Q. 15.17 - An Introduction to General, Organic, and Biological Chemistry

Question

What is the difference in the location of the first double bond in an omega-$3$ and an omega-$6$-fatty acid (see Chemistry Link to Health "Omega-$3$-Fatty Acids in Fish Oils")?

Step-by-Step Solution

Answer

• Linolenic acid is an omega-$3$-fatty acid, with its initial double bond at carbon $3$.
• Linoleic acid is an omega-$6$-fatty acid, with its initial double bond at carbon $6$.

Step 1: Introduction

• Saturated and unsaturated fatty acids are the two types available. 
• Unsaturated fatty acids are formed when a lengthy chain of carboxylic acids contains double or triple bonds. 
• A fatty acid chain is said to be saturated when it contains all of the single bonds in its structure.

Step 2: Explanation for Omega-3

• A double bond exists on carbon $3$ counting the methyl group in an omega-3 fatty acid. 
• Linolenic acid is an omega-$3$ fatty acid, with its initial double bond at carbon $3$.

Step 3: Explanation for Omega-6

• A double bond starts at carbon $6$ counting from the methyl group in an omega-6 fatty acid.
• Linoleic acid is an omega-$6$ fatty acid, with its initial double bond at carbon $6$.