Question

Eicosanoids are a type of polyenoic fatty acids that consist of
(A). Leukotrienes
(B). Prostaglandins
(C). Lipoxins
(D). Cholesterol
Choose the correct answer from the options given below:

• A. (A), (B) and (D) only
• B. (A), (B) and (C) only
• C. (A), (C) and (D) only
• D. (B), (C) and (D) only

Hint:

Remember that eicosanoids are all about inflammation and signaling, and they come from 20-carbon fatty acids like arachidonic acid. The key families are prostaglandins, leukotrienes, thromboxanes, and lipoxins. Cholesterol is a sterol with a completely different ring structure.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Eicosanoids are a family of signaling molecules derived from the oxidation of 20-carbon polyunsaturated fatty acids (PUFAs), most notably arachidonic acid. The name "eicosanoid" comes from the Greek "eikosi" meaning twenty. They act as local hormones, regulating many physiological processes like inflammation, fever, blood pressure, and blood clotting.
Step 2: Detailed Explanation:
Let's analyze the given options:
(A) Leukotrienes: These are a major class of eicosanoids produced primarily by leukocytes. They are involved in inflammatory and allergic reactions. They are derived from arachidonic acid via the lipoxygenase pathway.
(B) Prostaglandins: These are another major class of eicosanoids found in almost every tissue in humans. They have diverse hormone-like effects. They are derived from arachidonic acid via the cyclooxygenase (COX) pathway.
(C) Lipoxins: These are eicosanoids that are involved in the resolution of inflammation. They are also derived from arachidonic acid.
(D) Cholesterol: This is a sterol, a type of lipid characterized by a four-ring steroid nucleus. It is a vital component of animal cell membranes and a precursor for steroid hormones, but it is structurally and biosynthetically distinct from eicosanoids and is not derived from a 20-carbon fatty acid.
Step 3: Final Answer:
Leukotrienes, prostaglandins, and lipoxins are all types of eicosanoids. Cholesterol is not. Therefore, the correct group is (A), (B), and (C).