Question

Glycolipids in the plasma membrane are located at

• A. Inner leaflet of the plasma membrane
• B. The outer leaflet of the plasma membrane
• C. Evenly distributed in the inner and outer leaflets
• D. It varies according to cell types

Answer 1

Answer: (B)

In eukaryotes, the cell membrane is explained as a fluid mosaic model by Schleiden and Schwann. According to this model the plasma membrane is made up of lipids and proteins. The lipids are arranged in a bilayer. The lipids present are phospholipids. These are arranged in such a way that the polar heads are towards the outer side and hydrophobic ends are towards the inner side. The ratio of proteins and lipids are different in different cell types. In humans it is seen that around 40 percent is lipid and 52 percent is protein. This explains that the quasi- fluid nature of lipid causes the movement of proteins throughout the bilayer structure. The glycolipids are oriented towards outside the plasma membrane and are extrinsic in nature.