What is the relationship between enzymes and activation energy?

What is the relationship between enzymes and activation energy?

• A. They increase activation energy
• B. They have no effect on activation energy
• C. They decrease activation energy
• D. They create new products

Answer: (C)

Activation energy is the energy barrier that must be overcome for a chemical reaction to start. Enzymes act as biological catalysts by providing an alternative, lower-energy pathway for the reaction. They do this mainly by binding the substrates in their active site in the right orientation, stabilizing the transition state, and sometimes altering the local environment to favor the reaction. Because the barrier is lower, the rate constant increases and the reaction proceeds much faster at a given temperature. Importantly, enzymes don’t change the overall energy change of the reaction or create new products; they simply speed it up by lowering the activation energy.

Activation energy is the energy barrier that must be overcome for a chemical reaction to start. Enzymes act as biological catalysts by providing an alternative, lower-energy pathway for the reaction. They do this mainly by binding the substrates in their active site in the right orientation, stabilizing the transition state, and sometimes altering the local environment to favor the reaction. Because the barrier is lower, the rate constant increases and the reaction proceeds much faster at a given temperature. Importantly, enzymes don’t change the overall energy change of the reaction or create new products; they simply speed it up by lowering the activation energy.