Define the term 'cell signalling.'
Cell signalling - When cells communicate to each other via signal molecules.
- What helps cells detect hormones?
- How are cells able to detect that one hormone is different from another?
- On the cell surface membrane, there are receptors which detect for any hormones
- Receptors on the cell have a specific shape. They can only bind on to a specific hormone whose shape is complimentary to their own. The hormones' specific shape allows the receptors to tell them apart.
Describe how signalling molecules, such as a hormone, outside the cell carries out a response in the cell.
- Proteins in the cell membrane act as receptors for these signalling molecules.
- This means they have a specific shape that is complementary to the hormone they can detect and bind on to.
- The signalling molecule binds on to the complementary receptors.
- This triggers a response inside the cell.
HIV, which cause AIDs, can inffect humans because it can enter the cells of the immune system. Suggest how HIV can enter these cells.
HIV has a shape that can fit into one of the receptors on the cell surface, allowing it to enter and reproduce inside the cell.