Which carbohydrate is most commonly found in the body?

• A. Glycogen and mucin
• B. Glucose
• C. Fructose
• D. Sucrose

Answer: (A)

The main idea here is recognizing what form of carbohydrate is most pervasive in the body. Glycogen is the primary storage form of glucose in liver and muscle, providing the largest immediate reservoir of carbohydrate. Mucin is a major glycoprotein secreted in mucus, and its carbohydrate-rich glycan portions are widespread in body secretions and tissues. Together, these represent the most commonly encountered carbohydrate-containing substances in the body, more so than free glucose circulating in blood or the dietary sugars fructose and sucrose, which aren’t resident in large amounts in tissues. So glycogen and mucin best reflect what’s most abundant in the body.