ap bio unit 3 pt 1

Question 1

What does the chemiosmotic process in chloroplasts involve?

Answer 1

establishment of a proton gradient

Question 2

In glycolysis, for each molecule of glucose oxidized to pyruvate

Answer 2

2 molecules of ATP are used and 4 molecules of ATP are produced.

Question 3

In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP?

Answer 3

energy released from movement of protons through ATP synthase

Question 4

Which statement describes the functioning of photosystem II?

Answer 4

The electron vacancies in P680 are filled by electrons derived from water.

Question 5

The primary role of oxygen in cellular respiration is to

Answer 5

act as an acceptor for electrons and hydrogen, forming water.

Question 6

During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level?

Answer 6

FADH2

Question 7

Which of the following is likely to lead to an increase in the concentration of ATP in a cell?

Answer 7

an increase in a cell’s catabolic activity

Question 8

What wavelength of light in the figure is most effective in driving photosynthesis?

Answer 8

420 mm

Question 9

Figure 10.1 shows the absorption spectrum for chlorophyll a and the action spectrum for
photosynthesis. Why are they different?

Answer 9

Other pigments absorb light in addition to chlorophyll a.

Question 10

The oxygen consumed during cellular respiration is involved directly in which process or event?

Answer 10

accepting electrons at the end of the electron transport chain

Question 11

In a plant cell, where are the ATP synthase complexes located?

Answer 11

thylakoid membrane & plasma membrane

Question 12

Where does the Calvin cycle take place?

Answer 12

stroma of the chloroplast

Question 13

Photorespiration lowers the efficiency of photosynthesis by preventing the formation of

Answer 13

3-phosphoglycerate molecules

Question 14

Which metabolic pathway is common to both cellular respiration and fermentation?

Answer 14

glycolysis

Question 15

Why are C4 plants able to photosynthesize with no apparent photorespiration?

Answer 15

They use PEP carboxylase to initially fix CO2 .

Question 16

What are the products of linear photophosphorylation?

Answer 16

ATP and NADPH

Question 17

The ATP made during glycolysis is generated by

Answer 17

substrate-level phosphorylation.

Question 18

The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction

Answer 18

loses electrons and loses energy.

Question 19

Which of the following is an example of potential rather than kinetic energy?

Answer 19

a food molecule made up of energy-rich macromolecules

Question 20

When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a hydrogen ion) the molecule becomes

Answer 20

reduced

Question 21

What is proton-motive force?

Answer 21

the transmembrane proton concentration gradient

Question 22

CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they

Answer 22

fix CO2 into organic acids during the night.

Question 23

A molecule that is phosphorylated

Answer 23

has an increased chemical reactivity; it is primed to do cellular work

Question 24

Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?

Answer 24

glycolysis

Question 25

In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of

Answer 25

ATP, CO2 , and ethanol (ethyl alcohol).

Question 26

The ATP made during fermentation is generated by which of the following?

Answer 26

substrate-level phosphorylation

Question 27

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1
hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did
the extra ATP molecules come from?

Answer 27

cyclic electron flow

Question 28

Where are the molecules of the electron transport chain found in plant cells?

Answer 28

thylakoid membranes of chloroplasts

Question 29

Generation of proton gradients across membranes occurs during

Answer 29

both photosynthesis and respiration.

Question 30

Which of the following sequences correctly represents the flow of electrons during photosynthesis?

H2O → NADPH → Calvin cycle
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Answer 30

H2O → NADPH → Calvin cycle

Question 31

Which of the following statements best describes the relationship between photosynthesis and
respiration?

Answer 31

Photosynthesis stores energy in complex organic molecules, while respiration
releases it.

Question 32

How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of
pyruvate?

Answer 32

2

Question 33

Synthesis of ATP by the chemiosmotic mechanism occurs during

Answer 33

both photosynthesis and respiration.

Question 34

Inside an active mitochondrion, most electrons follow which pathway?

Answer 34

citric acid cycle → NADH → electron transport chain → oxygen