Which functional groups are present in all monosaccharides?

• A. Phosphate and methyl groups
• B. Carboxyl and amino groups
• C. Hydroxyl and carbonyl groups
• D. Sulfhydryl and ester groups

Answer: (C)

Verified step by step guidance

1. Step 1: Begin by understanding the structure of monosaccharides. Monosaccharides are the simplest form of carbohydrates and are composed of carbon, hydrogen, and oxygen atoms.
2. Step 2: Recall the functional groups commonly found in monosaccharides. These include hydroxyl groups (-OH) and carbonyl groups (C=O). The hydroxyl group is a characteristic feature of alcohols, while the carbonyl group is found in aldehydes and ketones.
3. Step 3: Differentiate between the types of monosaccharides based on the position of the carbonyl group. If the carbonyl group is at the end of the carbon chain, the monosaccharide is classified as an aldose. If the carbonyl group is within the chain, it is classified as a ketose.
4. Step 4: Eliminate the incorrect options based on the functional groups. Phosphate and methyl groups are not characteristic of all monosaccharides. Carboxyl and amino groups are found in amino acids, not monosaccharides. Sulfhydryl and ester groups are not relevant to monosaccharides either.
5. Step 5: Conclude that the correct functional groups present in all monosaccharides are hydroxyl (-OH) and carbonyl (C=O) groups, as these are essential for their chemical structure and classification.