Question

The production of ATP by means of oxidative phosphorylation takes place during

I. Glycolysis
II. Krebs cycle

III. Chemiosmosis

IV. Electron transport chain

• A. I only
• B. II only
• C. III only
• D. III and IV only
• E. I, II and III

Answer 1

The correct option is D III and IV only

During oxidative phosphorylation, electrons are transferred from electron donors to electron acceptors such as oxygen, in redox reactions. These redox reactions release energy, which is used to form ATP. Oxidative phosphorylation happens in two steps: the electron transport chain and chemiosmosis.

In the electron transport chain, electrons are passed from one molecule to another, and energy released in these electron transfers is used to form an electrochemical gradient. In chemiosmosis, the energy stored in the gradient is used to make ATP.

So, the correct answer is option D.