Question

Which one of the following combinations of all three fatty acids are essential for human beings?
(a) Oleic acid, linoleic acid and linolenic acid
(b) Palmitic acid, linoleic acid and linolenic acid
(c) Oleic acid, linoleic acid and arachidonic acid
(d) Linoleic acid, linolenic acid and arachidonic acid

Answer 1

Hint: Essential fatty acids are the fatty acids that we require for good health and proper functioning, but the body cannot synthesize them. They include certain unsaturated fatty acids and polyunsaturated fatty acids. They are present in the phospholipids and hence are integral for the cell membranes.

Complete Step by Step Answer:
Unsaturated fats at room temperature are in liquid state and have double bonds. The unsaturated fatty acids that are not synthesized by the body but are necessary for its functioning are called essential fatty acids. The human body cannot introduce double bonds in fatty acids beyond carbon 9 and 10 of the long-chain fatty acids. This is the reason the unsaturated fatty acids need to be supplemented from outside.
They include linoleic acid and alpha- linolenic acid which are unsaturated and have double bonds. The essential fatty acids also include a polyunsaturated omega- 6 fatty acid, the arachidonic acid. All these fatty acids are present in the phospholipids and help in the formation of body membranes.
So, the correct answer is, “Linoleic acid, linolenic acid, and arachidonic acid.”

Note:
- Arachidonic acid is considered to be essential as it cannot be synthesized in the human body directly, i.e., de novo synthesis is not seen. However, it can be synthesized from linoleic acid if it is present in sufficient quantities.
- Arachidonic acid however is required in huge quantities as it is the major precursor of the prostaglandins and leukotrienes, that play a major role in cell signalling. Owing to these factors, it is considered essential and recommended to be supplemented in the required amount in the diet. Sometimes it is also termed as a conditionally essential fatty acid.