Receptors as Proteins with Binding Sites for Specific Signalling Chemicals
- Receptors are highly specific, meaning they only bind to particular molecules, called ligands.
- This specificity ensures that cells respond accurately to the right signals.
Definition
Receptor
A receptor is a protein that detects and responds to specific signals. They bind to signalling molecules(ligands) to initiate a cellular response.
Definition
Ligand
A ligand is a molecule that binds to a specific site on a receptor protein.
- Imagine you’re in a crowded room, and someone calls your name.
- You immediately turn to see who it is.
- This is similar to how cells communicate: they "listen" for specific signals using receptors.
Receptors
- Receptors are proteins found either:
- On the cell membrane (for ligands that cannot pass through the membrane, like hydrophilic molecules).
- Inside the cell (for ligands that are hydrophobic and can diffuse through the membrane, like steroid hormones).
- Receptors have specific binding sites that fit the structure of their ligand like a lock and key.
- This specificity ensures that only the correct ligand binds to its receptor, triggering the appropriate cellular response.
