”            ATP

                   1   2   3   4
3. In the pathway A B  C  D  E, the letters stand for                     reactants

and the numbers stand for             enzymes                 . Each and every reaction in

a cell requires an            enzyme                          . If this pathway represented

glycolysis, what molecule would E represent?          Pyruvic acid             The letter A in

relation to number 1 is a             substrate       , and the letter C in relation to

number 2 is a                 product                 .

4. The first pathway in glucose metabolism is         glycolysis              . The

transition reaction leads to the next pathway, called the     Kreb’s           cycle
or the citric acid cycle.

5. NAD carries                electrons                       to the          ETC

where most of the ATP of cellular respiration is formed.

6. Which pathway in question 4 contributes the most electrons to the respiratory chain

(the electron transport system)?             Kreb’s

7. When NAD accepts electrons from a substrate (while accepting hydrogen ions), it is

          reduced             . When NADH donates its electrons to the ETC, (and

therefore looses its Hydrogen ions) it becomes                oxidized

                              LEO GER
Biol 12                Glucose Metabolism Worksheet                                           2

8. The energy of oxidation released during the reactions of cellular respiration is used to

form a maximum of how many molecules of ATP?                  38

9. The oxygen we breathe in is carried by the blood to our cells, where it enters the

mitochondria. There it serves as the final acceptor for       electrons     .

10. The carbon dioxide given off by cellular respiration comes primarily from which

pathway?                 Citric acid cycle

11. In the diagram below, indicate the words energy required, energy released, breaking
a bond, and creating a bond.

          Left Side                          ATP                     Right Side

          E required                                                 E released
                                     +P               -P
          Creating a bond                                            Breaking a bond

12. Give the overall equation for aerobic cellular respiration. Indicate energy on the
correct side.

C6 H12O6 + 6 O2  6 H2O + 6 CO2 + 36-38 ATP

13. Label matrix, cristae, intermembrane space, inner membrane and outermembrane
on the drawing of the mitochondria below.

14. Which of the above structures would you associate with the Kreb’s cycle?        matrix

b. Which of the above structures would you associate with the ETC? inner membrane

c. Where does glycolysis take place?           The cytosol.
Biol 12                 Glucose Metabolism Worksheet                                            3



                                             Pyruvic Acid

          CO 2 + Acetyl CoA                                                       Lactic Acid

15. Match I, II, III, in the diagram above with these terms:

a. glycolysis   I

b. aerobic cellular respiration          I   , II

c. fermentation     I     ,        III

d. transition reaction.       II

16. Considering II, what happens to NADH following this reaction?      The NADH
enters the ETC and donates it’s electrons (becomes oxidized). The Energy is used to
drive chemiosmosis

What happens to the CO2 ? We exhale it.

What happens to the Acetyl CoA?                 The acetyl group enters Kreb’s cycle, the
CoA is recycled
17. Considering III: In yeast, the product for this reaction is not lactic acid; it is

ethanol and CO2                       . What happens to NAD+ following this reaction? - it
will be reused in another round of glycolysis.

18. Which of the molecules in this diagram have (has) six carbon atoms? glucose

Which have (has) three carbon atoms?                Pyruvic acid, + lactic acid

Which have (has) two carbon atoms?                          Acetyl CoA

19. Match I, II, III, with these terms:

oxygen not available III

6 ATP per glucose molecule II

2 ATP directly I

19. Glycolysis begins with                   glucose        and ends with         Pyruvate
Biol 12             Glucose Metabolism Worksheet                                          4

19. The number of ATP produced in glycolysis is        2

The number of ATP produced by means of 2 NADH                6

                                               Total   8

20. Fermentation is wasteful and harmful to the body.

a. Why wasteful?                Only 2 ATP per glucose (instead of 36-38)

b. Why harmful?         Lactic Acid is toxic

c. Under what conditions does a cell carry on fermentation?         When you run out of

21. The Krebs cycle begins and ends with               Oxaloacetic acid (OAA)     .

Calculate the number of ATP produced per glucose molecule

During the cycle        2

From 6 NADH             18

From 2 FADH2            4

          Total         24

22. A total of 38 ATP are produced per glucose molecule. Account for all of the ATP
a. as a result of glycolysis  8

b. as a result of Krebs cycle 24

c. as a result of Transition reaction   6

23. The respiratory chain (ETC) begins with            NADH or FADH2              and

ends with         O2 + 2H2  H2O               .

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