This is a molecule found on or inside a cell. Receptors serve as docking stations for other molecules. That molecule could be a hormone such as insulin. It could be a chemical messenger such as dopamine. It could be a medicine or part of virus. When that molecule bumps into the receptor, it fits like a key in a lock. That joining triggers the receptor to change its shape. That shape change will in turn alter some part of a cell’s activity. Scientists trying to make new medicines will often design chemicals to fit specific receptors — and hopefully treat a disease or medical condition.
Receptors can be located in a cell’s membrane. They allow the cell to receive communications from outside. There are also receptors on the membrane surrounding the nucleus — the part of the cell that contains its genetic instructions. And there are some receptors that float inside a cell, catching molecules there. These internal receptors can receive signals from hormones or other chemicals that can change how a cell’s genetic instruction manual is used.
In a sentence
Tiny particles can fight viruses by hooking on to receptors on the invaders’ coats, squeezing them together until the germ pops like a balloon.