Intracellular mediators

Definition

Intracellular mediators, also known as second messengers, are molecules that transmit signals from receptors on the cell surface to target molecules inside the cell. They play a crucial role in amplifying and propagating cellular responses to external stimuli.

5 Must Know Facts For Your Next Test

1. Common intracellular mediators include cAMP, calcium ions (Ca2+), and inositol triphosphate (IP3).
2. They are part of signal transduction pathways, which help cells respond to extracellular signals.
3. Intracellular mediators often activate or inhibit enzymes and other proteins, leading to changes in cellular activity.
4. Second messengers can be quickly synthesized and degraded, allowing for rapid and transient signaling.
5. They are essential for various physiological processes such as muscle contraction, hormone release, and gene expression.

Review Questions

Related terms

Signal Transduction: The process by which a cell converts an extracellular signal into a response through a series of molecular events.

G-Protein Coupled Receptors (GPCRs): A large family of cell surface receptors that activate intracellular signaling pathways through G-proteins upon ligand binding.

Protein Kinase: An enzyme that modifies other proteins by chemically adding phosphate groups to them, playing a key role in many signaling pathways.