Which statement is TRUE of enzyme catalysts?
A) They bind to substrates but are never covalently attached to substrate or product.
B) They increase the equilibrium constant for a reaction, thus favoring product formation.
C) They increase the stability of the product of a desired reaction by allowing ionizations, resonance, and isomerizations not normally available to substrates.
D) They lower the activation energy for the conversion of substrate to product.
E) To be effective, they must be present at the same concentration as their substrates.

Question

Quizplus · Accepted Answer

Enzyme catalysts lower the activation energy for the conversion of substrate to product, making it easier for the reaction to occur. The other options are incorrect: A is false because enzymes can be temporarily covalently attached to substrates or products during the reaction; B is false because enzymes do not affect the equilibrium constant of a reaction, only the rate at which it occurs; C is false because enzymes do not affect the stability of products, only the rate of their formation; and E is false because enzymes can be effective at very low concentrations relative to their substrates.

Which Statement Is TRUE of Enzyme Catalysts