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In: Chemistry

For the simple enzyme model E + A<---> EA<---> E + P (with rate constants k1,...

For the simple enzyme model E + A<---> EA<---> E + P (with rate constants k1, k2, k3) Derive the expressions for the fraction of the total enzyme present as the free enzyme and for the fraction of the total enzyme present as the EA complex (simply the expressions to ensure they only contain A and Km as terms). Plot (E)/Et and (EA)/Et as a function of (A)/Km. Vary (A)/Km = 0.1 to 10 over about 10 concentrations. Say in a few words what this plot tells you

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For the simple enzyme model E + A<---> EA<---> E + P (with rate constants k1, k2, k3) Derive the expressions for the fraction of the total enzyme present as the free enzyme and for the fraction of the total enzyme present as the EA complex (simply the expressions to ensure they only contain A and Km as terms). Plot (E)/Et and (EA)/Et as a function of (A)/Km. Vary (A)/Km = 0.1 to 10 over about 10 concentrations. Say in a few words what this plot tells you

E + A<---> EA<---> E + P

In such reactions rate of product formation is given by,

V= d[P]/dt

= Vmax * [A]/Km + [A]

The reaction rate increases with increasing substrate concentration [A], by approaching its maximum rate Vmax, attained when all enzyme is bound to substrate.

The Michaelis constant Km is the substrate concentration at which the reaction rate is at half-maximum, and is an inverse measure of the substrate's affinity for the enzyme—as a small Km indicates high affinity, meaning that the rate will approach Vmax more quickly. The value of Km is dependent on both the enzyme and the substrate and also other factors such as pH and temperature.


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