Enzymology
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What do lipases do?
They catalyse the hydrolysis of triglycerides

Are inorganic catalysts homogeneous or heterogeneous?
heterogeneous

How do you calculate 1st order kinetics?
ln(A_{t}/A_{0})=k_{1t}

How can you rewrite 1st order kinetics equotation if A0 is constant?
lnA_{t} =k_{1t} + C

How do you calculate the halflife in 1st order reactions?
t_{1/2} =ln2/k_{1}

What is a pseudo first order reaction?
e.g. a 2nd order reaction with water, so that (B) can be seen as constant and kinetics are more that of a first order reaction

How do you calculate the rate constant in pseudo 1st order reactions?
k_{2}(CH_{3}I)(H_{2}O)= k_{1}'(CH_{3}I) where k_{1}' = k_{2}(H_{2}O)

What is true for reversible reactions at equilibrium?
Bt is constant, so k_{1}A_{e }= k_{1}B_{e }= K_{1}x_{e}

what is the steady state approach?
Assume (A.B) is constant

How do you calculate the rate constant for preequilibria?
k_{2}(A.b)= (k_{1}k_{2}AB)/(k_{1}k_{2})

Which possibilities are there for preequilibria?
 k_{2}>>k_{1} and v=k_{1}AB
 k_{1}>>k_{2 } and v= k_{2}KAB

What is the Arrhenius equotation?
k_{obs}= A exp( E_{a}/RT)

How can you determine E_{a}?
 Measure at 2 different temperatures
 k_{1}/k_{2} = exp (E_{a}/R (1/T_{1}1/T_{2}))

How do you calculate the reaction rate if (A_{0}) = (B_{0})?
1/A_{t}  1/A_{0} = k_{2 }t

What does x stand for in rate constant calculations?
The concentration of product

What is K?
The equilibrium constant k_{1}/k_{1
}You can also calculate it by x_{e}/ (A_{0}x_{e})

What is K** and how do you calculate it?
It is the rate constant for formation of the transition state and is calculated by X**/(AB)

What is k**?
The reaction rate between transition state and product

What is k_{B}?
The Boltzmann constant

What is h?
Planck's constant

What is true concerning G in equilibria?
G^{0}= RTlnK

Which are the Eyring equotations?
 k= (k_{B}T/h) exp (G**/RT)
 k= (k_{B}T/h) exp (H**/RT) exp (S**/R)

What is the procedure to obtain activation parameters?
 1. determine k at different T
 2. plot ln(k/T) against 1/T
 3. the slope is H**/R
 4. use Eyring to obtain S**
 5. obtain G** from G=HTS

What does the value for S** tell you?
 if S = 0 J/molK, then the reaction is monomolecular
 if S < 0 J/molK, then the reaction is bimolecular

What is more solvated: ions in ground state or in transition state?
In general, ions in ground state are more solvated

What effect does solvation have on E_{A}?
It makes it bigger

What is the Hammond Postulate?
The transition state closely resembles the species with the highest energy content

What is the primary isotope effect?
Differences in bond strength depend on size of the molecule and affect reactivity

How can you calculate the maximum primary isotope effect?
The difference in k for the two different isotopes is the primary isotope effect

What does the primary isotope effect tell you?
 if k_{H}/k_{D} = 47, then bond cleavage and symmetrical transition state
 if k_{H}/k_{D} = 14, then bond cleavage, asymmetrical transition state

Which types of proton transfer are there?
 Fast, to N,O,S
 Slow, to C
 Diffusion dependent, from H_{3}O^{+} to N or O

What are criteria for a nucleophilic catalyst?
 The catalyst has to react faster than the nucleophile (good nucleophile)
 The intermediate has to react faster with the nucleophile than the starting material (good leaving group)

How can you calculate the nucleophilic power?
 With the Edwards equotation
 log (k/k_{0}) = alpha P + beta H
 where k_{0 }is the rate constant with standard nucleophile
 P is polarisability
 H is basicity (= pK_{a} + 1.74)

What are limits of the Edwards equotation?
 Does not take solvent into account
 does not take the alpha effect into account

What is the alpha effect?
If a nucleophile has a free electron pair on the atom immediately next to the nucleophile atom, it is much more reactive.

What are properties of hard nucleophiles?
hardly polarisable, strong base

What are properties of hard electrophiles?
Hardly polarisable

What is the Bronsted plot?
 There is a linear correlation between log k and pK_{A }
 in general base catalysis