For a MM reaction
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 -© BrainMass Inc. brainmass.com September 20, 2018, 12:46 am ad1c9bdddf - https://brainmass.com/biology/enzyme-catalysts-and-reactions/enzyme-kinetics-steady-state-69875
ENZYME KINETICS -- EQUILIBRIUM VS. STEADY STATE CONDITIONS
for a Michaelis-Menten reaction:
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, ...
484-word solution includes calculations for a Michaelis-Menten reaction and a conceptual explanation of the pH=pkA equation.