Which of the following statement is not correct?

Options

A. Arachidonic acid has 20 carbon atoms excluding the carboxyl carbon
B. Palmitic acid has 16 carbon atoms
C. Stearic acid is saturated fatty acid
D. All are correct

Answer

To determine which statement is not correct, we will analyze the given options one by one based on the information provided in the video transcript.

### Step-by-Step Solution:

1. **Understanding Arachidonic Acid**:
- Arachidonic acid is an unsaturated fatty acid.
- It contains 20 carbon atoms, excluding the carboxyl carbon.
- It has 4 double bonds.

2. **Analyzing Palmitic Acid**:
- Palmitic acid is a saturated fatty acid.
- It contains 16 carbon atoms.

3. **Analyzing Stearic Acid**:
- Stearic acid is also a saturated fatty acid.
- It contains 18 carbon atoms.

4. **Comparison of Statements**:
- The first statement about arachidonic acid is correct: it has 20 carbon atoms (excluding the carboxyl carbon) and is unsaturated with 4 double bonds.
- The statements about palmitic acid and stearic acid are also correct: palmitic acid has 16 carbons and stearic acid has 18 carbons, both being saturated.

5. **Identifying the Incorrect Statement**:
- Since all the statements regarding arachidonic acid, palmitic acid, and stearic acid are correct, we need to check if there are any other statements provided in the options that might not be correct.
- If there are no other statements provided, then we conclude that all the given statements are correct.

### Conclusion:
After analyzing the statements, if all provided statements are correct, then there is no incorrect statement among the options given.