Question 1

Which of the following best explains how the electrochemical gradient required for ATP synthesis is generated during cellular respiration?

Accepted Answer

By the active transport of protons from the mitochondrial matrix into the intermembrane space, powered by the free energy released from electron transfer along the electron transport chain

Question 2

During oxidative phosphorylation, which molecule acts as the final electron acceptor in the electron transport chain?

Accepted Answer

O$$_2$$

Question 3

Which of the following correctly ranks the redox potentials of Complex II, FADH$$_2$$, Complex I, and NADH from highest to lowest?

Accepted Answer

Complex II \u003e FADH$$_2$$ \u003e Complex I \u003e NADH

Question 4

Which statement best describes the relationship between photosynthesis and cellular respiration?

Accepted Answer

Photosynthesis stores energy in organic molecules, while cellular respiration releases energy from organic molecules.

Question 5

What is the primary function of the Calvin cycle in photosynthesis?

Accepted Answer

To fix inorganic carbon dioxide into organic molecules using ATP and NADPH

Question 6

A plant is exposed to only green light. What is the most likely effect on its rate of photosynthesis, and why?

Accepted Answer

The rate will decrease because chlorophyll reflects green light rather than absorbing it.

Question 7

Which of the following best describes the role of ATP synthase in both mitochondria and chloroplasts?

Accepted Answer

It synthesizes ATP by allowing protons to flow down their electrochemical gradient across a membrane.

Question 8

If a mutation prevents Rubisco from functioning in a plant cell, which process would be directly affected?

Accepted Answer

The fixation of carbon dioxide in the Calvin cycle

Question 9

Which of the following is a key difference between NADH and NADPH in cellular metabolism?

Accepted Answer

NADH is used primarily in catabolic reactions, while NADPH is used in anabolic reactions such as the Calvin cycle.

Question 10

A patient is diagnosed with a mitochondrial disorder that impairs Complex I of the electron transport chain. Which of the following would most likely be observed?

Accepted Answer

Decreased ATP production due to impaired NADH oxidation

Question 11

Which of the following best explains why photosynthesis is considered a nonspontaneous process?

Accepted Answer

It requires the input of light energy to drive the unfavorable movement of electrons from water to NADP$$^+.$$

Question 12

In the context of energy storage and distribution in plants, which statement is correct?

Accepted Answer

Sucrose is synthesized for transport to cells in need of energy, while starch is stored as a long-term energy reserve.

Question 13

Which of the following best describes the function of the thylakoid membrane in chloroplasts?

Accepted Answer

It houses the photosystems and electron transport chain components necessary for the light-dependent reactions.

Question 14

A scientist measures the absorption spectrum of chlorophyll a and finds peaks in the blue and red regions. What is the most likely explanation for the green color of leaves?

Accepted Answer

Chlorophyll a reflects green light, which is not absorbed.

Question 15

Which of the following equations correctly represents the overall process of photosynthesis?

Accepted Answer

$$6 \mathrm{CO}_2 + 6 \mathrm{H}_2\mathrm{O} + 	ext{light energy} ightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2$$

Question 16

If a plant's chloroplasts are unable to produce ATP and NADPH, which of the following processes would be directly affected?

Accepted Answer

The Calvin cycle would be unable to fix carbon dioxide.

Question 17

Which of the following best explains why FADH$$_2$$ donates electrons to Complex II rather than Complex I in the mitochondrial electron transport chain?

Accepted Answer

FADH$$_2$$ has a higher redox potential than Complex I, so it cannot transfer electrons to it.

Question 18

A plant cell is placed in the dark for an extended period. Which of the following is most likely to occur?

Accepted Answer

The light-dependent reactions will stop, leading to decreased ATP and NADPH production, which in turn slows the Calvin cycle.

Cellular Respiration and Photosynthesis: Mechanisms of Energy Conversion in Cells

Guida di studio - Domande di pratica

Study guide - Flashcard