Chapter 13 Biosignaling
Chapter 13 Biosignaling
table13-1 Some Signals to Which Cells Respond Antigens Cell surface glycoproteins/oligosaccharides Developmental signals Extracellular matrix components Growth factors Hormones Light Mechanical touch Neurotransmitters Odorants Pheromones Tastants
(a) Specificity Signal molecule fits binding site on its complementary receptor other signals do not fit. Re eceptor Effect
(b) Amplification When enzymes activate Signal enzymes, the number of affected molecules increases geometrically in an enzyme cascade Enzyme 1 Enzyme 2 2 2 E enzyme 333333333
Signal (c) Desensitization/Adaptation Receptor activation triggers a feedback circuit that shuts off the receptor or removes AReceptor it from the cell surface Response