Chapter 11 cell signaling 11 05 2015 FIG 11 2 FIG 11 16 CONCENTRATE ON DIAGRAMS Mating factors in yeast 1 exchange of mating factors 2 mating 3 a new cell is formed slime molds use cyclic amp to call each other together communication junctions gap junctions plasmodesmata communication between plant cells cell cell recognition signaling in animal cells local signaling o synaptic signaling o paracrine signaling mast cells releasing histamine helper t cells sending out cytokines long distance signaling o endocrine hormonal signaling pancreas FIG 11 5 and 11 6 Hormone to set in motion to excite Signal transduction 1 reception signaling molecule ligand binds to receptor in plasma membrane receptor changes in some way 2 transduction relay molecules pass through in a signal transduction pathway 3 response activation of cellular response three responses to know 1 g protein coupled receptor FIG 11 7 proteins have certain shape with primary Secondary tertiary structures can be on or of GDP attached to G protein attaches to receptor and gdp is switched with gtp hooks up with inactive enzyme cellular response g protein leaves enzyme and gtp is broken back down into gdp Botulism stops g proteins 2 tyrosine kinase proteins kinase moves phosphate ligand binds to signaling molecules creating dimer dimer goes through phosphorylation to become full activated activates relay proteins release two diferent cellular responses many receptors have an amplification process 11 16 goes through relay process multiplies of molecule FIG 11 10 phosphorylation cascade Moving into final step of cellular response BOTH IMPORTANT IN 1 2 3 gated ion channels ions move into cell through gate opened by ligand ions in cell create cellular response gate closes when ligand released first messenger hormone that comes in and binds to receptor ATP changed into cAMP second messenger phosphodiesterase breaks down cAMP back into AMP to stop response FIG 11 13 FIG 11 14 Phospholipase C PIP either DAG or IP3 which is chosen depends on final signal given DAG diacyglycerol IP3 inositol trisphosphate second messenger Second messenger moves down and binds to gated channel that causes the release of calcium ions into the cell which will activate various proteins which in turn will active cellular responses FIG 11 15 Growth factors Phosphorylation cascade End up activating an inactive transcription factor that is already present in the cell Will turn on a gene by transcription factor then will so transcription and translation FIG 11 18 Not always one response A lot of diferent things can communicate with each other STEROID HORMONES Lipid soluble can go across cell membrane Receptor inside cell Form hormone receptor complex Goes into nucleus of cell Attaches to DNA and causes transcription and translation FIG 11 17 making microfilaments FIG 11 20 One cell dead one alive Apoptosis FIG 11 21 Death signaling molecules Cell forms blebs on its way out causes cell to die Reason we don t have webbed toes and fingers except Schaefer 11 05 2015 11 05 2015