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21 Cards in this Set
- Front
- Back
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The 4 common catalytic strategies
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Covalent Catalysis
Acid-Base Catalysis Metal Ion Catalysis Catalysis by Approximation |
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The 3 ways that metal ions interact in catalysis
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Serves as an electrophile
Generates a nucleophile Binds to a substrate |
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Chymotrypsin cleaves proteins on the ______ side of _______ or ______
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carboxyl side
of aromatic ring or large hydrophobic amino |
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Peptide bonds are stable due to
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resonance and partial double-bond character
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Peptide bonds require a strong _______ to be cleaved
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nucleophile
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The catalytic triad consists of
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Asp - His - Ser
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The most important part of the catalytic triad is _____ because it's a potent _______ that forms _______
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Ser
nucleophile alkoxide ion |
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The active site of chymotrypsin is a ________ with a _______
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hydrophobic pocket
aromatic ring |
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Determines the specificity of chymotrypsin
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side chains in the hydrophobic pocket
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explain strategy: Covalent Catalysis
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active site contains a reactive group/nuceophile which becomes covalently modified
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explain strategy: Acid Base Catalysis
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molecule other than H2O is the proton donor or acceptor
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explain strategy: Metal Ion Catalysis (hint: 3 methods)
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1. serves as an electrophile, stabilizing a negative charge
2. generates a nucelophile by increasing acidity of a nearby molecule 3. binds to substrate, increasing number of interactions with the enzyme |
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explain strategy: Catalysis by Approximation
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bringing 2 substrates together along a single binding surface of an enzyme
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Human Carbonic Anhydrase II hydrates CO2 at this rate
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a million times/sec
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Human Carbonic Anhydrase II is found in this
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red blood cells
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Mutations of Carbonic Anhydrase can cause
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osteopetrosis
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The 1st discovered zinc-containing enzyme was
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Carbonic Anhydrase
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the binding of zinc does this to water
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lowers pKa from 15.7 to 7.0
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The 4 steps of carbonic anhydrase
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1. proton is released from H2O
2. CO2 attacks 3. HO- attack converts CO2 to HCO3- 4. HCO3- is released and a new H2O binds |
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These enzymes transfer phosphates
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kinases
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these act as a lid to keep H2O out
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p-loops
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