BIO 311D Chapter Notes - Chapter 39.1: Guanylyl Cyclase, Etiolation, Signal Transduction
Document Summary
39. 1: signal transduction pathways link signal reception to response: example: a forgotten potato in the back corner of a kitchen cupboard, beginning: ghostly pale stems, short and stubby roots, unexpanded leaves, etiolation: morphological adaptations for growing in darkness. Would lose water faster with expanded leaves. No need for complicated root system because no need for water replacement. No need to waste energy making chlorophyll (no light) instead: allocation of energy to elongating stems. Allows shoots to break ground before nutrient reserves in tuber are exhausted: when a shoot reaches light, it experiences de-etiolation aka greening. Stem elongation slows leaves expand and roots elongate. Phosphorylation of amino acids alters protein"s hydrophobicity and activity (kinases) Protein phosphatases are enzymes that dephosphorylate proteins; they"re super important in switching off processes. Cell"s functioning depends on balance of activity of kinases and phosphatases transcriptional regulation: increases/decreases mrna synthesis for a specific enzyme.
