Question

7. What assumptions do we make in deriving Michaelis-Menten equation and what combination of elementary constants and/or concentrations make these assumptions invalid?

Answer 1

Three assu ee assumptions are implicit in Michaels- Menton equation - Ky [ 1E).- L'Es7] [s] = K-, [ES] + K,[ES] The Steady - State approxima Hon The free tigand approximation K, E]. [S] -K,[ES][S] = k1,[ES]+ , ES] The Rapid ewlibrium approximation Sterci) The Substrate molecule binds to K, E). [s] - [K, [S] + ku + ka) [ES] Enzyme active Site On Enzyme Sun face to form rrenzyme Substrate ACTIVATED COMPLEX [es] = k LE] [s] Ets -ki ES k(s]+ k., tka Sterii) The enzyme Substrate complex Put in may again yield the substrate 91 ke ke [E].[5] eeule & Enzyme Site is again free. ES K Ets k, [s] + K, tka Sterii) The Enzyme substrate Complex "At max de max rate, may also decompose into products (E). = [ES] ES - ke PTE I put value of [ES] in &qu ® Now we will derive the Rate law Expressioni- may rate will be E+ S E S (fast) Step 162 ore reversible to each rmax = K2[E] ES ke E+P (slow) other is They are Slow) fost reactions to put value of rmax in & @ The Rate of product Step 3 is slow formation :- it is RDS Ir kirmoxis] 8=ko [ES] 0 Rp [s] +(K-1 tk.) Apply ssa on [ES] Dinde Egh by ko Rate of formation of ES = Rate of Deformation of ES = Kirmax [s] KLE): () - K., [ES] + K, ÉS] - [E]. - [E]: + [ES] - K[s] + [kitka] Conchore Conchob conch of ES at kritial Eat time at time t r = rmax [s] time [s] + (k. 1 tko Totallites = Un occupied + Occupied [E]. - Ele+ [ES] km = kitkat Michaelis to -[]. = 15), At mox Sláte zmer) + (E).= [ES] 6 rmar [s] Rate we get [E1 = [E] - LESIE - [s]+ komp put value of [E] in 8gh of what site I - - Te T Menton constant ie initially it is Michaelis - Menton Equation