True about conversion of 20C fatty acid conversion to prostaglandin synthase

Biosynthesis of Prostaglandins Prostaglandins are derived from the PUFA, the three series being derived from the following fatty acids. 1 series (1 double bond) -from Linoleic acid 2 series (2 double bonds)-from Arachidonic acid 3 series (3 double bonds)-Eicosa Penta-enoic Naturally occurring PGs belong to the 2 series. i. PGs are not stored as such; the precursor fatty acids are stored in membrane as phospholipids. The arachidonic acid is released by the action of phospholipase A2 on phospholipids (Fig. 13.3). ii. Synthesis is catalyzed by Prostaglandin H synthase (PGHS). It contains two separate enzyme activities, cyclo-oxygenase, and peroxidase. iii. PGG2 and PGH2 are formed as intermediates during the synthesis of other PGs. Specific enzymes conve PGH2 to other prostaglandinsRef: DM Vasudevan - Textbook of Biochemistry, 8th edition, page no: 164