What is activation energy and how do enzymes affect it?

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Multiple Choice

What is activation energy and how do enzymes affect it?

Activation energy is the energy barrier that reactants must overcome to reach the transition state of a reaction. It determines how fast a reaction can proceed at a given temperature. Enzymes speed things up by stabilizing the transition state and creating a favorable environment in the active site. This lowers the energy required to reach that transition state, so more molecules can get over the barrier and the reaction rate increases (the rate constant depends on Ea and rises when Ea is lowered). Importantly, enzymes do not change the amount of energy a reaction releases or absorb (the overall free energy change) nor do they change substrate concentration; they simply make it easier for reactants to reach the transition state and proceed to products.

Activation energy is the energy barrier that reactants must overcome to reach the transition state of a reaction. It determines how fast a reaction can proceed at a given temperature. Enzymes speed things up by stabilizing the transition state and creating a favorable environment in the active site. This lowers the energy required to reach that transition state, so more molecules can get over the barrier and the reaction rate increases (the rate constant depends on Ea and rises when Ea is lowered). Importantly, enzymes do not change the amount of energy a reaction releases or absorb (the overall free energy change) nor do they change substrate concentration; they simply make it easier for reactants to reach the transition state and proceed to products.

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