Question 1

Where in the chloroplast would you find the pigment that gives it a green color?

Accepted Answer

The thylakoid membrane

Question 2

Which of the following best describes the main function of the light-dependent reactions of photosynthesis?

Accepted Answer

To convert solar energy into chemical energy in the form of ATP and NADPH

Question 3

What is the immediate source of electrons for the reduction of NADP$$^+ to $$NADPH in the light reactions?

Accepted Answer

Ferredoxin

Question 4

Which of the following is NOT involved in cyclic electron flow during photosynthesis?

Accepted Answer

PSII

Question 5

What is the role of the oxygen evolving complex (OEC) in PSII?

Accepted Answer

It oxidizes water to provide electrons to chlorophyll a

Question 6

Which sequence correctly represents the flow of electrons in linear electron flow?

Accepted Answer

Water → PSII → Plastoquinone → Cytochrome b6f → Plastocyanin → PSI → Ferredoxin → NADP$$^+$$

Question 7

What is the primary function of cytochrome b6f in the thylakoid membrane?

Accepted Answer

To transfer electrons from plastoquinone to plastocyanin and pump protons into the lumen

Question 8

Which of the following best explains why ATP synthase is able to produce ATP during the light reactions?

Accepted Answer

The flow of H$$^+$$ ions down their electrochemical gradient through ATP synthase provides the energy for phosphorylation of ADP

Question 9

Which mobile electron carrier is water-insoluble and operates within the thylakoid membrane?

Accepted Answer

Plastoquinone

Question 10

If a mutation prevented the function of ferredoxin-NADP$$^+$$ reductase, which of the following would be directly affected?

Accepted Answer

The production of NADPH

Question 11

Which of the following statements about the differences between PSI and PSII is correct?

Accepted Answer

PSII receives electrons from water, while PSI receives electrons from plastocyanin

Question 12

Which process is responsible for the release of oxygen gas during photosynthesis?

Accepted Answer

The oxidation of water by the oxygen evolving complex in PSII

Question 13

Which of the following would most likely occur if the thylakoid membrane became permeable to protons (H$$^+$$)?

Accepted Answer

ATP synthesis would decrease due to loss of the electrochemical gradient

Question 14

Which of the following best describes the difference between cyclic and linear electron flow?

Accepted Answer

Cyclic flow produces only ATP, while linear flow produces both ATP and NADPH

Question 15

A plant is exposed to light, but its PSII is chemically inhibited. Which of the following would you expect to occur?

Accepted Answer

Oxygen evolution would stop

Question 16

Which of the following is the correct equation for the photophosphorylation reaction catalyzed by ATP synthase?

Accepted Answer

$$\mathrm{ADP} + \mathrm{P_i} \rightarrow \mathrm{ATP}$$

Question 17

Which of the following best explains why the production of ATP and NADPH is roughly equal during the light reactions?

Accepted Answer

Both photosystems operate simultaneously, transferring electrons from water to NADP$$^+$$ and generating a proton gradient

Question 18

Which of the following is a direct consequence of the accumulation of H$$^+$$ ions in the thylakoid lumen?

Accepted Answer

The creation of an electrochemical gradient that drives ATP synthesis

Question 19

Which of the following statements about the role of mobile electron carriers in the light reactions is correct?

Accepted Answer

Plastoquinone transfers electrons from PSII to cytochrome b6f

Light-Dependent Reactions of Photosynthesis: Structure, Function, and Mechanisms

Guida di studio - Domande di pratica