Question

Which of the following fatty acids is an omega \((\omega)\)-3 fatty acid?

• A. 18:3 \((\Delta^{3,9,12})\)
• B. 18:1 \((\Delta^{9})\)
• C. 18:2 \((\Delta^{9,12})\)
• D. 18:3 \((\Delta^{9,12,15})\)

Hint:

Omega-3: first double bond at C3 from methyl end.
Example: \(\alpha\)-linolenic acid (18:3, \(\Delta^{9,12,15}\)).
Omega-6: first double bond at C6 from methyl end.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Omega-3 fatty acids have a double bond at the third carbon from the methyl end.
The position of the double bond determines the omega designation.

Step 2: Key Formula or Approach:
No specific formula.
Need to know the structure of omega-3 fatty acids.

Step 3: Detailed Explanation:
Omega-3 fatty acids have the first double bond at carbon 3 from the omega (methyl) end.
For 18:3 \((\Delta^{9,12,15})\), the double bonds are at positions 9, 12, and 15.
Counting from the methyl end, the first double bond is at carbon 3 (18 - 15 = 3).
Thus, it is an omega-3 fatty acid.
Other options do not have the omega-3 configuration.

Step 4: Final Answer:
18:3 \((\Delta^{9,12,15})\) is an omega-3 fatty acid.
Hence, the correct option is (D).