Question

Eicosanoids are polyunsaturated fatty acids of _____ carbons:

• A. 30
• B. 25
• C. 15
• D. 20

Answer 1

The Correct Option is D

Eicosanoids are a group of bioactive lipid compounds derived from polyunsaturated fatty acids (PUFAs). They play a significant role in various physiological and pathological processes, such as inflammation, immunity, and acting as messengers in the central nervous system.

The most common and well-known precursor of eicosanoids is arachidonic acid, which is a polyunsaturated fatty acid containing 20 carbon atoms. Hence, eicosanoids are typically derived from PUFAs with 20 carbon atoms.

1. Analyzing the question: The question asks about the carbon count in polyunsaturated fatty acids that give rise to eicosanoids.
2. Understanding the term eicosanoids: The prefix 'eicosa-' is derived from the Greek word for twenty, "eikos," which directly indicates that these molecules are related to compounds with 20 carbon atoms.
3. Options Analysis:
   • 30: This is incorrect as 30-carbon polyunsaturated fatty acids do not typically form eicosanoids.
   • 25: This option is incorrect for similar reasons.
   • 15: This is incorrect as eicosanoids are not derived from PUFAs with just 15 carbon atoms.
   • 20: This is the correct option, as discussed and confirmed by the usual precursor, arachidonic acid, having 20 carbons.
4. Conclusion: The correct answer to the question is that eicosanoids are polyunsaturated fatty acids of 20 carbons.

Therefore, the correct answer is 20.