Essential fatty acid is ?
**Core Concept**
Essential fatty acids (EFAs) are polyunsaturated fatty acids that cannot be synthesized by the human body and must be obtained through the diet. They play a crucial role in various physiological processes, including inflammation regulation, cell membrane structure, and hormone production.
**Why the Correct Answer is Right**
The correct answer is linoleic acid, an omega-6 fatty acid, and alpha-linolenic acid, an omega-3 fatty acid. These EFAs are essential for maintaining the integrity of cell membranes, regulating inflammation, and supporting brain function. They are also precursors to prostaglandins, which are hormone-like substances involved in various physiological processes.
**Why Each Wrong Option is Incorrect**
**Option A:** Arachidonic acid is a polyunsaturated fatty acid but not an essential one, as it can be synthesized from linoleic acid in the body.
**Option B:** Palmitic acid is a saturated fatty acid and is not classified as an essential fatty acid.
**Option C:** Oleic acid is a monounsaturated fatty acid and is not considered an essential fatty acid.
**Clinical Pearl / High-Yield Fact**
Remember that essential fatty acids have a 2:1 ratio in the diet, with a minimum of 2 grams of alpha-linolenic acid for every 1 gram of linoleic acid to maintain optimal health.
**Correct Answer: D. Linoleic acid and alpha-linolenic acid**