Cell signalling is the communication between cells by means of chemicals for co-ordination between cells.
There are three main types of cell signalling:
- The receptor acts as an ion channel
- The receptor activates a G-protein
- The receptor acts as an enzyme
Although there are three types of cell signalling the basics remain the same.
A signal molecule (this could be a hormone) attaches to a receptor molecule in the plasma membrane (a protein or glycoprotein) . If the two have a complimentary shape, (the signal molecule fits the receptor molecule, like a lock and key) this will bring about a response in the cell. Each signal molecule has a specific receptor, this is how the cell decides which reaction or response is appropriate.
The receptor acts as an ion channel
In this method the signal molecule attaches to a receptor in this case a channel protein this changes the shape of the channel opening it and allowing ions into the cell. This brings about a response.
The receptor activates a G-protein
In this the signal molecule attaches to the receptor in the plasma membrane, this activates a G-protein inside the cell. This in turn activates an enzyme which brings about a reaction inside the cell.
The receptor acts as an enzyme
In this third type of cell signalling the receptor is an enzyme in 2 parts. The signal molecule slots into both parts of the receptor, creating one active enzyme. This enzyme brings about a reaction inside the cell.