Phospholipid Metabolism

Phospholipid Metabolism

Functions:

1. Enter in structure of cell membrane and thus affects its permeability.

2. Enter in structure of myelin sheath of nerve, sphingomyleins act as electric insulator, so play a role in nerve impulse condition.

3. In mitochondria it is an important component of respiratory chain enzyme.

Phospholipid Metabolism

Functions:

4. Dipalmityl lecithin is a surface-active agent (surfactant) which prevent collapse of lung alveoli.

5. Inositol phospholipids in the cell membrane act as precursors of hormone second messenger as upon stimulation by hormone → cleavage to diacylglycerol and inositol triphosphate and both are second messengers.

1-Phosphoglycerides

1-Phosphoglycerides

Cardiolipin

It is a diphosphatidyl glycerol formed of 2 phosphatidic acids attached together by glycerol.

• Functions of cardiolipin

– Cardiolipin is present in heart muscle.

– It is used as antigen for detection of syphilis.

Shpingolipid synthesis

( dihydrosphingosine)

2H

Catabolism of Phosphoglycerides

Phospholipase A1

Phospholipase A2

FFA

Lysophospholipid

H

H

Lysophospholipid

Phospholipase B

Phospholipase B

H

H

FFA

FFA

FFA

Glycerophosphoryl base

H

H

Hydrolase H

H

Nitrogenous

base Glycerol 3 p Glycerophosphoryl base