Which of the following is not a carbohydrate?

Which of the following is not a carbohydrate?

• A. Glucose
• B. Fructose
• C. Glycerol
• D. Ribose

Answer: (C)

Carbohydrates are sugars built from carbon, hydrogen, and oxygen, typically with (CH2O)n structure, and they include simple sugars like glucose and fructose as well as ribose, a five-carbon sugar used in nucleic acids. Glucose and fructose are both monosaccharides, compact sugar units, and ribose is a sugar integral to RNA and other biomolecules. Glycerol, on the other hand, is a three-carbon alcohol with three hydroxyl groups and no carbonyl group or saccharide ring. It is a component of lipids (as the backbone of triglycerides and phospholipids) rather than a carbohydrate. This is why glycerol is not a carbohydrate.

Carbohydrates are sugars built from carbon, hydrogen, and oxygen, typically with (CH2O)n structure, and they include simple sugars like glucose and fructose as well as ribose, a five-carbon sugar used in nucleic acids. Glucose and fructose are both monosaccharides, compact sugar units, and ribose is a sugar integral to RNA and other biomolecules. Glycerol, on the other hand, is a three-carbon alcohol with three hydroxyl groups and no carbonyl group or saccharide ring. It is a component of lipids (as the backbone of triglycerides and phospholipids) rather than a carbohydrate. This is why glycerol is not a carbohydrate.