How are TAGs formed from phosphatidic acid?

Triacylglycerols (TAGs) are formed from phosphatidic acid through a process that involves the removal of a phosphate group. Phosphatidic acid serves as an intermediate in lipid synthesis, specifically in the synthesis of glycerolipids.

In the formation of TAGs, phosphatidic acid, which contains a glycerol backbone linked to two acyl chains and a phosphate group, undergoes dephosphorylation. This step is typically catalyzed by a phosphatase enzyme, which removes the phosphate group, resulting in diacylglycerol (DAG). After the removal of the phosphate, an additional acyl group is added to the open hydroxyl group of the diacylglycerol. This esterification with the acyl group leads to the formation of triacylglycerol, which is stored in adipose tissue and serves as an important energy reserve in the organism.

Thus, option B accurately describes the biochemical process of TAG formation from phosphatidic acid through the dual steps of dephosphorylation and subsequent acylation. This pathway is essential for lipid metabolism and energy storage in biological systems.