Question

Hi,
I have a question concerning lipid metabolism. Via various enzymes triglycerides are converted into fatty acids, which undergo beta oxidation. The remaining glycerol is incorporated into gluconeogenesis. My question is, how does glycerol end up in gluconeogenesis, i. e. which enzymes, steps etc. are necessary.

Thanks in advance!

Answer 1

Well first of all glycerol can both enter the gluconeogenic- or glycolytic pathway depending on the metabolic circumstances.

But this is how it happens:
*Glycerol is made into glycerol phosphate by glycerol kinase.
*Glycerol phosphate is made into dihydroxyacetone phosphate by glycerol phosphate dehydrogenase.
*Dihydroxyacetone phosphate is then made into glyceraldehyde-3-phosphate by triose phosphate isomerase.

And as you know glyceraldehyde-3-phosphate is a intermediate in the glycolysis and gluconeogenesis.