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# Enzyme Kinetics & Steady State

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For a MM reaction
k1=5x10^7
k-1=2X10^4
k2=4x10^2

i calculated Km and Ks to be equal at about 4 x10^-4M

Does substrate binding achieve equilibrium or the steady state?

Could you clarify when you have ph=pkA how you get whether it is -1/2 or +1/2 or in the other case +1/3 or -1/3. How do you tell whether it is + or -

#### Solution Preview

ENZYME KINETICS -- EQUILIBRIUM VS. STEADY STATE CONDITIONS

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for a Michaelis-Menten reaction:

k1=5x10^7
k-1=2x10^4
k2=4x10^2

Km = (k-1 + k2)/k1 = 4x10^-4

Km = Ks + (k2/k1), therefore:

Ks = Km - (k2/k1) = 4x10^-4

Therefore, your calculations are correct. Km and Ks are about equal at 4x10^-4 M.

Question: Does substrate binding achieve equilibrium or the steady state?

Response: The assumption made in the equilibrium derivation is that k-1 >> k2. In other words, the ES complex can be assumed to dissociate back to E + S almost exclusively, and not to E + P. That means that E, S and ES are assumed to be in equilibrium. That's why we base our calculations on Ks, ...

#### Solution Summary

484-word solution includes calculations for a Michaelis-Menten reaction and a conceptual explanation of the pH=pkA equation.

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## Physical Chemistry Collision Theory

I have a list of terms that needs to be defined in a Physical Chemistry course. With each definition I need an example for each term, as a description to it or so

term Chapter
collision theory
transition state theory
rate constant
Arrhenius equation
integrated rate law
rate law
activation energy
pseudo first order
preexponential factor (a)
half life
zeroth order reaction
first order reaction
second order reaction
third order reaction
method of initial rates
isolation method
reaction profile
collision frequency
reaction coordinate
flash photolysis
stopped flow experiment
temperature jump experiment
elementary reactions
consecutive reactions
unimolecular reactions
molecularity
rate-determining step
diffusion-controlled limit
Homogeneous catalyst
catalyst
heterogeneous catalyst
Michealis- Menten kinetics
KM Michealis constant
Maximum Turnover number
Maximum Velocity
Line-Weaver-Burke Plot
Woolf Plot