Enzymes AP Biology General Information l Globular proteins
Enzymes AP Biology
General Information l Globular proteins Unique 3 dimensional shape l Active site: pocket or groove where substrate binds l
General Information l Catalysts l l l Speed up chemical reactions Lower activation energy Not used up in chemical reaction
General Information l Substrate l Enzyme specific substrate pairs Catalase – hydrogen peroxide l Sucrase – sucrose l
Action – Induced Fit Model l Substrate binds to enzyme at active site l Interaction between substrate and active site
Action – Induced Fit Model l Bonds in substrate stressed l Bonds break l Products released
Action – Induced Fit Model l Substrate binds to enzyme at active site l Interaction between substrate and active site l Bonds form between reactants
Temperature & Rate l Increasing temperature increases rate l l Increase temperature increases speed of molecules Increase speed of molecules increases number of collisions
Temperature & Rate l Optimal l temperature Temperature that produces max. rate.
Temperature & Rate l Temperature above optimal Enzyme denatured (changes shape) l Reaction drops then stops l
p. H & Rate l Optimal l p. H with at max. rate
p. H & Rate l Above optimal – rate decreases l Lower [H+] interferes with enzyme shape
p. H & Rate l Below optimal – rate decreases l Higher [H+] interferes with enzyme shape
p. H & Rate l Extreme changes – rate zero l Enzyme denatures
Control of Chemical Reactions l Inhibitors – Competitive l Inhibitor competes with substrate for active site
Control of Chemical Reactions l Inhibitors – Noncompetitive l Inhibitor binds to site other than active site
Control of Chemical Reactions l Allosteric Enzymes Two conformations – active & inactive l Activator stabilizes active form l Inhibitor stabilizes inactive form l
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