Extra Problems Exam II KEY

First calculate the slope yx using the inverse rates

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: way to calculate Km is to use the michaelis- menton (M- M) equation, Vo = Vmax [S] / (Km + [S]), substituting 140mM/min for Vmax along with any non- Vmax [S], Vo pair (in their given form). You cannot use rate, substrate pairs where the rate is Vmax because the math does not yield useful information if the rate does not change as a function of [S]. 95 = 140(20)/ (Km + 20) 95Km + 1900 = 2800 95Km = 900 Km = 9.5 μM Method 2: If you calculated the slope as above, you could simply use the slope to determine Km. Slope = Km/ Vmax, therefore, Km = slope x Vmax = 0.073*141 = 10 μM 13 b. The Vmax will not change in the presence of a competitive inhibitor. 13 c. 65% inhibition indicates that the maximal rate in the presence of inhibitor is 35% of the maximal rate in the absence of inhibitor. Vmax app/ Vmax = 0.35 and Vmax app = Vmax / α" Therefore, 0.35 = 1/α" α" = 1 + [I]/K"I so, 0.35 = 1/ (1+ [I]/4 x 10- 4) Solving for [I], you get 7.4 x 10- 5 M 14. The turnover rate for an enzyme that follows Michaelis- Menton kinetics is 4 min- 1. In an experiment using 120 nM enzyme, the following data were obtained. __[S] (mM) 1/[S] __Vo (μM/min) 1/Vo (min/mM) 1.5 0.67 0.16 6250 2.5 0.40 0.22 4545 3.5 0.29 0.26 3846 4.5 0.22 0.29...
View Full Document

This homework help was uploaded on 03/02/2014 for the course BIOCHEMIST 395 taught by Professor Potenza during the Spring '14 term at NMSU.

Ask a homework question - tutors are online