Question

A molecule that enters the body from an external source and alters its normal functions is a(an) A molecule that enters the body from an external source and alters its normal functions is a(an) agonist. drug. antagonist. steroid. hormone.

Answer 1

Answer:

Antagonist

Explanation:

Antagonist refers to molecule that enter the body and block actions. They are like ligands that attache to receptors but don't activate the receptors. But the decrease or reduce the biological activities or actions of other drugs in the body. They block biological functions , hence they are refer to as blockers.