# Shared Flashcard Set

## Details

Biochem Ch. 7.1-7.2
Biochem Ch. 7.1-7.2
43
Biochemistry
01/06/2018

Term
 kinetics
Definition
 study of chemical rxns
Term
 enzyme kinetics
Definition
 study of the rates of enzyme-catalyzed rxns
Term
 velocity of a rxn (V)
Definition
 quantity of reactant that disappears in a specified unit of time
Term
 how to calculate velocity of a rxn (V)
Definition
 V = -d[A]/dt = d[P]/dtV = velocity of rxnd = decrease in substrate concxentration or increase in product concentrationt = timeA = reactant AP = product P
Term
 velocity of rxn (V) vs. rate constant (k)
Definition
 V = k[each reactant]V = velocity of rxnk = rate constant
Term
 first-order rxn
Definition
 rxn in which the velocity is directly proportional to the reactant concentration have unit s-1
Term
 second-order rxn
Definition
 rxn that includes 2 reactants have units M-1 s-1 (per mole per second)
Term
 pseudo-first-order rxns
Definition
 second-order rxns that appear to be first-order rxns
Term
 zero-order rxn
Definition
 rxn in which rate is independent of rxn concentration
Term
 rate equation of a first-order rxn
Definition
 V = k[A]
Term
 rate equation of a second-order rxn
Definition
 V = k[A]2 or V = k[A][B]
Term
 this is a necessary intermediate in catalysis
Definition
 a specific ES complex
Term
 Michaelis-Menton equation
Definition
 V0 = Vmax X ([S]/([S] + KM)) V0 = initial velocity Vmak = maximum velocity S = substrate KM = Michaelis constant
Term
 Michaelis constant
Definition
 KM = (k-1 + k2)/k1
Term
 how to calculate Vmax
Definition
 Vmax = k2[E]T
Term
 when Vmax can be obtained
Definition
 when total enzyme (ET) is attained
Term
 when the enzyme is said to be saturated
Definition
 when all the available enzyme is bound to the substrate and displaying zero-order kinetics
Term
 KM is equal to...
Definition
 the substrate concentration at which the rxn velocity is half its maximal value
Term
 Lineweaver-Burk equation
Definition
 1/V0 = (KM/Vmax) X (1/S) + (1/Vmax)
Term
 the KM value of an enzyme varies based on...
Definition
 substrate and environmental conditions
Term
 enzymes when substrate concentration is below KM
Definition
 enzymes have little activity and are sensitive to changes in substrate concentration
Term
 enzymes when substrate concentration is above KM
Definition
 enzymes have much activity and are insensitive to changes in substrate concentration
Term
 enzymes when substrate concentration is approximately KM
Definition
 enzymes have much activity and are sensitive to changes in substrate concentration
Term
 maximal velocity (Vmax) reveals...
Definition
 an enzyme's turnover number
Term
 an enzyme's turnover number
Definition
 the number of substrate molecules than an enzyme can convert into product per unit time when the enzyme is fully saturated with substrate
Term
 this limits theb rate of formation of the ES complex
Definition
 diffusion; can't be faster than the diffusion controlled enzyme-substrate encounter
Term
 kinetic perfection
Definition
 when catalytic velocity is restricted only by the rate at which enzymes encounter substrate in the solution
Term
 when enzymes have kinetic perfection
Definition
 when they have their Kcat/KM ratios at their upper limits
Term
 the 2 classes of multiple substrate rxns
Definition
 1: sequential rxns2: double-displacement rxns
Term
 sequential rxns
Definition
 all substrates must bind to the enzyme before any product is released
Term
 bisubstrate rxn
Definition
 rxn where a ternary complex forms
Term
 ternary complex
Definition
 consists of enzyme and both substrates
Term
 the types of sequential mechanisms for sequential rxns
Definition
 -ordered-random
Term
 ordered mechanism for sequential rxns
Definition
 substrates bind to the enzyme in a defined sequence
Term
 double-displacement (ping-pong) rxns
Definition
 one or more products are released before all substrates bind the enzyme
Term
 the defining feature of double-displacement rxns
Definition
 the existence of a substituted enzyme intermediate
Term
 substituted enzyme intermediate
Definition
 in a double-displacement rxn, this is when the enzyme is temporarily modified
Term
 representation of sequential rxn
Definition
 [image]
Term
 representation of double-displacement rxn
Definition
 [image]
Term
 which parameter of an enzyme-catalyzed rxn depends on enzyme concentration?
Definition
 Vmax (maximum velocity)
Term
 KM is the equivalent of...
Definition
 Substrate concentration when 1/2 Vmax is reached
Term
 what parameter of an enzyme-catalyzed rxn is a measure for the affinity of its substrate?
Definition
 KM
Term
 When a substrate concentration is MUCH greater than KM, the rate of catalysis is almost equal to...
Definition
 Vmax
Supporting users have an ad free experience!