1. Gluconeogenesis

3. Gluco
neo
genesis
Standard
free
energies

4. Gluco
neo
genesis
Working
free
energies

5. Gluconeogenesis starts in the mitochondrion

6. ..and finishes up in the endoplasmic reticulum (to release glucose).

7. - + -- -- +- - + Why control? Note possible futile cycle:
F1,6BP + H2O ->
F6P + Pi
F6P + ATP ->
F1,6BP + ADP
Net:
ATP + H2O ->
ADP + Pi + -- -- +- - +

8. While animals can use many amino acids to make
glucose, they cannot use acetyl-CoA from fatty
acid breakdown.
Removing malate from the TCA cycle means that
there is a lack of OAA to form citrate.
But plants and bacteria can convert acetyl-CoA to
glucose using the glyoxylate cycle.

9. make carbohydrates from fats.
A modification of the TCA cycle (glyoxylate cycle) lets plants and bacteria
make carbohydrates from fats.
to glucose
isocitric lyase
malate synthase

10. Starch/glycogen
synthesis

11. PPP:
Pentose
Phosphate
Pathway

12. PPP:
Pentose
Phosphate
Pathway
P-pentose
isomerase TK TK TA
epimerase

13. Using the PPP
to make NADPH

14. Using the PPP
to make ribose

15. Summary
Synthesis of glucose from pyruvate involves the glycolytic pathway
plus 4 new enzymes.
Glycolysis and gluconeogenesis show reciprocal controls to
prevent futile cycles.
Plants can direct acetyl-CoA to gluconeogenesis with the glyoxylate
cycle.
Starch/glycogen synthesis involves UDPG (ADPG).
Pentose phosphate pathway provides a method for synthesizing
NADPH and ribose, among other compounds.