The Behavior of Proteins: Enzymes, Mechanisms and Control Chapter 7

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What are allosteric enzymes?  Allosteric:  Allosteric: Greek allo + steric - other + shape  Allosteric enzyme:  Allosteric enzyme: an oligomer whose biological activity is affected by other substances binding to it these substances change the enzyme’s activity by altering the conformations of its 4°structure

How are allosteric enzymes controlled?  Allosteric effector:  Allosteric effector: a substance that modifies the behavior of an allosteric enzyme allosteric inhibitor allosteric activator

How are allosteric enzymes controlled?  End product of the sequence of reactions inhibits first reaction in the series

Allosteric Enzymes  The key to allosteric behavior is the existence of multiple forms for the 4°structure of the enzyme allosteric effector: allosteric effector: a substance that modifies the 4° structure of an allosteric enzyme homotropic effects: homotropic effects: allosteric interactions that occur when several identical molecules are bound to the protein heterotropic effects: heterotropic effects: allosteric interactions that occur when different substances are bound to the protein

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