Biology Lecture 20

Biology Lecture 20 - Noncompetitive inhibitors bind to...

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Biology Lecture 20 Enzymes change the rate at which a reaction would occur Activation energy is often supplied in the form of heat Delta G is unchanged Enzymes act on substrates Form an enzyme-substrate complex The active site is where the substrates bind Induced fits enhances the ability of an enzyme to catalyze the reaction by making the substrate fit snugly in its active site The active site can lower EA barrier by Orienting substrates correctly Straining substrate ponds Provides a favorable microenvironment Covalently bonding to the substrate Changes in pH and temperature influence the shape of the enzyme, therefore influencing its function. Cofactors (non protein helpers) can also affect the enzyme’s activity. Organic cofactors are usually called coenzymes Competitive inhibitors bind to the active site If you add more substrate, the substrate will compete with the inhibitor for the active site
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Unformatted text preview: Noncompetitive inhibitors bind to another area of the enzyme. By binding there, the shape of the enzyme changes Not all inhibitors are bad because some help regulate the cells functions Allosteric (change in shape) regulation may inhibit or stimulate an enzyme’s activity Regulatory molecule can be a natural one (can be reversible) Allosterically regulated enzymes are made from 2 or more polypeptide subunits Each enzyme has active and inactive forms Activator stabilizes the active form of an enzyme Inhibitor stabilizes the inactive form of an enzyme Cooperativity is a form of Allosteric regulation that can amplify (increase) enzyme activity Binding by a substrate to one active site stabilizes and causes the other active sites to pump up their activity Office hours Monday 12pm to 2pm...
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