biochemists consider the citric acid cycle to be the central reaction sequence in metabolism. One of the key steps is an oxidation catalyzed by the enzyme isocitrate dehydrogenase and the oxidizing agent NAD+. Under certain conditions, the reaction in yeast obeys 11th-order kinetics:
rate= k[enzyme][isocitrate]^4[AMP]^2[NAD+]m[Mg2+]^2
What is the order with respect to NAD+?
answer is 2
11= 1 + 4 + 2 + m + 2
solve for m.
the overall order is found by adding all of the other orders together. the overall order is given so you need to subtract all of the known orders to get m. k[enzyme] has an order of 1.
To determine the order with respect to NAD+ in the given reaction, we need to analyze the reaction rate equation provided:
rate = k[enzyme][isocitrate]^4[AMP]^2[NAD+]^m[Mg2+]^2
Here, the exponent 'm' represents the order with respect to NAD+. Since we are specifically interested in finding the order with respect to NAD+, we can consider the concentration of all other reactants as constant.
To determine the order with respect to NAD+, we can use the method of initial rates.
1. Conduct several separate experiments by keeping the concentrations of all the reactants (except NAD+) constant, while varying the concentration of NAD+.
2. Measure the initial reaction rate for each experiment by noting the rate of change of the reactants at the beginning of the reaction.
3. Compare the initial reaction rates for each experiment.
If we observe that doubling the concentration of NAD+ results in a doubling of the initial reaction rate, then we conclude that the reaction is first order with respect to NAD+. If doubling the concentration results in a fourfold increase in the initial reaction rate, then the reaction is second order with respect to NAD+.
By comparing the initial reaction rates at different NAD+ concentrations, we can determine the exponent 'm' and identify the order with respect to NAD+ in the equation.
11=4+2+m+2
Solve for m