Which disaccharide is joined by an \(\alpha(1\rightarrow4)\) glycosidic bond?

• A. Lactose
• B. Maltose
• C. Cellobiose
• D. Sucrose

Answer: (B)

Verified step by step guidance

1. Understand the structure of a glycosidic bond: An \( ext{α}(1 ightarrow4)\) glycosidic bond connects the anomeric carbon (carbon 1) of one sugar molecule in the alpha configuration to the hydroxyl group on carbon 4 of another sugar molecule.
2. Review the structures of the disaccharides provided: Lactose, Maltose, Cellobiose, and Sucrose. Each disaccharide has a unique glycosidic bond type and sugar composition.
3. Analyze Maltose: Maltose is composed of two glucose molecules joined by an \( ext{α}(1 ightarrow4)\) glycosidic bond. This bond specifically connects the anomeric carbon of the first glucose (in the alpha configuration) to the hydroxyl group on carbon 4 of the second glucose.
4. Compare the glycosidic bonds in the other disaccharides: Lactose has a \(eta(1 ightarrow4)\) glycosidic bond, Cellobiose has a \(eta(1 ightarrow4)\) glycosidic bond, and Sucrose has an \( ext{α}(1 ightarrow2)\) glycosidic bond.
5. Conclude that Maltose is the correct answer because it is the only disaccharide in the list joined by an \( ext{α}(1 ightarrow4)\) glycosidic bond.