BIOL 1001Feb26

BIOL 1001Feb26 - QUIZ: why can certain enzymes break down...

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BIOL 1001 Feb.26 Metabolism Metabolism: sum of all the chemical reactions in a cell Exergonic + Endergonic = Metabolism Metabolic pathway: series of reactions linked in a sequence Fig. 6-7 Reactants are substrates Enzymes can take same substrates and make a different product How is metabolism controlled? 1. Enzymes regulate chemical rxn (reaction) 2. Cells couple rxns 3. E carriers (ATP) capture E from exergonic rxns to deliver to endergonic rxns Catalysts 1. Catalysts speed up chemical reactions 2. Enzymes are biological catalysts [ most of the time a protein] a. Usually proteins b. Sometimes other things, like RNA 5 properties of Biological Catalysts 1. Speed up chemical rxns 2. Speed up rxns that would occur anyway 3. Not consumed in the rxns 4. Enzymes are very specific 5. Enzyme activity is regulated ^Top 3 all catalysts^ Bottom 2 Enzymes only Fig 6-9 1. Substrates enter active site 2. Shape change promotes reaction 3. Product released;
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Unformatted text preview: QUIZ: why can certain enzymes break down starch (glucose polymer), but not cellulose (glucose polymer)? a. Enzymes speed up rxns b. Enzymes arent consumed c. Enzymes are very specific d. Enzymes are regulated Enzyme Reaction 1. Regulate synthesis 2. Make them inactive; activate when needed: a. Feedback inhibition b. Allosteric regulation c. Competitive inhibition Enzyme Regulation: Feedback inhibition Slowing down production of pathway Coming back to earlier point Enzyme Regulation: Allosteric Regulation Allosteric- changing the shape Regulation Shape of active site changed When turned off negative allosteric regulation Turn on- positive allosteric regulation Changing shape Can occur naturally in cell Competitive Inhibition: No second site; something comes in and blocks active site Competitive inhibitor occupies active site...
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This note was uploaded on 04/07/2011 for the course BIOL 1001 taught by Professor Minor during the Spring '08 term at LSU.

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BIOL 1001Feb26 - QUIZ: why can certain enzymes break down...

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