Question

Which of the following sites is/are the location(s) of ATP generation through oxidative phosphorylation in Escherichia coli?
 

• A. Inner membrane only
• B. Outer membrane only
• C. Both outer membrane and inner membrane
• D. Mesosome

Hint:

In bacteria, oxidative phosphorylation occurs at the inner membrane, where the electron transport chain and ATP synthase are located. Mesosomes also play a role in increasing the surface area for energy production.

Answer 1

The Correct Option is A, D

In {Escherichia coli}, oxidative phosphorylation is the process by which ATP is generated as a result of the electron transport chain (ETC) and chemiosmosis. This occurs specifically at the inner membrane and in some cases at the mesosomes, which are specialized regions of the plasma membrane that help facilitate energy production. 
- Option (A): The inner membrane of {Escherichia coli} contains the necessary enzymes for the electron transport chain and ATP synthase, where oxidative phosphorylation takes place. Thus, the inner membrane is the primary site for ATP generation via oxidative phosphorylation. Hence, statement (A) is correct.
- Option (B): The outer membrane of {Escherichia coli} does not contain the machinery required for oxidative phosphorylation. Therefore, statement (B) is incorrect.
- Option (C): While the inner membrane is the main site of ATP generation, the outer membrane is not involved in this process. Therefore, statement (C) is incorrect.
- Option (D): The mesosome, a folded region of the bacterial plasma membrane, is involved in the process of oxidative phosphorylation in some bacteria, including {Escherichia coli}. It plays a role in increasing the surface area for energy production. Therefore, statement (D) is also correct.
Thus, the correct answer is (A) Inner membrane only and (D) Mesosome, as both these sites are involved in ATP generation in {Escherichia coli}.