Which one is Tetraeonic (four double bond) fatty acid?

Options

A. Arachidonic acid
B. Linoleic acid
C. Oleic acid
D. Palmitic acid.

Answer

To determine which fatty acid is tetraionic (having four double bonds), we can analyze the given options: arachidonic acid, linoleic acid, oleic acid, and palmitic acid.

### Step-by-Step Solution:

1. **Understanding Fatty Acids**: Fatty acids are carboxylic acids with long aliphatic chains. They can be saturated (no double bonds) or unsaturated (one or more double bonds).

2. **Identifying the Double Bonds**: The term "tetraionic" refers to a fatty acid that contains four double bonds. We need to examine each of the options to see how many double bonds they have.

3. **Analyzing Each Option**:
- **Arachidonic Acid**: This fatty acid has four double bonds in its structure. It is classified as an omega-6 fatty acid.
- **Linoleic Acid**: This fatty acid has two double bonds. It is also an omega-6 fatty acid.
- **Oleic Acid**: This fatty acid has one double bond. It is classified as an omega-9 fatty acid.
- **Palmitic Acid**: This fatty acid is saturated and has no double bonds.

4. **Conclusion**: Among the options provided, the only fatty acid that has four double bonds is arachidonic acid. Therefore, the answer to the question is arachidonic acid.

### Final Answer:
The tetraionic (four double bond) fatty acid is **arachidonic acid**.