Regulation of Enzyme Activity

Regulation of Enzyme Activity - bind irreversibly For...

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Regulation of Enzyme Activity Cells have built-in control mechanisms to regulate enzyme concentration and activity. Regulation of Protein Synthesis (Genetic Regulation) Enzymes are proteins. You can regulate them by making more or less of them as needed. The topic of regulating protein synthesis is deferred to a later chapter. Regulation of Enzymes Already Produced Competitive Inhibition In competitive inhibition, a similar-shaped molecule competes with the substrate for active sites . Noncompetitive Inhibition Another form of inhibition involves an inhibitor that binds to an allosteric site of an enzyme. An allosteric site is a different location than the active site. The binding of an inhibitor to the allosteric site alters the shape of the enzyme, resulting in a distorted active site that does not function properly. The binding of an inhibitor to an allosteric site is usually temporary. Poisons are inhibitors that
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Unformatted text preview: bind irreversibly. For example, penicillin inhibits an enzyme needed by bacteria to build the cell wall. Feedback Inhibition Negative feedback inhibition is like a thermostat. When it is cold, the thermostat turns on a heater which produces heat. Heat causes the thermostat to turn off the heater. Heat has a negative effect on the thermostat; it feeds back to an earlier stage in the control sequence as diagrammed below. Many enzymatic pathways are regulated by feedback inhibition. As an enzyme's product accumulates, it turns off the enzyme just as heat causes a thermostat to turn off the production of heat. The end product of the pathway binds to an allosteric site on the first enzyme in the pathway and shuts down the entire sequence. Feedback inhibition occurs in most cells....
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Regulation of Enzyme Activity - bind irreversibly For...

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