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

Question 1

Which of the following best describes the overall chemical equation for photosynthesis in plants?

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 2

Where in the chloroplast do the light-capturing reactions of photosynthesis take place?

Accepted Answer

Thylakoid membrane

Question 3

What is the primary role of chlorophyll pigments in photosynthesis?

Accepted Answer

Absorb light energy to excite electrons

Question 4

During the light reactions of photosynthesis, what is the fate of water ($$\mathrm{H}_2\mathrm{O}$$)?

Accepted Answer

It is oxidized to produce oxygen ($$\mathrm{O}_2)$$

Question 5

Which enzyme is responsible for carbon fixation in the Calvin cycle?

Accepted Answer

Rubisco (Ribulose-1,5-bisphosphate carboxylase/oxygenase)

Question 6

What are the main products of the light-capturing reactions that are used in the Calvin cycle?

Accepted Answer

ATP and NADPH

Question 7

Which of the following best explains why plants store excess glucose as starch?

Accepted Answer

Starch is insoluble and can be stored without affecting osmotic balance

Question 8

How are the processes of photosynthesis and cellular respiration related in plants?

Accepted Answer

Photosynthesis stores energy in organic molecules, while respiration releases it

Question 9

Which of the following statements about the Calvin cycle is correct?

Accepted Answer

It uses ATP and NADPH to reduce CO$$_2 to $$sugar

Question 10

A plant is exposed to a toxin that inhibits ATP synthase in the chloroplast. Which process would be directly affected?

Accepted Answer

Production of ATP during the light reactions

Question 11

Which of the following best describes the flow of electrons during the light reactions of photosynthesis?

Accepted Answer

From water to NADP$$^+$$ via photosystem II and photosystem I

Question 12

If a plant is placed in an environment with no light, which of the following processes will immediately stop?

Accepted Answer

Production of ATP and NADPH in the thylakoid membrane

Question 13

Which of the following is a correct comparison between ATP synthesis in mitochondria and chloroplasts?

Accepted Answer

Both use a proton gradient across a membrane to drive ATP synthase

Question 14

Which molecule is regenerated during the Calvin cycle to allow the cycle to continue?

Accepted Answer

Ribulose-1,5-bisphosphate (RuBP)

Question 15

A mutation prevents a plant from producing NADPH during the light reactions. What is the most immediate consequence for the Calvin cycle?

Accepted Answer

The reduction of 3-phosphoglycerate (3PGA) to glyceraldehyde-3-phosphate (G3P) would stop

Question 16

Which of the following best explains why plants need mitochondria in addition to chloroplasts?

Accepted Answer

Mitochondria allow plants to produce ATP from sugars when light is not available

Question 17

Which of the following is a direct product of the Calvin cycle that can be used to synthesize glucose and fructose?

Accepted Answer

Glyceraldehyde-3-phosphate (G3P)

Question 18

If a plant's thylakoid membranes were damaged, which process would be most directly affected?

Accepted Answer

Light-capturing reactions

Question 19

Which of the following statements about the fate of sugars produced in photosynthesis is correct?

Accepted Answer

They can be stored as starch or used to produce ATP via cellular respiration

Question 20

Which of the following best describes the role of the enzyme ATP synthase in photosynthesis?

Accepted Answer

It synthesizes ATP using the energy from a proton gradient across the thylakoid membrane

Chapter 10: Photosynthesis – The Process, Mechanisms, and Significance

Study Guide - Practice Questions