Análise da Hidrolise do ATP

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SOLUTIONSMANUAL TO ACCOMPANY ATKINS' PHYSICAL CHEMISTRY 209
De�ning (b/b−○)1/2 as x and the le�-hand side as y, and introducingA = 0.5091
gives
y = 1.0182x
1 + Bx
− 2Cx2 − 2 log x + pKa
which is �tted to the data usingmathematical so�ware to give the following val-
ues for the parameters: B = 2.54 , C = −0.204 , and pKa = 6.74 .�ese values
have been used to draw the line on the graph shown in Fig. 6.5.
b/mmol kg−1 Ecell/V (b/b−○)1/2 y
0.01 0.744 52 0.100 8.823 73
0.02 0.728 53 0.141 8.553 44
0.03 0.719 28 0.173 8.397 08
0.04 0.713 14 0.200 8.293 30
0.05 0.708 09 0.224 8.207 94
0.06 0.703 80 0.245 8.135 42
0.07 0.700 59 0.265 8.081 16
0.08 0.697 90 0.283 8.035 69
0.09 0.695 71 0.300 7.998 67
0.10 0.693 38 0.316 7.959 29
0.05 0.10 0.15 0.20 0.25 0.30 0.35
8.0
8.2
8.4
8.6
8.8
(b/b−○)1/2
F(
E c
el
l−
E−
○ ce
ll)
/R
T
ln
10
Figure 6.5
I6.8 From Impact 9 the reaction for the hydrolysis of ATP to ADP and inorganic
phosphate P−i is
ATP(aq) +H2O(l)→ ADP(aq) + P−i (aq) +H3O+(aq)
Under biological standard conditions, that is, pH = 7, the standard reaction
Gibbs energy at 37 ○C is given in Impact 9 as ∆rG⊕ = −31 kJmol−1.