$$6 \ \mathrm{CO}_2 + 6 \ \mathrm{H}_2O + \text{light energy} \rightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \ \mathrm{O}_2$$

Question 1

Which of the following best describes the overall chemical reaction for photosynthesis?

Accepted Answer

$$6 \ \mathrm{CO}_2 + 6 \ \mathrm{H}_2O + 	ext{light energy} ightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \ \mathrm{O}_2$$

Question 2

What is the primary function of the light-capturing reactions in photosynthesis?

Accepted Answer

To produce ATP and NADPH using energy from sunlight

Question 3

Which structure within the chloroplast is the site of the light-dependent reactions?

Accepted Answer

Thylakoid membrane

Question 4

Why do plants appear green to the human eye?

Accepted Answer

Chlorophyll reflects and transmits green light

Question 5

What is the main role of carotenoids in photosynthesis?

Accepted Answer

To absorb light energy and protect chlorophyll from damage

Question 6

Which enzyme catalyzes the fixation of carbon dioxide in the Calvin cycle?

Accepted Answer

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

Question 7

Photorespiration is considered wasteful because it:

Accepted Answer

Consumes oxygen and releases fixed carbon dioxide

Question 8

Which of the following best explains why C4 and CAM plants are more efficient in hot, dry environments?

Accepted Answer

They concentrate CO$$_2$$ near Rubisco, reducing photorespiration

Question 9

What is the immediate product of the Calvin cycle that can be used to synthesize glucose and other carbohydrates?

Accepted Answer

Glyceraldehyde-3-phosphate (G3P)

Question 10

Which process directly generates the proton-motive force used to synthesize ATP in the chloroplast?

Accepted Answer

Redox reactions in the thylakoid electron transport chain

Question 11

A plant is exposed to light that is only green in wavelength. What is the most likely outcome for its rate of photosynthesis?

Accepted Answer

Photosynthesis will decrease because chlorophyll reflects green light

Question 12

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

Accepted Answer

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

Question 13

What is the function of the cuticle on plant leaves?

Accepted Answer

To prevent water loss by evaporation

Question 14

Which of the following best describes the difference between cyclic and noncyclic electron flow in photosynthesis?

Accepted Answer

Cyclic electron flow produces only ATP, while noncyclic produces both ATP and NADPH

Question 15

Which of the following is a direct result of water splitting during the light reactions?

Accepted Answer

Oxygen is released as a by-product

Question 16

A mutation disables the function of ATP synthase in the chloroplast. What is the most immediate effect on the cell?

Accepted Answer

The cell cannot produce ATP during the light reactions

Question 17

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

Accepted Answer

Glucose

Question 18

Why is Rubisco considered the most important enzyme on Earth?

Accepted Answer

It catalyzes the fixation of atmospheric CO$$_2$$ into organic molecules

Question 19

In which cellular compartment does the synthesis of sucrose from G3P primarily occur?

Accepted Answer

Cytosol

Question 20

Which of the following statements about the fate of G3P produced in the Calvin cycle is correct?

Accepted Answer

It can be used to synthesize glucose, fructose, and starch

Photosynthesis: Mechanisms and Adaptations

Study Guide - Practice Questions