Organic Chemistry MCAT Practice Exam

What can triacylglycerol be converted into through saponification?

1. Fatty acids and monosaccharides

2. Glycerol and one fatty acid

3. Glycerol and three fatty acids

4. Two phospholipids

The correct answer is: Glycerol and three fatty acids

Triacylglycerol, also known as triglyceride, is an ester derived from glycerol and three fatty acid molecules. During saponification, a reaction typically involving a strong base such as sodium hydroxide or potassium hydroxide with a triacylglycerol, hydrolysis occurs. The ester bonds between glycerol and the fatty acids are broken, resulting in the formation of glycerol and free fatty acids. Since a triacylglycerol molecule is composed of three fatty acid chains attached to a glycerol backbone, saponification will yield one molecule of glycerol and three molecules of fatty acids from one triacylglycerol molecule. This conversion is fundamental in understanding both biological systems and industrial applications, such as soap making. Other potential products of this reaction, such as monosaccharides or phospholipids, do not derive from triacylglycerol through saponification, making them incorrect choices. In summary, the correct answer reflects the stoichiometry of the reaction, as three fatty acids along with glycerol are produced specifically from the triacylglycerol structure during saponification.