Question

The structural lipids of cell membrane are
A)Simple lipid
B)Chromolipids
C)Steroid
D)Phospholipids

Answer 1

Hint: Cell membrane is also known as Plasma membrane and it is also defined as biological membrane where it separates the interior of the cell and component to the exterior or outside, or from the environment, and this membrane is form up of a various number of components.

Complete answer:
The cell membrane is mainly made up of three types of amphipathic lipids, they are phospholipids, glycolipids, and sterols. The percentage of different types of lipids differs from cell to cell, in a greatest number of the cells, the abundant one is phospholipids which constitutes 50% of all, and glycolipids form only 2% and the rest is formed by the sterols.

Now let us find solution from given options:
Simple lipid : A simple lipid is usually defined as a fatty acid ester of different alcohols and carries no other substance. These lipids generally show its relation to a heterogeneous class of predominantly nonpolar compounds, mostly insoluble in water, but it is soluble in nonpolar organic solvents such as chloroform and benzene.
Chromolipids : it is normally defined as pigmented lipids. Examples may include carotene.

They are major constituents in photosynthesis but not in the cell membrane.
Steroid : A steroid is defined as a biologically active organic compound that consists of four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes but are present in only 2% amount which alter membrane fluidity; and as signalling molecules.
Phospholipids : Phospholipids are major constituents of cell membrane because they can form bilayers in water. Studies have observed that the cell membrane is majorly composed of lipids and proteins. The most important lipids present are phospholipids which are arranged in a bilayer.

Hence, the correct answer is option (D)

Note: Phospholipids that are present within the cell membrane are formed by two hydrophobic fatty acid tails and a hydrophilic head. There is a phosphate group that remains connected to the hydrophilic head. The two hydrophobic and hydrophilic portions are linked by a molecule of glycerol.