Page 327 - Thermodynamics of Biochemical Reactions

Systems of Biochemical Reactions 327

1 2 3 4
Glc -1 0 0 0
Pi -2 0 -1 -3

ADP -2 0 -1 -3
NADox -2 -1 -4 1
PYr 2 -1 0 0
ATP 2 0 1 3

NADred 2 1 4 -1
H2 0 2 0 -2 4
CoA 0 -1 1 0
acetylCoA 0 1 -1 0

c02 0 1 2 0
1
- (-)
02 0 0 0 2

mkeqm[c-List,s-List]:=(*c-List is the list of stoichiometric numbers for a reaction.
s-List is a list of the names of species or reactants. These names have to be gut in
quotation marks. * )Mag [Max [#, 01 &, -cl . s->Mag [Max [#, 0 I &, cl . s

nameMatrix[m~List,s~Listl:=(*m~List is the transposed stoichiometric number matrix for
the system of reactions. s-List is a list of the names of species or reactants. These
names have to be gut in quotation marks.*)Map[mkeqm[#,sl&,ml

nameMatrix[Transgose~nu~~ ,names1
{2 ADP + Glc + 2 NADox + 2 Pi -> 2 ATP + 2 H20 + 2 NADred + 2 Pyr,
CoA + NADox + Pyr -> acetylCoA + C02 + NADred,
acetylCoA + ADP + 2 H20 + 4 NADox + Pi -> ATP + 2 C02 + CoA + 4 NADred,

3 ADP + NADred + - + 3 Pi -> 3 ATP + 4 H20 + NADox}
2
As indicated in equation 6.2-2 the stoichiometric numbers for the net reaction are given by

nunet={-1,-40,-40,0,0,46,0,0,6,0,0r6,-61
{-I, -40, -40, 0, 0, 40, 0, 46, 0, 0, 6, -61

The pathway can be calculated by use of

Thus to oxidize a mole of glucose to carbon dioxide and water, reaction 1 has to occure once, reaction 2 has to occur twice,
reaction 3 has to occur twice, and reaction 4 has to occur 12 times.

6.3 (a) Type in the stoichiometric number matrix for glycolysis at a specified pH that is given in Fig. 6.1. (b) Use nameMa-
trix to type out the 10 reactions. (c) Use equation 6.1-3 to calculate the net reaction for glycolysis. (d) Calculate a basis for
the conservation matrix for glycolysis and row reduce it to determine the number of components.