Ch 8-2

Question 1

What is the primary function of the light reactions?

Answer 1

To convert solar energy into ATP and NADPH.

Question 2

Where do light-dependent reactions occur?

Answer 2

In the thylakoid membrane.

Question 3

What is chlorophyll a’s role in photosynthesis?

Answer 3

It is the main light-capturing pigment.

Question 4

What colors of light does chlorophyll a absorb?

Answer 4

Violet-blue and red.

Question 5

What role do carotenoids play in photosynthesis?

Answer 5

They are accessory pigments that provide photoprotection.

Question 6

It becomes excited and moves to a higher energy level.

Answer 6

What happens to an electron when a pigment absorbs light?

Question 7

What are the two photosystems involved in photosynthesis?

Answer 7

Photosystem II (PSII) and Photosystem I (PSI).

Question 8

What does the electron transport chain (ETC) do in photosynthesis?

Answer 8

It transports electrons between photosystems and aids in ATP production.

Question 9

What molecule splits to provide electrons for the light reactions?

Answer 9

Water (H₂O).

Question 10

What is the function of the proton gradient in photosynthesis?

Answer 10

It drives ATP synthesis through chemiosmosis.

Question 11

What is P680 in Photosystem II?

Answer 11

The reaction-center chlorophyll molecule.

Question 12

What does NADP+ reductase do?

Answer 12

Catalyzes the formation of NADPH.

Question 13

What by-products are generated during the light reactions?

Answer 13

Oxygen and hydrogen ions.

Question 14

How is the energy for ATP production created in photosynthesis?

Answer 14

Through the flow of protons across the thylakoid membrane.

Question 15

What are the final products of the light reactions?

Answer 15

ATP and NADPH.

Question 16

Which pigment is the main light-capturing molecule in photosynthesis?
A) Chlorophyll a
B) Chlorophyll b
C) Carotenoids
D) Xanthophyll

Answer 16

A) Chlorophyll a

Question 17

What is the source of the electrons used in Photosystem II?

A) NADPH
B) Water
C) Carbon dioxide
D) Oxygen

Answer 17

B) Water

Question 18

Which photosystem is responsible for ATP production?
A) Photosystem I
B) Photosystem II
C) Photosystem III
D) Calvin Cycle

Answer 18

B) Photosystem II

Question 19

What is the function of carotenoids in photosynthesis?
A) Absorb red light
B) Store energy
C) Provide photoprotection
D) Capture green light

Answer 19

C) Provide photoprotection

Question 20

What process involves the pumping of protons into the thylakoid space?
A) Calvin Cycle
B) Glycolysis
C) Chemiosmosis
D) Respiration

Answer 20

C) Chemiosmosis

Question 21

How are electrons replaced in Photosystem II?
A) By splitting water
B) Through NADPH
C) By splitting oxygen
D) Through ATP synthesis

Answer 21

A) By splitting water

Question 22

Which molecule carries electrons from Photosystem I?
A) NADH
B) ATP
C) NADP+
D) FADH₂

Answer 22

C) NADP+

Question 23

What pigment reflects green light, making plants appear green?
A) Chlorophyll a
B) Chlorophyll b
C) Carotenoids
D) Anthocyanin

Answer 23

A) Chlorophyll a

Question 24

The proton gradient created by electron transport is used to:
A) Split water molecules
B) Pump electrons into the stroma
C) Drive ATP synthesis
D) Release carbon dioxide

Answer 24

C) Drive ATP synthesis

Question 25

Where do electrons go after being energized by light in Photosystem II? A) Photosystem I B) Calvin Cycle C) Mitochondria D) Chloroplast stroma

Answer 25

A) Photosystem I

Question 26

Which wavelength does Photosystem I absorb best? A) 680 nm B) 700 nm C) 500 nm D) 450 nm

Answer 26

B) 700 nm

Question 27

What is the role of NADPH in the Calvin Cycle? A) Supplies carbon B) Provides electrons and hydrogen C) Releases oxygen D) Absorbs light

Answer 27

B) Provides electrons and hydrogen

Question 28

What is produced by the light reactions and used in the Calvin Cycle? A) NADP+ and H₂O B) ATP and NADPH C) CO₂ and glucose D) Oxygen and water

Answer 28

B) ATP and NADPH

Question 29

Which complex uses chemiosmosis to produce ATP? A) Photosystem I B) Cytochrome complex C) ATP synthase D) Calvin Cycle

Answer 29

C) ATP synthase

Question 30

What molecule acts as the final electron acceptor in the light reactions? A) NADP+ B) ATP C) Oxygen D) Carbon dioxide

Answer 30

A) NADP+

Question 31

True or False: Photosystem I generates ATP.

Answer 31

False (Photosystem II is primarily responsible for ATP generation.)

Question 32

True or False: The Calvin Cycle occurs during the light-dependent reactions

Answer 32

False (It occurs during the light-independent reactions.)

Question 33

True or False: Chlorophyll absorbs all colors of light.

Answer 33

False (It reflects green light.)

Question 34

True or False: Water splitting in Photosystem II releases oxygen as a by-product.

Answer 34

True

Question 35

True or False: Carotenoids help protect the chloroplast by absorbing excess light.

Answer 35

T

Question 36

True or False: NADP+ is reduced to NADPH in Photosystem I.

Answer 36

T

Question 37

True or False: Chemiosmosis is the process of using a proton gradient to drive ATP synthesis.

Answer 37

T

Question 38

True or False: ATP synthase is located in the thylakoid membrane.

Answer 38

T

Question 39

True or False: P700 is associated with Photosystem II.

Answer 39

False (It is associated with Photosystem I.)

Question 40

True or False: ATP and NADPH produced in the light reactions are used in the Calvin Cycle.

Answer 40

T

Question 41

True or False: Only Photosystem II contains chlorophyll molecules

Answer 41

False (Both Photosystem I and II contain chlorophyll.)

Question 42

True or False: Electrons are passed from Photosystem I to Photosystem II.

Answer 42

False (Electrons are passed from Photosystem II to Photosystem I.)

Question 43

True or False: The thylakoid space becomes acidic during light reactions due to the proton gradient.

Answer 43

T

Question 44

True or False: ATP is produced by cyclic electron flow in the light reactions.

Answer 44

T

Question 45

True or False: Photosystem II is responsible for producing NADPH.

Answer 45

False (Photosystem I produces NADPH.)