In general, Please explan how to get > Condition No inhibitor max Thus, the y-intercept is equal to 1/Vmax and the x-intercept is equal to -1/Km. (a) 5 mM inhibitor (2) 5 mM inhibitor (3) 1 YOL ט K 1 1 10 X+ V [S] V max Vmax (umol/mL-sec) 51.2 Vmax,app 49.9 22.8 Km (MM) 3.2 Km,app 10.6 3.1 mst

Principles of Instrumental Analysis
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Chapter34: Particle Size Determination
Section: Chapter Questions
Problem 34.10QAP
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4. Graphing the results from kinetics experiments with enzyme inhibitors
The following kinetic data were obtained for an enzyme in the absence of inhibitor (1), and in the
presence of two different inhibitors (2) and (3) at 5 mM concentration. Assume [Er] is the same in
each experiment.
[S]
(mM)
1
2
4
8
12
1
2
4
8
12
[S]
(mm)
a. Determine Vmax and Km for the enzyme.
b. Determine the type of inhibition and the Kıfor each inhibitor.
1/[S]
M-1
Plot these data as double-reciprocal Lineweaver-Burk plots and use your graph to answers a.
and b.
1000
500
250
125
83.3
Answer: The data may be analyzed using double-reciprocal variables. For each [S] and corresponding u, we
will calculate 1/[S] and 1/v.
sed to get mo
Helmien
(1)
v (μmol/mL sec
12
20
29
35
40
1/v (1)
v (1)
μmol/mL se mL-sec/umol
C
12
20
29
35
40
Please explain
how to get
K
1/v
20 × 104
10 × 104
-400
8.33x104
5.00x104
3.45x104
2.86x104
2.50x104
Condition
No inhibitor
0
5 mM inhibitor (2)
5 mM inhibitor (3)
Plots of 1/v vs. 1/[S] indicate straight lines given by
(1) 1/v = 63.2(1/[S] ) + 1.95 x 104
(2) 1/v = 211.8(1/[S]) +2.00 x 104
(3) 1/ 137.2(1/[S)) + 4.38 x 104
In general,
v (2)
μmol/mL sec
400
(2)
v (µmol/mL sec
4.3
8
14
1/[S]
1- K
4.3
8
14
21
26
800
26
m x
1 1
+
V [S] V
max
max
Thus, the y-intercept is equal to 1/Vmax and the x-intercept is equal to -1/Km.
(a)
Vmax,app
49.9
22.8
1/v (2)
mL sec/µmol
Vmax (umol/mL sec)
51.2
2.33x105
1.25x105
7.14x104
4.76x104
3.85x104
1200
(3)
v (µmol/mL sec
5.5
9
13
16
18
v (3)
1/v (3)
μmol/mL se mL-sec/μmol
Km (mm)
3.2
Km,app
10.6
3.1
inhibitor 3
inhibitor 2
no inhibitor
с
5.5
9
13
16
18
1.82×105
1.11×105
7.69x104
6.25x104
5.56x104
(b) Inhibitor (2) increases the apparent Km of the enzyme without affecting Vmax. This is characteristic of a
competitive inhibitor. In this case Ki is calculated as follows
Transcribed Image Text:4. Graphing the results from kinetics experiments with enzyme inhibitors The following kinetic data were obtained for an enzyme in the absence of inhibitor (1), and in the presence of two different inhibitors (2) and (3) at 5 mM concentration. Assume [Er] is the same in each experiment. [S] (mM) 1 2 4 8 12 1 2 4 8 12 [S] (mm) a. Determine Vmax and Km for the enzyme. b. Determine the type of inhibition and the Kıfor each inhibitor. 1/[S] M-1 Plot these data as double-reciprocal Lineweaver-Burk plots and use your graph to answers a. and b. 1000 500 250 125 83.3 Answer: The data may be analyzed using double-reciprocal variables. For each [S] and corresponding u, we will calculate 1/[S] and 1/v. sed to get mo Helmien (1) v (μmol/mL sec 12 20 29 35 40 1/v (1) v (1) μmol/mL se mL-sec/umol C 12 20 29 35 40 Please explain how to get K 1/v 20 × 104 10 × 104 -400 8.33x104 5.00x104 3.45x104 2.86x104 2.50x104 Condition No inhibitor 0 5 mM inhibitor (2) 5 mM inhibitor (3) Plots of 1/v vs. 1/[S] indicate straight lines given by (1) 1/v = 63.2(1/[S] ) + 1.95 x 104 (2) 1/v = 211.8(1/[S]) +2.00 x 104 (3) 1/ 137.2(1/[S)) + 4.38 x 104 In general, v (2) μmol/mL sec 400 (2) v (µmol/mL sec 4.3 8 14 1/[S] 1- K 4.3 8 14 21 26 800 26 m x 1 1 + V [S] V max max Thus, the y-intercept is equal to 1/Vmax and the x-intercept is equal to -1/Km. (a) Vmax,app 49.9 22.8 1/v (2) mL sec/µmol Vmax (umol/mL sec) 51.2 2.33x105 1.25x105 7.14x104 4.76x104 3.85x104 1200 (3) v (µmol/mL sec 5.5 9 13 16 18 v (3) 1/v (3) μmol/mL se mL-sec/μmol Km (mm) 3.2 Km,app 10.6 3.1 inhibitor 3 inhibitor 2 no inhibitor с 5.5 9 13 16 18 1.82×105 1.11×105 7.69x104 6.25x104 5.56x104 (b) Inhibitor (2) increases the apparent Km of the enzyme without affecting Vmax. This is characteristic of a competitive inhibitor. In this case Ki is calculated as follows
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