Question 1

Which of the following is a common strategy by which enzyme catalysis occurs?

Accepted Answer

Increasing the probability of product formation.

Question 2

Which of the following is NOT one of the four main types of enzyme catalysis mechanisms?

Accepted Answer

Hydrolytic catalysis.

Question 3

In general acid-base catalysis, what role does the enzyme play?

Accepted Answer

It donates or accepts protons to facilitate the reaction.

Question 4

Which of the following best describes covalent catalysis?

Accepted Answer

The enzyme forms a temporary covalent bond with the substrate.

Question 5

A person ingests a toxin that inhibits general acid-base catalysis in their body. Which of the following processes would be most directly affected?

Accepted Answer

Transfer of protons during enzyme-catalyzed reactions.

Question 6

Which of the following statements about enzyme catalysis is TRUE?

Accepted Answer

Enzymes can lower the activation energy by stabilizing the transition state.

Question 7

Which of the following is an example of specific acid-base catalysis?

Accepted Answer

A water molecule donates a proton to the substrate.

Question 8

Which of the following best explains why enzymes do not alter the equilibrium constant ($K_{eq}$) of a reaction?

Accepted Answer

Enzymes only affect the rate of reaction, not the overall energy difference between reactants and products.

Question 9

Which of the following is a distinguishing feature of general acid-base catalysis compared to specific acid-base catalysis?

Accepted Answer

General acid-base catalysis involves amino acid side chains donating or accepting protons.

Question 10

Which of the following is an example of electrostatic catalysis?

Accepted Answer

An enzyme stabilizes a developing negative charge on a transition state using a positively charged side chain.

Question 11

A mutation in an enzyme replaces a histidine residue with alanine in the active site. Which catalytic mechanism is most likely to be disrupted?

Accepted Answer

General acid-base catalysis.

Question 12

Which of the following best describes the role of the transition state in enzyme catalysis?

Accepted Answer

It is the highest energy state along the reaction pathway.

Question 13

Which of the following is a correct statement about the catalytic mechanism of serine proteases?

Accepted Answer

They use both covalent and general acid-base catalysis.

Question 14

Which of the following is a direct result of enzyme catalysis in a biological system?

Accepted Answer

Increased rate of product formation.

Question 15

Which of the following mechanisms is most likely to be involved if an enzyme stabilizes the negative charge on an intermediate using a lysine side chain?

Accepted Answer

Electrostatic catalysis.

Enzyme Catalysis: Mechanisms and Acid-Base Catalysis

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