Table IV.
Summary of relative enzyme fluxes in oxygenated maize root tips
| Enzymes | Relative Flux | Defined Flux | Constraint |
|---|---|---|---|
| ME/PK | 0.03 ± 0.011 | Malate to pyruvate/PEP to pyruvate | None |
| PEPC/KrebsαKG→malate | 0.62 ± 0.05 | PEP to malate/α-KG to malate | None |
| PK/PEPC | 0.67a | PEP to pyruvate/PEP to malate | Synthesis of Asp only (Fig. 1) |
| PK/PEPC | 1.8b | PEP to pyruvate/PEP to malate | Synthesis of Glu only (Fig. 1) |
| PK/PEPC | 1 | PEP to pyruvate/PEP to malate | Synthesis of Asp and Glu equal |
| PEPC/ME | 20c | PEP to malate/malate to pyruvate | Synthesis of Asp only |
| PEPC/ME | 12d | PEP to malate/malate to pyruvate | Synthesis of Glu only |
| PEPC/ME | 17 | PEP to malate/malate to pyruvate | Synthesis of Asp and Glu equal |
Relative enzyme activities were either measured or deduced under specific physiological restrictions based on the results shown in Tables I–III. Errors represent se.
a
From line 2 and the relationship KrebsαKG→malate = PK + ME.
b
From line 2 and the relationship KrebsαKG→malate + PEPC = PK + ME.
c
From lines 1 to 3.
d
From lines 1, 2, and 4.