Science
Signal transduction.
Definition
Signal transduction is the process by which a cell converts an external signal (like a hormone or neurotransmitter) into a cellular response. A signaling molecule binds to a receptor, triggering a cascade of molecular events inside the cell that ultimately changes cell behavior.
How it works · 5 phases
Step by step.
- A signaling molecule (ligand) binds to a specific receptor on the cell surface.
- The receptor changes shape, activating intracellular relay proteins.
- A cascade of phosphorylation events amplifies the signal through the cell.
- The amplified signal activates transcription factors or enzymes that produce the cellular response.
- The response is terminated when the signaling molecule is removed or degraded.
Examples
Real-world.
- 1 Adrenaline binding to heart muscle receptors to increase heart rate
- 2 Insulin binding to receptors triggering glucose uptake into cells
- 3 Growth factors activating cell division pathways