TAG Synthesis

Triacylglycerol Synthesis Step 1

DHAP from glycolysis is reduced by glycerol-3-phosphate dehydrogenase (uses NADH) → glycerol-3-phosphate, the main glycerol backbone.

Triacylglycerol Synthesis Step 2

GPAT (glycerol-3-phosphate acyltransferase) esterifies the first fatty acyl-CoA onto glycerol-3-phosphate → lysophosphatidic acid. CoA is released.

Triacylglycerol Synthesis Step 3

LPAT (lysophosphatidic acid acyltransferase) adds a second acyl-CoA → phosphatidic acid. Phosphatidic acid can branch to phospholipid synthesis (via CTP) or continue to TAG.

Triacylglycerol Synthesis Step 4

PAP (phosphatidic acid phosphohydrolase) removes the phosphate → diacylglycerol (DAG).

Triacylglycerol Synthesis Step 5

DGAT (diacylglycerol acyltransferase) esterifies a third acyl-CoA onto DAG → triacylglycerol. TAGs are stored in lipid droplets enclosed by a phospholipid monolayer and perilipins, primarily in adipose tissue.