Ch 8-2 Flashcards
What is the primary function of the light reactions?
To convert solar energy into ATP and NADPH.
Where do light-dependent reactions occur?
In the thylakoid membrane.
What is chlorophyll a’s role in photosynthesis?
It is the main light-capturing pigment.
What colors of light does chlorophyll a absorb?
Violet-blue and red.
What role do carotenoids play in photosynthesis?
They are accessory pigments that provide photoprotection.
It becomes excited and moves to a higher energy level.
What happens to an electron when a pigment absorbs light?
What are the two photosystems involved in photosynthesis?
Photosystem II (PSII) and Photosystem I (PSI).
What does the electron transport chain (ETC) do in photosynthesis?
It transports electrons between photosystems and aids in ATP production.
What molecule splits to provide electrons for the light reactions?
Water (H₂O).
What is the function of the proton gradient in photosynthesis?
It drives ATP synthesis through chemiosmosis.
What is P680 in Photosystem II?
The reaction-center chlorophyll molecule.
What does NADP+ reductase do?
Catalyzes the formation of NADPH.
What by-products are generated during the light reactions?
Oxygen and hydrogen ions.
How is the energy for ATP production created in photosynthesis?
Through the flow of protons across the thylakoid membrane.
What are the final products of the light reactions?
ATP and NADPH.
Which pigment is the main light-capturing molecule in photosynthesis?
A) Chlorophyll a
B) Chlorophyll b
C) Carotenoids
D) Xanthophyll
A) Chlorophyll a
What is the source of the electrons used in Photosystem II?
A) NADPH
B) Water
C) Carbon dioxide
D) Oxygen
B) Water
Which photosystem is responsible for ATP production?
A) Photosystem I
B) Photosystem II
C) Photosystem III
D) Calvin Cycle
B) Photosystem II
What is the function of carotenoids in photosynthesis?
A) Absorb red light
B) Store energy
C) Provide photoprotection
D) Capture green light
C) Provide photoprotection
What process involves the pumping of protons into the thylakoid space?
A) Calvin Cycle
B) Glycolysis
C) Chemiosmosis
D) Respiration
C) Chemiosmosis
How are electrons replaced in Photosystem II?
A) By splitting water
B) Through NADPH
C) By splitting oxygen
D) Through ATP synthesis
A) By splitting water
Which molecule carries electrons from Photosystem I?
A) NADH
B) ATP
C) NADP+
D) FADH₂
C) NADP+
What pigment reflects green light, making plants appear green?
A) Chlorophyll a
B) Chlorophyll b
C) Carotenoids
D) Anthocyanin
A) Chlorophyll a
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
C) Drive ATP synthesis
Where do electrons go after being energized by light in Photosystem II?
A) Photosystem I
B) Calvin Cycle
C) Mitochondria
D) Chloroplast stroma
A) Photosystem I
Which wavelength does Photosystem I absorb best?
A) 680 nm
B) 700 nm
C) 500 nm
D) 450 nm
B) 700 nm
What is the role of NADPH in the Calvin Cycle?
A) Supplies carbon
B) Provides electrons and hydrogen
C) Releases oxygen
D) Absorbs light
B) Provides electrons and hydrogen
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
B) ATP and NADPH
Which complex uses chemiosmosis to produce ATP?
A) Photosystem I
B) Cytochrome complex
C) ATP synthase
D) Calvin Cycle
C) ATP synthase
What molecule acts as the final electron acceptor in the light reactions?
A) NADP+
B) ATP
C) Oxygen
D) Carbon dioxide
A) NADP+
True or False: Photosystem I generates ATP.
False (Photosystem II is primarily responsible for ATP generation.)
True or False: The Calvin Cycle occurs during the light-dependent reactions
False (It occurs during the light-independent reactions.)
True or False: Chlorophyll absorbs all colors of light.
False (It reflects green light.)
True or False: Water splitting in Photosystem II releases oxygen as a by-product.
True
True or False: Carotenoids help protect the chloroplast by absorbing excess light.
T
True or False: NADP+ is reduced to NADPH in Photosystem I.
T
True or False: Chemiosmosis is the process of using a proton gradient to drive ATP synthesis.
T
True or False: ATP synthase is located in the thylakoid membrane.
T
True or False: P700 is associated with Photosystem II.
False (It is associated with Photosystem I.)
True or False: ATP and NADPH produced in the light reactions are used in the Calvin Cycle.
T
True or False: Only Photosystem II contains chlorophyll molecules
False (Both Photosystem I and II contain chlorophyll.)
True or False: Electrons are passed from Photosystem I to Photosystem II.
False (Electrons are passed from Photosystem II to Photosystem I.)
True or False: The thylakoid space becomes acidic during light reactions due to the proton gradient.
T
True or False: ATP is produced by cyclic electron flow in the light reactions.
T
True or False: Photosystem II is responsible for producing NADPH.
False (Photosystem I produces NADPH.)
