Saturated fatty acids are all except?

Appeared in: NCL (MP) Nursing Officer - 2019

Explanation

Oleic acid is classified as a monounsaturated fatty acid, not a saturated one.
Its chemical structure includes an 18-carbon chain with one carbon-carbon double bond (denoted as 18:1).
Saturated fatty acids, by definition, lack any carbon-carbon double bonds in their hydrocarbon tail.
Since the question asks for the exception among saturated fatty acids, oleic acid is the correct answer.

Option A: Lauric acid is a classic example of a saturated fatty acid. It has a 12-carbon chain with no double bonds (12:0).
Option B: Palmitic acid is one of the most common saturated fatty acids found in animals and plants. It consists of a 16-carbon chain with no double bonds (16:0).
Option C: Stearic acid is a saturated fatty acid with an 18-carbon chain and no double bonds (18:0). It is commonly found in animal and vegetable fats.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of fatty acids as background academic context rather than a clinical decision trigger.
Understanding the difference between saturated and unsaturated fats is crucial for patient dietary education, especially for managing cardiovascular health.
Diets high in saturated fats (found in butter, ghee, fatty meats) are associated with increased levels of LDL ('bad') cholesterol, a risk factor for atherosclerosis.
Monounsaturated fats like oleic acid (abundant in olive oil, canola oil, and avocados) can help lower LDL cholesterol and raise HDL ('good') cholesterol, promoting heart health.

How to Approach the Question

First, identify the core concept of the question, which is 'saturated fatty acids'.
Recall the definition: Saturated fatty acids are hydrocarbon chains with only single bonds between carbon atoms.
The keyword 'except' signals that you must find the option that does NOT fit this definition.
Evaluate each option based on this definition. Lauric, Palmitic, and Stearic acids are all saturated fats.
Identify Oleic acid, which has one double bond, as the one that is different (it is monounsaturated).
Therefore, Oleic acid is the correct answer as it is the exception.

Concept Tested & Keywords

Concept Tested: Classification of fatty acids
Stem keywords: Saturated fatty acids
Lead-in keywords: except
Negative lead-in flag: The question asks to identify the option that is NOT a saturated fatty acid.

Q0j3UMd7Zii7yUAw1bPbCi

E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart A (pp 1-232 of 464) p. 145-147

Practise the full NCL (MP) Nursing Officer - 2019

Attempt every question from this paper in a timed mock, then review the full solution for each one.