Term
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Definition
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Term
| the type of catalysts enzymes are |
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Definition
| powerful and highly specific |
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Term
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Definition
| reactant an enzyme interacts with |
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Term
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Definition
| the hydrolysis of a peptide bond |
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Term
| what causes an enzyme to be specific? |
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Definition
| the precise interaction of the substrate with the enzyme |
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Term
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Definition
| because of its intricate, 3D structure |
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Term
| 6 major classes of enzymes |
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Definition
1: oxidoreductases
2: transferases
3: hydrolyases
4: lyases
5: isomerases
6: ligases |
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Term
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Definition
| transfer electrons between molecules to catalyze redox rxns |
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Term
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Definition
| transfer functional groups between molecules |
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Term
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Definition
| cleaves molecules by the addition of water |
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Term
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Definition
| adds atoms or functional groups to a double bond or removes them to form double bonds |
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Term
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Definition
| they move functional groups within a molecule |
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Term
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Definition
| they join 2 molecules in a rxn powered by ATP hydrolysis |
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Term
| many enzymes require this for activity |
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Definition
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Term
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Definition
| small molecules that help activate an enzyme |
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Term
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Definition
| enzyme without its cofactor |
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Term
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Definition
| the complete, catalytically active, enzyme; has the cofactor |
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Term
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Definition
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Term
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Definition
| small organic molecules derived from vitamins; type of cofactor |
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Term
| prosthetic (helper) groups |
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Definition
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Term
| loosely associated coenzymes are more like... |
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Definition
cosubstrates
they bind to and are released from enzymes |
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Term
| difference between coenzymes and normal substrates |
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Definition
| coenzymes are derived from vitamins and used by a variety of enzymes |
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Term
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Definition
| measures the amount of useful energy, the energy capable of doing work |
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Term
| thermodynamic properties that need to be considered to understand how enzymes operate |
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Definition
1: the free energy difference (ΔG) between the products and the reactants
2: the free energy required to initiate the conversion of reactants into products (activation energy) |
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Term
| thermodynamic property affected by enzymes |
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Definition
| the free energy required to initiate the rxn (activation energy) |
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Term
| ΔG of a rxn determines... |
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Definition
| whether or not the rxn will take place spontaneously |
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Term
| a rxn can occur spontaneously only if... |
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Definition
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Term
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Definition
-rxn that releases energy
-occurs spontaneously
-ΔG negative |
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Term
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Definition
-requires energy input
-not spontaneous
-ΔG positive |
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Term
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Definition
| rxn can't be spontaneous and energy input is required |
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Term
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Definition
| rxn is spontaneous and energy is released |
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Term
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Definition
| the system is at e'librium and there's no net change in energy |
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Term
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Definition
ΔG rxn = ΔG products - ΔG reactants
this is independent of path |
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Term
| some info ΔG does not provide |
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Definition
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Term
| the rate of a rxn depends on... |
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Definition
| the free energy of activation (ΔGt) |
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Term
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Definition
| free energy of activation |
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Term
| the standard free-energy change of a rxn is related to... |
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Definition
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Term
| how to calculate ΔG of a rxn |
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Definition
ΔG = ΔG° + RTln([each product]/[each reactant])
ΔG = free energy change of a rxn
ΔG° = standard free energy change
R = gas constant
T = absolute temperature |
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Term
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Definition
standard free energy change
expressed in kJ/mol |
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Term
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Definition
| gas constant (standard 8.315 X 10-3kJ mol-1 K-1) |
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Term
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Definition
| absolute temperature (standard 298 K) |
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Term
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Definition
standard free energy change at pH 7
expressed in kJ/mol |
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Term
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Definition
0 = ΔG°' + RTln([each product]/[each reactant])
so
ΔG°' = -RTln([each product]/[each reactant])
ΔG = free energy change of a rxn
ΔG°' = standard free energy change at pH 7
R = gas constant
T = absolute temperature |
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Term
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Definition
| e'librium constant under standard conditions |
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Term
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Definition
| K'eq = ([each product]/[each reactant]) |
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Term
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Definition
| ΔG°' = -RTln([each product]/[each reactant])
ΔG°' = -RTln(K'eq) |
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Term
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Definition
| K'eq = [each product]/[each reactant]
K'eq = e-ΔG°'/RT
K'eq = e-ΔG°'/2.47 |
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Term
| the size of ΔG relative to ΔG°' depends on... |
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Definition
| the concentrations of the reactants and products |
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Term
| what enzymes do to e'librium |
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Definition
| accelerate the attainment of e'librium |
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Term
| the e'librium position is a function of... |
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Definition
| only the free energy difference between rxns and products |
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Term
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Definition
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Term
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Definition
| free energy of activation / activation energy |
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Term
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Definition
| difference between free energy of substrate and free energy of transition state |
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Term
| how enzymes lower activation energy |
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Definition
| by facilitating the formation of the transition state |
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Term
| the first step in enzymatic catalysis |
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Definition
| the formation of an enzyme-substrate complex |
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Term
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Definition
| the region of an enzyme that binds to the substrate and cofactor |
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Term
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Definition
| the amino acid residues within active sites that directly participate in making and breaking bonds |
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Term
| the binding of enzyme to substrate is mediated by... |
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Definition
| weak forces, such as H bonding, van der Waals, and electrostatic forces |
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Term
| an enzyme's specificity of binding depends on... |
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Definition
| the percisely defined arrangement of atoms in an active site |
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Term
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Definition
| enzyme adjusting to fit with the substrate |
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Term
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Definition
| certain conformations of an enzyme that a substrate may bind to |
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Term
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Definition
| the free energy released when an enzyme binds to the substrate |
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Term
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Definition
| compound that resembles the transition state of a rxn, but isn't capable of being acted on by the enzyme |
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Term
| what transition-state analogs do to enzymes |
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Definition
| inhibit them by resembling the transition state, but the enzyme can't act on it |
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Term
| An enzyme will specifically bind its substrate primarily because of... |
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Definition
| A large number of weak interactions at the active site |
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