Question

The production of pH gradient during oxidative metabolism of glucose takes place during

• A. Glycolysis
• B. Anaerobic respiration
• C. Krebs cycle
• D. Electron transport chain
• E. None of the above

Answer 1

The correct option is D Electron transport chain

Electron transport chain is a series of complexes (proteins and organic molecules) transports electrons from the donor to acceptors via redox reactions. As electrons are passed down the chain, they move from a higher to a lower energy level, releasing energy. Some of the energy is used to pump $H^{+}$ ions, moving them out of the matrix and into the intermembrane space. This pumping establishes an electrochemical gradient (increasing $H^{+}$ cause a change in pH). The transport chain builds a proton gradient across the inner mitochondrial membrane, with a higher concentration of $H^{+}$ in the intermembrane space and a lower concentration in the matrix. This gradient represents a stored form of energy, and it can be used to make $ATP.$

so, the answer is 'Electron transport chain.'