Table 2 Energetic (ATP and NAD(P)H) requirements for the synthesis of TAG and storage carbohydrate per unit carbon

TAG synthesis partial reactions:

3 CO₂ → 3-phosphoglyceraldehyde→ acetylCoA

12 ATP, 4 NAD(P)H + CO₂

AcetylCoA_(n-1used) mediated fatty acid elongation (e.g., C16:0)

7 ATP + 14 NADH

Fatty acid desaturation

1 NADH equivalent/bond desaturated

3 CO₂ → Glycerol

9 ATP + 7 NAD(P)H

TAG (C ₅₅ H ₉₈ O ₆ ) synthesis summary:

26 acetyl CoA =

312 ATP, 104 NAD(P)H

Fatty acid elongation C16:0 + 2 C18:0 =

23 ATP, 46 NAD(P)H

4 desaturations

4 NAD(P)H equivalents

1 glycerol

9 ATP, 7 NAD(P)H

Total

344 ATP, 160 NAD(P)H

Per carbon

6.25 ATP, 2.93 NAD(P)H

Starch /glycogen synthesis partial reactions:

6 CO₂ → 2 3-phosphoglyceraldehyde → glucose

24 ATP, 12 NAD(P)H

Glucose → storage carbohydrate

1 ATP/glucose

Starch synthesis (55 units, 330 C) summary:

Total for 55 glucose

1375 ATP, 660 NAD(P)H

Per Carbon

4.16 ATP, 2 NAD(P)H