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

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

Question 1

Which of the following best describes the overall purpose of photosynthesis in plants?

Accepted Answer

Conversion of light energy into chemical energy and its subsequent use in the synthesis of organic compounds.

Question 2

What is the primary function of the light-dependent reactions of photosynthesis?

Accepted Answer

To generate ATP and NADPH using light energy.

Question 3

Which molecule is directly produced by the photolysis of water during photosynthesis?

Accepted Answer

Oxygen

Question 4

Why do plants not simply transport ATP from the chloroplasts to non-photosynthetic tissues instead of synthesizing sucrose?

Accepted Answer

ATP is too unstable to be transported over long distances in the plant.

Question 5

Which enzyme catalyzes the carboxylation step in the Calvin cycle?

Accepted Answer

Rubisco (ribulose bisphosphate carboxylase/oxygenase)

Question 6

What is the main product of the Calvin cycle that is used for the synthesis of starch and sucrose?

Accepted Answer

Glyceraldehyde-3-phosphate (G3P)

Question 7

Which of the following best explains why chlorophyll is able to absorb light efficiently?

Accepted Answer

The presence of a porphyrin ring with a central Mg ion alters electron distribution, aiding light absorption.

Question 8

Which photosystem is primarily responsible for the oxidation of water and the release of oxygen?

Accepted Answer

Photosystem II (PSII)

Question 9

What is the correct sequence of events in the light-dependent reactions of photosynthesis?

Accepted Answer

Light harvesting → Electron transport and proton pumping → ATP synthesis

Question 10

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 11

Which pigment is primarily responsible for absorbing light at 680 nm in the chloroplast?

Accepted Answer

Chlorophyll a in Photosystem II

Question 12

What is the fate of the electrons excited in the reaction center chlorophyll during the light reactions?

Accepted Answer

They are transferred to an electron acceptor and eventually reduce NADP+ to NADPH.

Question 13

Which of the following best explains why the Calvin cycle is considered 'light-independent'?

Accepted Answer

It uses ATP and NADPH produced by the light-dependent reactions to fix carbon dioxide.

Question 14

A plant is exposed to light that only emits wavelengths above 700 nm. Which process will be most directly affected?

Accepted Answer

Photoexcitation in Photosystem II

Question 15

Which of the following is NOT a product of the light-dependent reactions of photosynthesis?

Accepted Answer

Glucose

Question 16

During the Calvin cycle, which molecule is regenerated to allow the cycle to continue?

Accepted Answer

Ribulose bisphosphate (RuBP)

Question 17

Which of the following best describes the role of the proton gradient in the thylakoid lumen?

Accepted Answer

It drives the synthesis of ATP via ATP synthase.

Question 18

If a plant's chlorophyll molecules were unable to transfer excited electrons to the electron transport chain, what would be the most immediate consequence?

Accepted Answer

No ATP or NADPH would be produced in the light-dependent reactions.

Question 19

Which of the following statements about the movement of carbohydrates in plants is correct?

Accepted Answer

Carbohydrates are synthesized in the leaves and transported to non-photosynthetic tissues for energy.

Question 20

Which chemical is converted to oxygen during photosynthesis?

Accepted Answer

Water

Photosynthesis: Mechanisms and Cellular Context

Study Guide - Practice Questions

Study Guide - Flashcards