Final answer:
Cell signaling is the process by which cells communicate with each other and coordinate their activities. It involves the release of signaling molecules by signaling cells, which bind to receptors on target cells and initiate a chain of events. There are three stages in cell signaling: reception, signal transduction, and cellular response.
Step-by-step explanation:
Cell signaling is the process by which cells communicate with each other and coordinate their activities. It involves the release of signaling molecules by signaling cells, which bind to receptors on target cells and initiate a chain of events. There are four categories of cell signaling: paracrine, endocrine, autocrine, and direct signaling. Paracrine signaling occurs over short distances, while endocrine signaling involves the release of hormones into the bloodstream for long-distance communication. Autocrine signaling occurs when a cell signals itself or nearby cells, and direct signaling occurs through gap junctions between neighboring cells.
Cell signaling involves three stages: reception, signal transduction, and cellular response. During reception, the signaling molecule binds to a receptor on the target cell's plasma membrane or inside the cell. This triggers a series of events known as signal transduction, where the signal is passed through the cell via a signaling pathway or cascade. In this process, molecules are often phosphorylated or small molecules called second messengers are used to transmit the signal. Finally, the cellular response occurs, which can include protein synthesis, changes in metabolism, cell growth, or cell death.