In chemiosmosis, what is the most direct source of energy that is used to convert ADP + ᵢ to ATP?
A) energy released as electrons flow through the electron transport chain
B) energy released from substrate-level phosphorylation
C) energy released from movement of protons through ATP synthase, down their electrochemical gradient
D) energy released as electrons are transported across the inner mitochondrial membrane

Question

In chemiosmosis, what is the most direct source of energy that is used to convert ADP +  ᵢ to ATP?
A) energy released as electrons flow through the electron transport chain 
B) energy released from substrate-level phosphorylation 
C) energy released from movement of protons through ATP synthase, down their electrochemical gradient 
D) energy released as electrons are transported across the inner mitochondrial membrane

Quizplus · Accepted Answer

The most direct source of energy used to convert ADP to ATP in chemiosmosis is the movement of protons through ATP synthase down their electrochemical gradient. This occurs as a result of the proton motive force generated by the electron transport chain. Substrate-level phosphorylation is a separate mechanism that generates ATP through the transfer of a phosphate group from a substrate to ADP, but it is not directly involved in chemiosmosis. Similarly, while the transport of electrons across the inner mitochondrial membrane is a key step in the electron transport chain, it is not directly responsible for the conversion of ADP to ATP.

In Chemiosmosis, What Is the Most Direct Source of Energy