Question

One of the following correctly explains the function of ATP synthase enzyme in a cell.

• A. It uses energy to move ions against their concentration gradient by removing a phosphate group from ATP.
• B. It uses the power of ions moving against their concentration gradient to add a phosphate group to ADP.
• C. It uses the power of ions moving down their concentration gradient to add a phosphate group to ADP.
• D. It uses the power of ions moving against their concentration gradient to remove a phosphate group from ATP.
• E. It uses the power of ions moving down their concentration gradient to remove a phosphate group from ATP.

Answer 1

The correct option is C It uses the power of ions moving down their concentration gradient to add a phosphate group to ADP.

ATP synthase has two distinct components: a peripheral membrane protein called $F_1$, and $F_o$ which is integral to the membrane. $F_o$ has a proton pore through which protons down the concentration gradient and the proton concentration gradient serve as the energy source to drive the synthesis of ATP from ADP and inorganic phosphate on $F_1$ particle. This makes option C the correct answer.