BIOL 200 Lecture Notes - Lecture 26: Decoy, Proinsulin, Hydrolysis
25 Jan 2017
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Document Summary
The simplest way to expedite a reaction is to add heat; however, cells are limited to ~37 degrees, as excessive heat denatures proteins. Evolution of multifunctional enzymes reactions in cells usually occur as chain reactions, not as single reactions; to increase chain reaction efficiency scaffold protein. Scaffold protein: enzymes are grouped together and stabilized by scaffold protein; scaffold protein only have protein-protein interaction domains, and so can recruit all components required for a reaction to take place; also localizes reaction. Example: map-kinase pathway: an enzyme is activated that phosphorylates a kinase, which phosphorylates another kinase and so on; map-kinase-kinase-kinase phosphorylates map-kinase- kinase activates map-kinase. Proteins can be motors: actin and myosin motor in which myosin slides filaments, producing work; protein motor causes bacteria flagellum to rotate. A motor is something that displaces an object relative to another object: dna and rna polymerases or ribosomes are motors because they produce force and displacement.
