Function of phospholipid in cell membrance | Crack PGIMER 22 MAY 2016

Function of phospholipid in cell membrance is 

A. Cell to cell variation
B. Transduction of Signals
C. Transmembrane preparation of protein
D. DNA replication
E. Enzyme activation at membrane surface

The Answer is. (B) Transduction of Signals (E) Enzyme activation at membrane surface:

• Cell membrane phospholipids have the following functions

—Along with cholesterol it forms bilipid layer which is permeable to water, maintain fluidityof the membrane, some molecules like 0₂, N₂ dissolve in bilipid layer and cross with ease.

— Signal transduction the phosphorylation of membrane bound phosphatidyl inositol occurs in response to variety of neurotransmitters, hormones and growth factors to the receptors on the cell-membrane. The degradation of these polyphosphatidyl inositol result in mobilisation of intracellular calcium and activation of protein kinase C. Both of which synergistically act to evoke specific cellular response.

— Specific proteins (alk.phosphatase, acetyl cholinesterase) can be covalently attached via carbohydrate bridge to the membrane bound P1, phosphatidyl inositol.

• The proteins are arranged in transmembrane (integral protein) and also peripherally

• Cell to cell variation found in case of membrane proteins

• Proteins function as: cell adhesion, carriers, ion-channels, receptors, enzymes

• DNA replication occurs in nucleus.