Question

multiple choice question
what are enzymes?
proteins that bind to the active site of a catalyst
molecules that are used by cells for long - term energy storage.
molecules that are used by cells to supply energy cyclically.
proteins or rna molecules that act as catalysts.

Explanation:

Enzymes are biological catalysts. Most enzymes are proteins, and some are RNA molecules called ribozymes. They speed - up chemical reactions in living organisms. The first option is incorrect as enzymes are not just proteins that bind to a catalyst's active site. Molecules for long - term energy storage are typically fats, not enzymes. Molecules for cyclic energy supply are often ATP, not enzymes.

Answer:

Proteins or RNA molecules that act as catalysts.