Which Statement is TRUE of Enzyme Catalysts

Question

Which statement is TRUE of enzyme catalysts?
A) Their catalytic activity is independent of pH.
B) They are generally equally active on D and L isomers of a given substrate.
C) They can increase the equilibrium constant for a given reaction by a thousand fold or more.
D) They can increase the reaction rate for a given reaction by a thousand-fold or more.
E) To be effective, they must be present at the same concentration as their substrate.

Accepted Answer

Enzyme catalysts can increase the reaction rate for a given reaction by a thousand-fold or more. Option A is incorrect as the activity of enzyme catalysts is highly pH-dependent. Option B is incorrect as enzymes show stereospecificity and are generally more active on one isomer than the other. Option C is incorrect as enzymes do not affect the equilibrium constant for a reaction, which is a thermodynamic property, and not affected by the presence of a catalyst. Option E is also incorrect as enzymes work at very low concentrations and are highly effective even at very low substrate concentrations.