Question

Monounsaturated fatty acids have a single double bond. Polyunsaturated fatty acids have multiple double bonds. Which of the following statements is true?

A. Monounsaturated fatty acids store more energy than polyunsaturated fatty acids.

B. Polyunsaturated fatty acids store more energy than monounsaturated fatty acids.

C. Polyunsaturated fats have a lower melting point than monounsaturated fatty acids.

D. Monounsaturated fats have a lower melting point than polyunsaturated fatty acids.

Answer 1

The right answer is option C - polyunsaturated fats have a lower melting point than monounsaturated fatty acids.

Explanation :-

• Polyunsaturated fatty acids (PUFA) have more than one double bond in the fatty acid chain that forms the backbone. Now, it is a known fact the melting temperature of fatty acids increases with the decrease in the number of double bonds in the fatty acid chain. Hence, the monounsaturated fatty acids (MUFA) have a higher melting point than polyunsaturated fatty acids. Therefore, option C is right and option D (which tells the reverse) is wrong.
• When it comes to storage of energy, unsaturated fats as a common group generally store less energy as compared to saturated fats. Now, if the unsaturated fats are further classified into PUFA and MUFA, it cannot be accurately said which one of them stores lower energy. Therefore, we can safely conclude that option C is the most accurate answer.