Q: Which of the following correctly represents the overall chemical equation for oxygenic photosynthesis in land plants?

$6CO_2 + 6H_2O + \text{sunlight energy} \rightarrow C_6H_{12}O_6 + 6O_2$

Question 1

Which of the following correctly represents the overall chemical equation for oxygenic photosynthesis in land plants?

Accepted Answer

$6CO_2 + 6H_2O + 	ext{sunlight energy} ightarrow C_6H_{12}O_6 + 6O_2$

Question 2

During the light-dependent reactions of photosynthesis, what is the primary function of chlorophyll a?

Accepted Answer

To act directly in converting light energy to chemical energy

Question 3

Which color of light is LEAST effective for photosynthesis in green plants, and why?

Accepted Answer

Green, because it is mostly reflected by chlorophyll

Question 4

What is the relationship between the energy of a photon and its wavelength?

Accepted Answer

Energy is inversely proportional to wavelength

Question 5

Which process in photosynthesis is most similar to oxidative phosphorylation in cellular respiration?

Accepted Answer

Photophosphorylation during the light-dependent reactions

Question 6

In the light-dependent reactions, what is the source of electrons that replenish photosystem II after it loses electrons?

Accepted Answer

Splitting of water molecules ($2H_2O \rightarrow 4H^+ + 4e^- + O_2$)

Question 7

Which two products of the light-dependent reactions are required for the Calvin cycle?

Accepted Answer

ATP and NADPH

Question 8

What is the role of the antenna complex in a photosystem?

Accepted Answer

To gather photons and transfer the captured light energy to the reaction center

Question 9

Why is oxygen produced as a waste product during photosynthesis?

Accepted Answer

Because water is split to provide electrons for photosystem II

Question 10

Which statement best describes the difference between cyclic and noncyclic photophosphorylation?

Accepted Answer

Cyclic photophosphorylation produces only ATP, while noncyclic produces both ATP and NADPH

Question 11

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

Accepted Answer

Ribulose bisphosphate carboxylase/oxygenase (rubisco)

Question 12

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

Accepted Answer

Glyceraldehyde-3-phosphate (G3P)

Question 13

How are the processes of photosynthesis and cellular respiration connected in the energy cycle of the biosphere?

Accepted Answer

Photosynthesis uses the products of respiration as substrates, and respiration uses the products of photosynthesis as substrates

Question 14

A mutation disables the function of NADP$^+$ reductase in a plant cell. Which process would be directly affected?

Accepted Answer

Reduction of NADP$^+$ to NADPH during the light-dependent reactions

Question 15

Which of the following best explains why plants appear green?

Accepted Answer

Chlorophyll reflects green wavelengths of light

Question 16

If a plant is exposed only to green light, what would you expect to happen to its rate of photosynthesis?

Accepted Answer

It would decrease significantly because green light is mostly reflected

Question 17

Which molecule acts as the final electron acceptor in the light-dependent reactions of photosynthesis?

Accepted Answer

NADP$^+$

Question 18

A scientist discovers a new photosynthetic organism that uses only photosystem I. Which product would this organism be able to produce via photophosphorylation?

Accepted Answer

ATP only

Question 19

Which of the following is a major transport sugar in plants, formed from the immediate product of the Calvin cycle?

Accepted Answer

Sucrose

Question 20

Which statement best describes chemiosmosis in the context of photosynthesis?

Accepted Answer

It is the process by which a proton gradient across the thylakoid membrane drives ATP synthesis

Photosynthesis: Structure, Stages, and Overview

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