[amand79]

Hi, I don't understand the part in bold about the Michaelis-Menton kinetic model of catalysis, could someone please try and explain it? 

Michaelis-Menton Mechanism
E = enzyme, S = substrate, P = product
Step 1) E + S -> ES [fast, reversible]
Step 2) ES -> E + P [slow, rate-determining] • The substrate binds to the enzyme at the active site to form an enzyme-substrate complex (ES). ES then reacts to form the product in the slow rate determining step. •WhenEa =0 and steric factor A=1 reactions are diffusion controlled - this is as fast as a reaction can go. For 2 molecules of the same size diffn control gives rates which approach the encounter frequency of 7 x 109 s-1 M-1.
• Many enzyme systems approach this rate.
eg. acetylcholinesterase k =1.6 x 109 s-1 M-1

Thank you

[Babcock_Hall]

Welcome to the forum.  One, in general you must give us your thoughts before we can help you.  That is a Forum Rule (see red link above).  Two, you can use your textbook and search this term yourself and get a good start.  Three, your question is broad, making it difficult to answer.  It might refer either to the Michaelis complex or to the Michaelis-Menten equation and its derivation.  My suggestion is that you reframe your question in a way that makes it more focused and provide what you think the answer is and why.