Question

Which one the following is not a monosaccharide?

• A. Glucose
• B. Fructose
• C. Rhamnose
• D. Maltose

Hint:

Common disaccharides to remember for biochemistry questions are Maltose (Glucose + Glucose), Lactose (Glucose + Galactose), and Sucrose (Glucose + Fructose).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Carbohydrates are classified based on their structural complexity into monosaccharides (simple sugars), disaccharides (two sugar units), and polysaccharides (complex chains).

Step 2: Detailed Explanation:
- Glucose: An aldohexose monosaccharide ($\text{C}_6\text{H}_{12}\text{O}_6$).
- Fructose: A ketohexose monosaccharide ($\text{C}_6\text{H}_{12}\text{O}_6$).
- Rhamnose: A naturally occurring deoxy-monosaccharide ($\text{C}_6\text{H}_{12}\text{O}_5$).
- Maltose: A disaccharide formed by a condensation reaction between two $\alpha$-D-glucose molecules linked by an $\alpha(1\rightarrow4)$ glycosidic bond.
Therefore, Maltose is not a monosaccharide.

Step 3: Final Answer:
Maltose is a disaccharide, not a monosaccharide.