Question

the reactants of a chemical reaction that fit in the active site of the enzyme.
reusable
substrate
lactose
how do enzymes speed up chemical reactions?

Explanation:

To solve this, we analyze each option:

• "Reusable" describes a property of enzymes, not the reactants fitting the active site.
• "Substrate" is defined as the reactants in a chemical reaction that bind to the active site of an enzyme.
• "Lactose" is a specific sugar (a substrate for lactase), but it's a specific example, not the general term for reactants fitting enzyme active sites.
• "How do enzymes speed up chemical reactions?" is a question, not a term for the reactants.

Answer:

B. Substrate