Question 1

Refer to the first image. Which statement best describes what is happening to the substrate and product concentrations over time in an enzyme-catalyzed reaction?

Accepted Answer

The substrate concentration decreases while the product concentration increases until equilibrium is reached, after which both remain constant.

Question 2

Based on the second image, which graph (a, b, or c) corresponds to a reaction with an equilibrium constant $$K_{eq} \u003c 1$$?

Accepted Answer

Graph b

Question 3

In the enzyme-substrate interaction depicted in the fifth image, which model is being illustrated?

Accepted Answer

Lock and key model

Question 4

Refer to the energy diagrams in the tenth image. What is the main effect of an enzyme on the reaction pathway?

Accepted Answer

It lowers the activation energy ($$E_A) $$without changing the overall free energy change ($$\Delta G).$$

Question 5

In the reaction coordinate diagram with two peaks (image 15), what do the two peaks represent?

Accepted Answer

Two transition states separated by a reaction intermediate

Question 6

Which of the following best describes the effect of an enzyme on the equilibrium position of a reaction?

Accepted Answer

It does not affect the equilibrium position; it only increases the rate at which equilibrium is reached.

Question 7

Which of the following is a potential disadvantage for an enzyme having too high of an affinity for its substrate?

Accepted Answer

The ES complex could end up in a large energy trough with a consequentially large $$E_A to $$the transition state.

Question 8

Which of the following statements about enzyme-catalyzed reactions is FALSE?

Accepted Answer

Enzymes push the reaction equilibrium toward product formation.

Question 9

Which of the following best describes catalysis by proximity?

Accepted Answer

Catalysis through increasing the concentration of substrates in the enzyme active site.

Question 10

Which of the following is NOT a way that enzymes increase rates of reactions?

Accepted Answer

Conformational changes in binding site slightly increases $$E_A.$$

Question 11

Which class of enzyme catalyzes the transfer of phosphate groups between molecules?

Accepted Answer

Transferase

Question 12

Which of the following is an indicator that a reaction is catalyzed by an oxidoreductase?

Accepted Answer

Loss of a hydrogen

Question 13

Which of the following best describes the function of a lyase enzyme?

Accepted Answer

To facilitate a reaction where two substrates form one product without the use of water.

Question 14

Which of the following is NOT one of the six internationally accepted classes of enzymes?

Accepted Answer

Polymerases

Question 15

Which of the following statements about enzyme cofactors is FALSE?

Accepted Answer

Metal ions can be prosthetic groups.

Question 16

Which of the following best applies to metal ion catalysis?

Accepted Answer

Both b & e

Question 17

Which of the following catalytic mechanisms proceeds via noncovalent interactions?

Accepted Answer

a, b & d

Question 18

Which of the following is true regarding the effect of an enzyme on the activation energy ($$E_A) $$and the equilibrium constant ($$K_{eq}) of a $$reaction?

Accepted Answer

Enzymes lower $$E_A$$ but do not change $$K_{eq}.$$

Protein Function and Enzyme Kinetics: Structured Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards