Which of the following statements is incorrect about enzymes?
a. they do not get used up in a reaction
b. the higher the concentration of the substrate (reactant), the slower the reaction will happen.
c. they increase the speed of the reaction
d. enzymes are protein

The answer is B. The higher the concentration of substrate, the FASTER a reaction happens (since there are more opportunities for molecules to collide in a way that favours the reaction), so B is an incorrect statement.

The other three options describe correct features of catalysts and/or enzymes (which are considered “biological catalysts”).

C) to ensure each new cell has an exact copy of the dna

The correct answer is a