An agonist is a drug that will bind to the hormone receptor and inhibit it. T) True F) False
The correct answer and explanation is:
Correct Answer: False
Explanation (300 words):
An agonist is a drug or chemical that binds to a receptor and activates it, producing a biological response. It mimics the action of a naturally occurring substance, such as a hormone or neurotransmitter, by binding to its specific receptor and stimulating the same effect that the natural ligand would have.
In contrast, a drug that binds to a receptor but inhibits its activity is called an antagonist. Antagonists occupy the receptor but do not activate it. Instead, they block the receptor from being activated by agonists, whether they are drugs or natural substances like hormones.
For example, morphine is an opioid receptor agonist, meaning it binds to opioid receptors and triggers pain relief. On the other hand, naloxone is an opioid receptor antagonist, meaning it binds to the same receptors but blocks them, preventing or reversing the effect of opioids like morphine.
Agonists can be further classified as:
- Full agonists – activate the receptor to the maximum response (e.g., heroin or methadone at opioid receptors).
- Partial agonists – bind and activate receptors but produce a weaker response (e.g., buprenorphine).
- Inverse agonists – bind to the same receptor as an agonist but induce the opposite effect.
Understanding the difference between agonists and antagonists is essential in pharmacology and medicine, as it determines the therapeutic effect and potential side effects of medications.
Summary:
The statement “An agonist is a drug that will bind to the hormone receptor and inhibit it” is false. Agonists activate, not inhibit, receptors. It is antagonists that inhibit receptor activity by blocking or preventing the action of agonists or natural ligands.