Chapter 5 Flashcards
(20 cards)
What are the light-dependent reactions in photosynthesis?
Reactions that occur in the thylakoid membrane of the chloroplast, generating ATP and NADPH.
What initiates the light-dependent reactions?
Photosystem II absorbs a photon of light in the antenna complex.
What happens to P680 when it absorbs light?
An electron moves from the ground state to an excited state, oxidizing P680.
What is produced as a waste product of water splitting during light-dependent reactions?
1/2 O2.
What is the role of plastoquinone (PQ) in the light-dependent reactions?
Transfers electrons to the cytochrome complex, helping generate a proton gradient.
How is ATP synthesized during the light-dependent reactions?
H+ ions are pumped through ATP synthase from the thylakoid lumen to the stroma, converting ADP + Pi to ATP.
What is photophosphorylation?
The process of making ATP using light energy during the light-dependent reactions.
What is the final electron acceptor in the light-dependent reactions?
NADP+.
What is produced alongside NADPH during the light-dependent reactions?
G3P (glyceraldehyde 3-phosphate).
What are the three mechanisms that form a proton gradient across the thylakoid membrane?
- Protons taken into the lumen by redox reactions of PQ
- Protons added due to water splitting inside the lumen
- Protons removed from the stroma to make NADPH.
What is the Calvin Cycle?
The process where CO2 is converted into sugar via 11 enzyme-catalyzed reactions in the stroma.
What is photorespiration?
An unfavorable process that decreases sugar production by photosynthesis.
What environmental conditions lead to photorespiration in C3 plants?
Hot, dry environments where stomata close to conserve water.
What does rubisco catalyze in photorespiration?
The oxidation of RuBP instead of its carboxylation to PGA.
What is the primary energy source for photosynthesis?
Light energy from the sun.
What is the final electron acceptor in cellular respiration?
Oxygen (forms H2O).
Where does ATP accumulate in photosynthesis?
Thylakoid stroma.
Fill in the blank: The primary energy source for cellular respiration is _______.
Glucose.
True or False: The Calvin Cycle is also known as C3 photosynthesis.
True.
List the three phases of the Calvin Cycle.
- Carbon Fixation
- Reduction Reactions
- RuBP Regeneration.
