Page 279 - Thermodynamics of Biochemical Reactions

Thermodynamics of Biochemical Reactions at Specified pH 279

-2292.5

calcdQRat[atpspl/.pH->7/.is->.25
-2292.5

This illustrates the convenience of the program calcdGmar..

(c) When the package BasicBiochemData2 is loaded, typing atp yields a function of pH and ionic strength as we have
seen in (b).

Plot [ atp/ . is- > .25, {pH, 5,9}, AxesLabel-> { "pHtl, I*\ ! \ (TraditionalForm\. \ (A\-r\ ) G ' \ "o\ ) I' 1 1 ;

A, G"

(d) Equation 4.7-3 shows that the average number of hydrogen atoms in a reactant is given by (lRTln(l0)) times the
derivative of the standard transformed Gibbs energy of the reactant. First we calculate the function of pH at ionic strength
0.25 M

-PH
-0.403393 (-2830.08 - 34.7056 Log[lO
-2.47897 Log [E I) +
-PH
-0.403393 (-2808.24 - 32.2266 LOg[lO
E I) +
-PH
-0.403393 (-2771.34 - 29.7477 LOg[lO
E ]'I