Question

What are the terms for the reactants in an enzyme catalyzed reaction?

Answer 1

Enzymes are the proteinaceous catalysts present in biological systems. They act on the reactants and form the products at an accelerated rate. The reactant for the enzymes can be any biomolecule or ligand which have structural compatibility with the enzyme. The enzymes are very specific in nature and are usually named after the reactant it acts upon.

Complete answer:
Enzymes are catalysts that act on chemical substances or reactants called the substrate. The substrate is a broader word having contextual meanings. In general, the substrate is the environment, base, or surface where the organisms reside.
The substrate is a widely used term, but it is mainly used to talk about biochemical functions.
In the general sense, a substrate is a chemical substance (i.e. its reactant) that is observed during a reaction. In a biochemical sense, this is the molecule with which the enzyme reacts.
The general scheme for the enzymatic reaction is –
Substrate(reactant) – acted upon by enzyme – product formation.
Hence, the term used for the reactants in an enzyme-catalyzed reaction is a substrate.

Note:
The enzyme binds with substrate molecules at the active site and forms the enzyme-substrate complex. After the complex is formed, conformational changes occur and the activation energy is reduced, thus the catalytic reaction proceeds, and the product is formed at an accelerated rate.