Question

Explain why insulin is required for adipocytes to synthesize triacyl-

glycerol from fatty acids.

Short answer

The production of triglycerols depends on insulin as glucose starts the production of glycerol-3-phosphate.

Step-by-step solution

Adipocytes

Adipocytes, also known as lipocytes or fat cells, are the cells that make up adipose tissue and are responsible for storing energy in the form of fat. Adipocytes are produced from mesenchymal stem cells that undergo adipogenesis to become adipocytes.

Production of Triacylglycerol

The esterification of acyl-CoA a with glycerol-3-phosphate forms acyl-CoA enzymefrom the fatty acid, and triacylglycerols are produced. While Dihydroxy acetone phosphate is reduced to produce glycerol-3-phosphate, the latter is produced by glycolysis from glucose.

Use of insulin 

Insulin is a hormone that causes the cells to take in glucose. It increases the activity of the insulin-sensitive glucose transporter GLUT4 on adipocyte surfaces.

Thus, insulin is required by adipocytes for triacylglycerol synthesis.