BIOL 1101 Chapter Notes - Chapter 9: G Protein–Coupled Receptor, Transmembrane Protein, Paracrine Signalling
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Signaling cells are the speci c cells within adrenal glands. Signaling molecule is the hormone adrenaline released by these cells. Adrenaline carried in bloodstream interacts with receptor proteins located on surface of responding cells like those of the heart: example 2: bacteria. Bacteria can take up dna from environment and incorporate it into own genome. Rate of dna uptake by pneumococcal (bacterial) cells increased sharply once bacterial population reached certain density > dna can communicate information to one another through release of a small peptide. Discovered a peptide (consisting of 17 amino acids) that is synthesized and released by bacterial cells + a receptor for this peptide. Binding of peptide to receptor causes bacterium to express generous required for. Bacteria at low density= peptide at too low a concentration to bind to the receptor. Increase in population density= increase of concentration of peptide= high enough to bind to enough receptors to cause cells to turn on genes needed for.