Question

In a chemical reaction, the reactant that is broken down into products by binding to an enzyme is known as

• A. An active site
• B. A substrate
• C. A competitive inhibitor
• D. An allosteric site
• E. A non-competitive inhibitor

Answer 1

The correct option is B A substrate

A. Active site is a cavity present on the enzyme to which substrate binds and is converted to end product.

B. Substrate is the raw substance or reactant molecule that binds to active site of the enzyme and is converted into a product.

C. A competitive inhibitor competes with the substrate for binding to the active site of the enzyme because of its structural similarity with the substrate and this leads to decline in activity of enzyme.

D. Allosteric site is a site other than the active site present on the enzyme to which a molecule (known as modulator) can bind and either enhances or inhibit the activity of enzyme.

E. A non-competitive inhibitor bind to a site other than active site of the enzyme i.e. allosteric site and causes a change in the confirmation of the enzyme. This causes inhibition of binding of substrate to the enzyme and thus, enzyme activity is decreased.

So, the correct answer is 'A substrate'.