Ligand
Definition
A ligand is a molecule that binds to another (usually larger) molecule. In cell communication, it's often the signal molecule that binds to a receptor.
Analogy
Think of a ligand like a key and the receptor as a lock. The key (ligand) fits into the lock (receptor), which then opens and triggers an action within the cell.
Related terms
Agonist: A substance which initiates a physiological response when combined with a receptor.
Antagonist: A substance that interferes with or inhibits the physiological action of another by competing for its receptor sites.
Hormone: Chemical messengers produced by glands in multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behavior.
"Ligand" appears in:
Study guides (4)
Practice Questions (4)
- Several receptors' production is triggered only when a significant amount of a ligand or substance is present. If an organism's experiences high levels of iron, it will produce __.
- A cell releases a ligand to other cells that are nearby or in close proximity. This type of cell signalling is called __.
- When the ligand or signaling molecule binds to a receptor protein and changes its shape, it is called __.
- A(n) __ is a transmembrane protein that opens or closes as it changes shape in response to a ligand, allowing or blocking the flow of specific ions.
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