Question

Our body responds to changes in the environment through receptors.

Name any two types of receptors and state their functions.

Answer 1

Receptors are mainly of two types:

• The intracellular receptors (or cytoplasmic receptors). They are present in the cytosolic side of a cell and the ligand binding to the receptor to pass through the plasma membrane of the cell to bind to the receptors and enable cell signalling to occur. All steroid hormone receptors and the receptor for the thyroid hormone are intracellular receptors.
• The other type of receptors are the cell surface receptors. The ligand receptors in such cases are embedded on the cell surface. One type of cell surface receptors are the ligand-gated ion channels e.g the voltage-sensitive sodium channels present on the surface of neurons.