The Biology Project > Biomath > Rational Functions > Applications > Hill Equation

## Hill Equation

Problem 5- Determine if an enzyme exhibits cooperativity.

 When n = 1, the Hill equation reduces to the Michaelis-Menten equation, Recall that we can make a double reciprocal plot of the Michaelis-Menten equation using the Lineweaver-Burk equation, Notic that 1/V is a linear function of 1/[S] in the Lineweaver-Burk equation. We can also take the reciprocal of both sides of the Hill equation as, Notice that 1/V is now a power function of 1/[S]. When there is no cooperativity, n = 1, the graph of 1/V versus 1/[S] will be a straight line. On the other hand, when there is positive cooperativity, i.e. n > 1, then the graph of 1/V versus 1/[S] will be concave up; and when there is positive cooperativity, i.e. n < 1 then the graph of 1/V versus 1/[S] will be concave down. Using the above information, does the enzyme pictured in the cartoon plot below exhibit positive, negative, or no cooperativity?
 A. Positive cooperativity B. Negative cooperativity C. No cooperativity

End of problems.

The Biology Project > Biomath > Rational Functions > Applications > Hill Equation

The Biology Project
Department of Biochemistry and Molecular Biophysics

The University of Arizona

March 2007
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