Photosystem II and the Cytochrome b6f Complex Photosynthesis (Part 4)

The video tutorial explains the function of photosystem II, focusing on the role of cytochrome B6F in electron transfer. It details the Q cycle, comparing it to the mitochondrial respiratory chain, and describes the sequential transfer of protons and electrons. The tutorial also covers the formation of a proton gradient used for ATP synthesis and the role of plastocyanin in electron transfer.

What is the primary function of Photosystem II in the electron transport chain?

• To split water molecules and release oxygen

• To transport protons across the membrane

• To synthesize glucose

• To generate ATP directly

Which component in Cytochrome B6F is responsible for transferring electrons from plastoquinone?

• ATP synthase

• Plastocyanin

• Rieske iron-sulfur center

• Cytochrome F

What is the role of the Rieske iron-sulfur center in Cytochrome B6F?

• It absorbs light energy

• It synthesizes ATP

• It transfers electrons from plastoquinone

• It pumps protons into the lumen

What role does plastocyanin play in the electron transport chain?

• It transfers electrons to Photosystem I

• It acts as a proton pump

• It splits water molecules

• It synthesizes ATP

How does the proton gradient in the thylakoid lumen contribute to photosynthesis?

• It directly produces glucose

• It powers ATP synthase to generate ATP

• It releases oxygen

• It absorbs light energy

What is a potential consequence of superoxide anion formation in the thylakoid?

• Stabilization of the thylakoid membrane

• Increased ATP production

• Damage to proteins and coenzymes

• Enhanced electron transport

Which enzyme helps mitigate the damage caused by superoxide anions?

• ATP synthase

• Superoxide dismutase

• Plastoquinone

• Cytochrome C

What happens to the electron carried by plastocyanin?

• It is stored as chemical energy

• It is transferred to Photosystem I

• It is lost as heat

• It is used to split water molecules

How is the iron in cytochrome F regenerated to its original state?

• By splitting water molecules

• By synthesizing ATP

• By transferring electrons to plastocyanin

• By absorbing light energy

What is the final electron acceptor in the electron transport chain of photosynthesis?

• Water

• Glucose

• NADP+

• Oxygen