BIOL 1001 Lecture : Lecture Topic 9
Document Summary
Local signaling through direct cytoplasmic connections (gap junctions, plasmodesmata) or through contact of surface molecules (cell-cell recognition in animals). In animals, a signaling cell releases messenger molecules into the interstitial fluid and these local regulators influence nearby cells. A nerve cell releases neurotransmitter molecules into the narrow synapse separating it from its target cell. In hormonal or endocrine signaling in animals, the circulatory system transports hormones throughout the body to reach target cells with appropriate receptors. Transmission of electrical and chemical signaling through the nervous system. Reception of a chemical signal by binding to a receptor protein either inside the cell or on its surface. A signaling molecule acts as a ligand, which specifically binds to a receptor protein and usually induces a change in the receptor protein"s shape. Binding of the appropriate extracellular signaling molecule activates the receptor, which binds to and activates a specific. G protein located on the cytoplasmic side of the membrane.
