Enzyme Kinetics

Enzyme Kinetics

when an enzyme is incubated with substrates the reaction rate decreases over time either because of substrate depletion or product inhibition
initial rate = Vo
if the initial rate is measured the reaction velocity is linearly related to the amount of enzyme
Michaelis-Menton
1. proposes = rate of reaction is determined by the rate of formation of enzyme-substrate complex at low substrate concentrations but eventually something other than the ES complex becomes limiting
  1. constant Km = concentration of substrate at which the rate is half maximal
    1. 1/V against 1/S gives a straight line from which Km can be determined as can Vmax.
    2. provided that the dissociation rate of the enzyme-substrate complex is much greater than the rate of formation of products Km represents the dissociation constant.
    3. most enzymes in the cell operate at substrate conc below Km
      1. typical values = 10 to the minus 4 and 10 to the minus 6 M
2. high substrate conc. = all enzyme is present as ES and enzyme is saturated with substrate. Rate of reaction = Vmax.
  1. an enzyme following this with velocity against substrate plotted will have a hyperbolic shape

Resource summary

	Created by kathrynmoar over 10 years ago