In what way are fructose and glucose the same?

• A. They have the same molecular formula, \( C_6H_{12}O_6 \).
• B. They have identical structural arrangements of atoms.
• C. They are both disaccharides.
• D. They are both classified as aldoses.

Answer: (A)

Verified step by step guidance

1. Understand the question: The problem is asking about the similarities between fructose and glucose, and it provides multiple statements to evaluate. The goal is to determine which statement(s) are correct.
2. Step 1: Recall the molecular formula of fructose and glucose. Both fructose and glucose are monosaccharides, and they share the same molecular formula, which is \( C_6H_{12}O_6 \). This makes them isomers, meaning they have the same molecular formula but different structural arrangements.
3. Step 2: Evaluate the structural arrangement of atoms. Fructose and glucose differ in their structural arrangement. Glucose is an aldose (contains an aldehyde group), while fructose is a ketose (contains a ketone group). Therefore, they do not have identical structural arrangements of atoms.
4. Step 3: Determine if they are disaccharides. Fructose and glucose are monosaccharides, not disaccharides. Disaccharides are formed when two monosaccharides are joined together (e.g., sucrose is made of glucose and fructose). Thus, this statement is incorrect.
5. Step 4: Classify them as aldoses or ketoses. Glucose is classified as an aldose because it contains an aldehyde group, while fructose is classified as a ketose because it contains a ketone group. Therefore, they are not both aldoses.