Enzymes

Review Questions

Which of the following is not true about enzymes:

  1. They increase ∆G of reactions
  2. They are usually made of amino acids
  3. They lower the activation energy of chemical reactions
  4. Each one is specific to the particular substrate(s) to which it binds

Hint:

A

An allosteric inhibitor does which of the following?

  1. Binds to an enzyme away from the active site and changes the conformation of the active site, increasing its affinity for substrate binding
  2. Binds to the active site and blocks it from binding substrate
  3. Binds to an enzyme away from the active site and changes the conformation of the active site, decreasing its affinity for the substrate
  4. Binds directly to the active site and mimics the substrate

Hint:

C

Which of the following analogies best describe the induced-fit model of enzyme-substrate binding?

  1. A hug between two people
  2. A key fitting into a lock
  3. A square peg fitting through the square hole and a round peg fitting through the round hole of a children’s toy
  4. The fitting together of two jigsaw puzzle pieces.

Hint:

A