Ch. 11 notes

Ch. 11 notes - Ch. 11 Is a G protein = GTPase? Cell...

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Ch. 11 Is a G protein = GTPase? 18:23 Cell signaling Yeast cells 2 mating types = a and α a factor bind to specific receptor proteins a/α cell how? signal transduction pathway maybe first evolved in ancient prokaryotes and single-cell eukaryotes bacteria: quorum-sensing-concentration of signaling molecules allow bacteria to monitor the local density of cells coordinate behavior so they can carry out activities that are only productive when performed by a given number of cells in synchrony ex) formation of a biofilm – an aggregation of bacterial cells adhered to a surface Local and long-distance signaling Many types Direct contact (cell junctions, cell-cell recognition) Local regulators – influence cells in the vicinity Growth factors – compounds that stimulate nearby target cells to grow and divide (paracrine signaling) Synaptic signaling – an electrical signal along a nerve cell triggers the secretion of neurotransmitter molecules carrying a chemical signal diffuse across synapse trigger response in target cell Long distance signaling Plants and animals: hormones Animals: endocrine signaling – specialized cells release hormone molecules which travel via the circulatory system and reach target cells Ex) insulin Plants: plant growth regulators – hormones which travel in vessels but more often by moving through cells/diffusing as a gas
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Ex) ethylene Transmission of a signal through nervous system Preview Reception – target cell’s detection of a signaling molecule coming from outside the cell Transduction – convert the signal to a form that can bring about a specific cellular response Signal transduction pathway Relay molecules Response – any imaginable cellular activity Reception – signaling molecule binds to a receptor protein change shape Signaling molecule = ligand-molecule that specifically binds to another molecule and causes it to change shape Plasma membrane proteins = signal receptors = transmembrane G protein-coupled receptors (GPCR)
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This note was uploaded on 03/14/2012 for the course BISC 220 taught by Professor Mcclure during the Spring '09 term at USC.

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Ch. 11 notes - Ch. 11 Is a G protein = GTPase? Cell...

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