Receptors are proteins located on the surface of cells that are responsible for receiving signals like hormones or neurotransmitters and transmitting them into the cell.
Inhibitors can block the activity of receptors by competing with the natural ligand or by binding to a different site on the receptor and altering its shape or function. This can result in a decrease in the activation of the receptor, leading to a reduction in downstream signalling and physiological effects.
Agonists can activate receptors by mimicking the effects of the natural ligand, by enhancing the effects of the natural ligand, or by binding to a different site on the receptor and inducing a conformational change that leads to receptor activation.
Both inhibitors and agonists are important tools in pharmacology and are often used in drug development to target specific receptors and modulate their activity for therapeutic purposes. They can also be used in research.