What Makes an Enzyme a Catalyst

Question

What makes an enzyme a catalyst?
A) its ability to change shape to fit the substrate
B) it speeds up a chemical reaction but can only be used once
C) it speeds up a chemical reaction but becomes changed by the reaction
D) it speeds up a chemical reaction but is not changed by the reaction
E) its amino acids

Accepted Answer

An enzyme is a catalyst because it speeds up a chemical reaction without being changed by the reaction. This means that the enzyme can be used repeatedly to catalyze the same reaction, making it an efficient and effective catalyst. While enzymes can change shape to fit their substrate (A), they are not one-time-use catalysts (B) and they may undergo changes during the reaction, but are ultimately not permanently changed (C). The amino acids that make up an enzyme are important for its structure and function, but they alone do not make it a catalyst (E).