Question

Q22). Which process in photosynthesis will be most directly compromised by inhibition of the cytochrome b6f complex?

A) proton pumping
B) carbon dioxide fixation
C) NADP+ reduction
D) water splitting

Answer 1

The inhibition of the cytochrome b6f complex in photosynthesis would directly impair proton pumping, which is vital for creating the electrochemical gradient used for ATP synthesis in the light-dependent reactions of photosynthesis.

Step-by-step explanation:

The process in photosynthesis that would be most directly compromised by inhibition of the cytochrome b6f complex is proton pumping (A). The cytochrome b6f complex plays a crucial role in the electron transport chain (ETC) of the light-dependent reactions in photosynthesis. It facilitates the transfer of electrons between photosystem II (PSII) and photosystem I (PSI), which is an essential step for the generation of a proton gradient across the thylakoid membrane.

This proton gradient is critical for ATP synthesis, as it drives ATP synthase to convert ADP to ATP, which is subsequently used in the light-independent reactions, also known as the Calvin cycle, to fix carbon dioxide into organic molecules. Inhibition of the cytochrome b6f complex would lead to a disruptment in the creation of this proton gradient and therefore impede ATP production, severely affecting the photosynthetic process.