Question

Choose the correct answers from the alternatives given :
The direct energy source that drives ATP synthesis during oxidative phosphorylation is

• A. a difference of ${}^H+$ concentration on opposite sides of the inner mitochondrial membrane
• B. the affinity of oxygen for electrons
• C. oxidation of glucose and other organic compounds
• D. endergonic flow of electrons down the electron transport chain

Answer 1

The correct option is A a difference of ${}^H+$ concentration on opposite sides of the inner mitochondrial membrane

• In mitochondria the ETS is used for the transport of electrons and hydronium ions from inner mitochondrial membrane to the inter membrane matrix of mitochondria.
• Due to this the concentration of hydronium ions increases in the intermembrane matrix.
• The ATP synthase complex which is present in the inner membrane of the mitochrondria are used for the synthesis of ATP.
• The complex is used to transport hydronium ions from the intermembrane matrix down its concentration gradient
• For every 2 hydronium ions transported through the complex one molecule of ATP is generated.
• Therefore the transport of the H+ ions due the difference in the concentration provides direct energy for the formation of ATP.
• Therefore the correct answer is option 'a difference of H+ concentration on opposite sides of the inner mitochondrial membrane'.