Name:                                                                                .                 2003 11 18

 

Read questions carefully. Attempt all questions as no marks will be deducted for incorrect responses.

The value of each question is one mark unless otherwise specified.     TOTAL   20

 

1.         A waste product of aerobic respiration and of alcoholic fermentation is . . .

A. carbon dioxide (CO₂)          C. ATP

B. NAD⁺                                             D. oxygen gas (O₂)

 

2. Cytoplasmic NAD⁺ is recycled in aerobic respiration at which stage?

             

A.     the conversion of pyruvate to Acetyl CoA

B.      the splitting of the 6-carbon sugar into two molecules of 3-carbon sugar

C.     the reduction of pyruvate

D.     the transfer of electrons from cytoplasmic NADH through a shuttle to the mitochondrial electron transport chain

3.         When pyruvate is converted to acetyl CoA ___________.

                   

A. CO₂ and Coenzyme A are formed

 

B. CO₂ and NADH are formed

 

C. CO₂ and NADH are consumed

 

D. NAD⁺ is regenerated

 

4.         The efficiency of aerobic respiration is approximately . . .

A. 10%            B. 20%            C. 2%              D. 40%

 

5.         How many ATPs are produced by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen?

                   

            A. 6 ATP         B. 2 ATP         C. 36 ATP       D. 4 ATP (2 in glycolysis, 2 in Krebs cycle)

 

6.         In respiration, which one of the following does the electron transport chain (or its components) NOT do directly?

                   

A. Carry electrons

B. Phosphorylate ADP to make ATP

C. Regenerate (oxidized) FAD

D. Form a proton gradient

 

7.         During oxidative phosphorylation in eukaryotic cells, ATP synthase catalyzes the phosphorylation of ADP to form ATP.

 The energy needed for this endergonic reaction comes from

 

A. the movement of hydrogen ions from the intermembrane space to the mitochondrial matrix.

B. the oxidation of NADH and FADH₂.

C. the movement of NADH from the cytoplasm to the mitochondria

D. the fermentation of pyruvate to form lactic acid

 

8.         The direct energy source that drives ATP synthesis during cellular respiration in the mitochondrion is

 

A.        the oxidation of carbohydrates

B.         the flow of electrons from NADH to oxygen

C.        the reduction of oxygen to water

D.        the difference in hydrogen ion concentration across the cristae of the mitochondrion

E.         ATP hydrolysis

 

9.         Alcoholic fermentation:

 

            A.        requires the presence of oxygen

            B.         results in the complete breakdown of glucose into CO₂ and H₂O

            C.        occurs inside the mitochondria

            D.        recycles the NAD⁺ needed in glycolysis

            E.         releases oxygen as a byproduct

 

10.       Which of the following statements is true about the Krebs cycle

            and the Calvin cycle?

 

A.        They both result in a net production of ATP and NADH.

B.         They both require a net input of ATP.

C.        They both result in a release of oxygen.

D.        They both take place within the cytoplasm.

E.         They both are carried out by enzymes located within the interior liquid compartment of an organelle.

 

11.       When reaction centres absorb energy from sunlight,       .

 

A. sugar phosphates are formed

B. RuBP accepts electrons

C. electrons are ejected and transferred to acceptor molecules

D. protons are moved into the thylakoid space

 

12.      Which sequence correctly portrays the flow of electrons during photosynthesis?

 

A. NADPH  Þ  oxygen  Þ  carbon dioxide

B. water   Þ  NADPH  Þ   Calvin cycle

C. water  Þ  NADH  Þ  ATP

D. water  Þ photosystem I   Þ  photosystem II

 

12(D’oh!).       The oxygen atoms released from the splitting of water are incorporated into     .

 

A. oxygen gas                           C. carbohydrates

B. water                                   D. NADPH

 

13. Photorespiration is a problem for plants because                .

 

A. it prevents cellular respiration

B. it stops photons from entering the leaf

C. it takes away half the carbon potential

D. it causes the plant to lose water

 

14.       The CO₂ reduction pathway that separates carbon fixation from the Calvin cycle temporally (in time) is                 .

 

A. the Calvin cycle                    C. C4 pathway

B. CAM pathway                      D. both B and C are correct

 

 

15.       What happens during the process called photorespiration?

 

        A. The light-dependent reactions cease to function and photosynthesis stops

        B. Plants carry on photosynthesis in the dark

        C. O₂ interferes with the light-independent reactions and slows photosynthesis

        D. CO₂ inhibits the light-independent reactions of photosynthesis

 

16.       How many G3P molecules can be made in a C4 plant from 48 photons?

A. two  (total of six carbons)     B. three            C. four             D. six               E. eight

 

17.       The product of the photolysis of water is:

 

            A.        electrons, water, and hydrogen ions

            B.         electrons, water, and ATP

            C.        electrons, water, and oxygen

            D.        electrons, oxygen, and hydrogen ions

            E.         hydrogen and oxygen

 

18.       Which of the following statements best describes photosynthesis?

 

            A.        Glucose is broken down to release CO₂ and energy

            B.         CO₂ from the atmosphere is used to make glucose and ATP is formed

            C.        CO₂, water, and solar energy are used to produce glucose

            D.        ATP, O₂ and CO₂ are used to make glucose

            E.         Chlorophyll is converted into glucose by solar radiation

 

19.       To synthesize one molecule of heptose, a seven-carbon carbohydrate, in a C3 plant,   X   molecules of water must be split during the light reactions, and   Y  molecules of ATP consumed in the Calvin cycle.

 

                        X                     Y        

 

            A.        6                      3

            B.         12                    6

            C.        7                      21

            D.        14                    21 (two water for every carbon, three ATP for every carbon)

            E.         14                    14

 

20.       Which of the following statements best represents the relationships between the light reactions and the    Calvin cycle?

 

A.        The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP⁺ to the light reactions.

B.         The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions.

C.        The light reactions supply the Calvin cycle with CO₂ to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP.

D.        The light reactions provide the Calvin cycle with oxygen for electron flow, and   the Calvin cycle provides the light reactions with water to split.

E.         The light reaction occurs during the day, and the Calvin cycle occurs during the night.