BIOL 111 Lecture Notes - Lecture 11: Autocrine Signalling, Signal Transduction, Paracrine Signalling
Document Summary
The signal transduction pathway is the series of steps converting signals from cell surface to cell response. Either cell junctions (plasmodesmata) or cell-cell recognition (glycoproteins) Paracrine signaling is where a cell secretes a signal to a neighboring cell. This lets the cells know if they need to grow/divide. (ex skin cells) Synaptic signaling is specific to nerve cells. Quorum sensing allows bacteria to sense local population density. Autocrine signaling acts on the same cell that secrets it. Three phases of the signal transduction pathway are reception, transduction, and response: reception: Signal molecules (ligands) are the first signals. These are large and polar and bind to receptor proteins on cell surface. This causes a conformation change that generates a signal. There are three plasma membrane receptors: g protein coupled receptors. These attach a phosphate to tyrosine and triggers multiple signal transduction pathways at once. Turns a monomer to a dimer: ligand-gated ion channel receptors.
