Answer:
Arachidonic Acid and PGE₁ are both carboxylic acids with Twenty Carbon atoms. The differences are that Arachidonic acid contains Four cis Double Bonds and no other functional groups, whereas PGE₁ has One Trans Double Bond, Two Hydroxyl and One Ketone Functional Groups.. In addition, a part of the PGE₁ chain forms a Five Membered Ring.
Structures of Both Arachidonic Acid and PGE₁ are shown Below,
