Question

Glycolipids are the major molecule involved in determining human blood types. The glycolipid for the A blood type is a different glycolipid than for the B blood type. How are these molecules produced?

A the lipid part is produced in the smooth ER; the carbohydrate part is added on the external plasma membrane

B the lipid part is produced in the rough ER; the carbohydrate part is added in the Golgi complex

C the lipid part is produced in the rough ER; the carbohydrate part is added on the external plasma membrane

D the lipid part is produced in the smooth ER; the carbohydrate part is added in the Golgi complex
a) the lipid part is produced in the smooth ER; the carbohydrate part is added on the external plasma membrane

Answer 1

Answer: D) the lipid part is produced in the smooth ER; the carbohydrate part is added in the Golgi complex

Step-by-step explanation:

Glycolipids are lipids with a carbohydrate attached by a glycosidic (covalent) bond.

Synthesis of glycolipids proceed by a series of enzymes that sequentially add sugars to the lipid. Glycosphingolipids are derived from lactosylceramide (LacCer; β-D-galactosyl(1→4)-β-D-glucosyl-ceramide) where the first step is the acylation and desaturation of D-erythro-sphinganine. Ceramide is glucosylated then β-galactosylated extracellularly to form lactosylceramide. Further elongation can occur via glycosyltransferases and sulfotransferases. For example, the biosynthesis of a major glycoglycerolipid in plants involves the transfer of a galactosyl from UDP-Gal onto diacylglycerol to produce β-galactosyldiacylglycerol via galactosyltransferases. An additional transfer of a galactosyl from UDP-Gal forms α-D-galactosyl-(1,6)-O-β-D-galactosyldiacylglycerol.