Answer Happy

a. From the graph below determine
the Km of PGI for
G-6P, and the Vmax for the formation
of F-6P
Note: make sure to accompany all answers with their units,
where appropriate.
b. Knowing that PGI has a molecular weight of 50 kDa,
what is the turnover number for the reaction as written above? Show
your work!
c. If k-1 is 10,000 1/min
and k-2 is negligible, what is
the KD for the ESP complex in the
direction of the free enzyme and G-6P. Show your work!
The following reaction is catalyzed by PGI (phosphoglucoisomerase enzyme), the second enzyme-catalyzed reaction in glycolysis, where k₁ is the rate constant for the formation of the enzyme-substrate-product complex, ESP, from G-6P, k.₁ is the rate constant for the dissociation of the ESP to free enzyme and G-6P, k₂ is the rate constant for the dissociation of the ESP to free enzyme and F-6P, and k-2, is the rate constant for the formation of the ESP from free enzyme and F-6P. OH H -OH HO- k₂ HO H H- [ESP] H -OH H- -OH K.₁ H- -OH O Po ő- Glucose-6P (G-6P) Fructose-6P (F-6P) The kinetics for the forward reaction (i.e., as written from left to right) were measured under the conditions where at time t = 0, [F-6P] = 0. The [G-6P] was varied, and the following data were obtained. (Chapter 6) -H OH ~1/= K-2

[G-6P] mM 0.1 0.3 0.5 1.0 5.0 10.0 1/V, (mg-min/μmol) 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 -1 0 1 Voumol F-6P formed/(min-mg enzyme) 5 13 20 33 71 83 2 3 4 5 6 7 1/[G-6P] (1/mM) 8 9 10 11