Question

What is the chemical nature of the receptor?

Answer 1

In biochemistry and pharmacology, receptors are protein-based chemical structures that receive and transmit signals that can be integrated into biological systems. These signals are typically chemical messengers that bind to a receptor and cause a cellular/tissue response, such as a change in a cell's electrical activity.

Complete answer:
The receptor's action can be classified into three categories: signal relay, amplification, and integration. Relaying forwards the signal, amplification amplifies the effect of a single ligand, and integration incorporates the signal into another biochemical pathway.

The location of receptor proteins can be used to classify them. Ligand-gated ion channels, G protein-coupled receptors, and enzyme-linked hormone receptors are all examples of transmembrane receptors. Intracellular receptors, which include cytoplasmic and nuclear receptors, are those found within the cell.

A ligand is a small molecule that binds to a receptor and can be a protein, peptide (short protein), or another small molecule such as a neurotransmitter, hormone, pharmaceutical drug, toxin, calcium ion, or parts of a virus or microbe. An endogenous ligand is a substance produced by the body that binds to a specific receptor.

Thus, Receptors are protein molecules found inside or on the surface of a target cell that receives a chemical signal. Signalling cells emit chemical signals in the form of small, usually volatile, or soluble molecules known as ligands.

Note: A specific type of receptor is linked to specific cellular biochemical pathways that correspond to the signal. While most cells contain numerous receptors, each receptor will only bind to ligands of a specific structure. This is analogous to how locks will only accept keys with specific shapes. When a ligand binds to a specific receptor, it either activates or inhibits the receptor's associated biochemical pathway.