Second messengers

Definition

Second messengers are intracellular signaling molecules released by the cell in response to exposure to extracellular signaling molecules. They help amplify and propagate the signal within the cell, leading to various cellular responses.

5 Must Know Facts For Your Next Test

1. Common second messengers include cAMP, IP3, and calcium ions.
2. Second messengers are crucial for signal transduction pathways.
3. They often activate protein kinases which then phosphorylate other proteins.
4. Second messengers can be rapidly synthesized and degraded, allowing for quick cellular responses.
5. Abnormalities in second messenger systems can lead to diseases such as cancer and diabetes.

Review Questions

• What is the role of second messengers in cell signaling?
• Name three common second messengers and their functions.
• How do second messengers contribute to the amplification of a signal?

Related terms

Signal Transduction: The process by which a chemical or physical signal is transmitted through a cell as a series of molecular events.

cAMP (Cyclic Adenosine Monophosphate): A common second messenger involved in many biological processes, including the regulation of metabolism.

Protein Kinase: An enzyme that modifies other proteins by chemically adding phosphate groups to them, often activated by second messengers.