Activation energy is defined as which of the following?

Activation energy is defined as which of the following?

• A. A measure of disorder or randomness.
• B. Energy needed to get a reaction started.
• C. A substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics.
• D. Binds to the enzyme away from the active site altering the conformation of the enzyme so that its active site no longer functions.

Answer: (B)

Activation energy is the minimum amount of energy that reactants must absorb to reach the transition state and begin the chemical transformation. This energy barrier controls how fast a reaction can proceed, since only a fraction of collisions has enough energy to overcome it. Enzymes speed up reactions by providing an alternative pathway with a lower activation energy, making it easier for reactants to reach the transition state at a given temperature. The other ideas describe different concepts: energy related to disorder is entropy, a competitive inhibitor blocks the active site by mimicking the substrate, and a noncompetitive inhibitor binds away from the active site altering the enzyme's shape. Activation energy is specifically about the energy needed to start the reaction.

Activation energy is the minimum amount of energy that reactants must absorb to reach the transition state and begin the chemical transformation. This energy barrier controls how fast a reaction can proceed, since only a fraction of collisions has enough energy to overcome it. Enzymes speed up reactions by providing an alternative pathway with a lower activation energy, making it easier for reactants to reach the transition state at a given temperature. The other ideas describe different concepts: energy related to disorder is entropy, a competitive inhibitor blocks the active site by mimicking the substrate, and a noncompetitive inhibitor binds away from the active site altering the enzyme's shape. Activation energy is specifically about the energy needed to start the reaction.