Which two monosaccharides combine to form sucrose?

• A. $\mathrm{Glucose}$ and $\mathrm{fructose}$
• B. $\mathrm{Glucose}$ and $\mathrm{galactose}$
• C. $\mathrm{Glucose}$ and $\mathrm{ribose}$
• D. $\mathrm{Fructose}$ and $\mathrm{galactose}$

Answer: (A)

Verified step by step guidance

1. Understand that sucrose is a disaccharide, which means it is composed of two monosaccharide units.
2. Recall that the most common monosaccharides involved in forming disaccharides are glucose, fructose, and galactose.
3. Identify that sucrose is specifically formed by the combination of glucose and fructose.
4. Recognize that the glycosidic bond in sucrose is formed between the anomeric carbon of glucose and the anomeric carbon of fructose.
5. Eliminate the other options by verifying that glucose and galactose form lactose, and glucose and ribose do not typically form a common disaccharide.