Question

Enzymes speed up reactions by lowering the activation energy. What other value do they lower?

A. the free energy of products

b. it lowers all these values

c. the free energy of the transition

d. the free energy of the reactants

You add a drug that destroys the H+ gradient across the inner membrane of the mitochondria. What would happen to the rate of ATP production?

A. decrease

b. no change

c. increase

Answer 1

1) The transition state is a molecular state at which many events occur such as bond breakage, bond formation and charge development. When there is no catalyst the reaction requires more energy to reach the transition state and the energy required to reach transition state is the activation energy. Activation energy is an energy difference between ground state and transition state. The enzyme reduces this energy to accelerate the reaction, so transition state is achieved fast and lower activation energy. so the answer is option C.

2) H+ gradient across the inner membrane of mitochondria is required for the ATP formation. Because the proton gradient is required to operate the ATP synthase. If the gradient is not formed ATP synthase will not work. So the answer is option A (Decrease).