Question

write the composition of plasma membrane??​

Answer 1

Answer:

The plasma membrane is composed of a phospholipid bilayer, which is two layers of phospholipids back-to-back. Phospholipids are lipids with a phosphate group attached to them. The phospholipids have one head and two tails. Located all throughout the surface of the plasma membrane are cholesterol molecules.

Answer 2

Answer:

Chemical Composition of Plasma Membrane:

The membrane is mainly composed of lipids, proteins and carbohydrates. Water makes about 29% of total weight. Robertson (1959) proposed that plasma membrane is three-layered structure where proteins form the outer and inner layers of membrane that encloses lipids to form a unit membrane.

i. Lipid:

The lipids identified in the plasma membrane consist of cholesterol, phospholipids and galactolipids. The phospholipids include phosphatidylcholine, phosphatidylethanolamine and sphingomyelin. The phospholipids are found to be associated with the outer protein shell in the plasma membrane. Glycerol and fatty acid constitute lipid molecules.

ii. Protein:

In the membrane it is present as enzyme protein, carrier protein and structural protein. The enzyme proteins have catalytic activity. The carrier proteins help to transport materials in and out of the cell across membrane. The structural proteins play an important role to form the structure of membrane.

iii. Carbohydrates:

They occur in the form of glycolipids and glycoproteins. Both of these forms are confined exclusively to the external membrane surface. Bell (1962) is of opinion that polysaccharides confer some stability to the lipoprotein complex in the membrane.

Origin of Plasma Membrane:

Bell suggested that the phragmosomes, those appear during middle lamella formation and are composed of polysaccharides, help in the formation of new plasma membrane on reaction with lipoprotein.

HOPE THIS INFO WILL HELP YOU

MARK IT AS BRAILNLIEST

THANKS