LIFE 102 Lecture Notes - Electron Transport Chain, Allosteric Regulation, Cellular Respiration
Document Summary
Concept 8. 5: regulation of enzyme activity helps control metabolism. A cell regulates metabolic pathways at two levels. Switching on or off the genes that encode specific enzymes. May either inhibit or stimulate an enzyme"s activity. Occurs when a regulatory molecule binds to a protein at one site and affects the protein"s function at another site. Most allosterically regulated enzymes are made from polypeptide subunits. The binding of an activator stabilizes the active form of the enzyme. The binding of an inhibitor stabilizes the inactive form of the enzyme. Cooperativity is a form of allosteric regulation that can amplify enzyme activity. In cooperativity, binding by a substrate to one active site stabilizes favorable conformational changes at all other subunits. Allosteric regulators are attractive drug candidates for enzyme regulation. Inhibition of proteolytic enzymes called caspases may help management of inappropriate inflammatory responses. End product of a metabolic pathway shuts down the pathway.
