?

Biochemistry

Free Version

Upgrade subject to access all content

Moderate

Triacylglycerol Synthesis: Phosphatidic Acid as a Precursor

BIOCHM-@42LS2

The process of making a a triacylglycerol (TAG) from free fatty acids (FFA) involves first attaching two fatty acyl groups to a glycerol-3-phosphate backbone to make phosphatidic acid. This process then pauses before phosphatidic acid is dephosphorylated and a third fatty acyl group is added to generate the mature TAG.

What is the advantage of having phosphatidic acid as a precursor to TAG synthesis, as opposed to simply attaching three fatty acyl groups in rapid succession?

A

Phosphatidic acid serves as a scavenger of inorganic phosphate in the cell.

B

Phosphatidic acid is a form that can be easily transported across a membrane to complete the TAG generation in a different location.

C

Phosphatidic acid is a precursor for both TAGs and phospholipids; the extra step allows an opportunity for the precursor to be directed toward whichever product the cell needs most.

D

Phosphatidic acid donates its phosphate group to ADP to regenerate an ATP as the third fatty acyl group is added.

E

All of the above are correct.