Biochemical reagents are widely used for detection of biomolecules. A reagent that specifically detects a carbonyl group (C=0) in a biomolecule will yield a positive test with

Options

A. protein
B. carbohydrate
C. Fats
D. all of these

Answer

To determine which biomolecule will yield a positive test with a reagent that specifically detects a carbonyl group (C=O), we can analyze the structures of proteins, carbohydrates, and fats.

### Step-by-Step Solution:

1. **Understanding Carbonyl Groups**: A carbonyl group is characterized by a carbon atom double-bonded to an oxygen atom (C=O). It is a functional group found in various biomolecules.

2. **Analyzing Proteins**: Proteins are made up of amino acids linked by peptide bonds. The structure of proteins includes an amino group (NH2), a carboxyl group (COOH), and a carbon chain. While proteins do contain carbonyl groups as part of their structure (in the peptide bonds), these groups are involved in bond formation and are not free to react with detection reagents.

3. **Analyzing Carbohydrates**: The simplest carbohydrates, such as monosaccharides, can have carbonyl groups (like in aldoses and ketoses). However, the question specifies a reagent that detects carbonyl groups, and many carbohydrates do not have free carbonyl groups in their stable forms. Therefore, they may not yield a positive test.

4. **Analyzing Fats**: Fats, or lipids, typically consist of long hydrocarbon chains and may contain functional groups like carboxyl groups (COOH). The carboxyl group contains a carbonyl group (C=O) that is free and can be detected by biochemical reagents.

5. **Conclusion**: Among proteins, carbohydrates, and fats, the reagent that detects a carbonyl group will yield a positive test with fats due to the presence of free carbonyl groups in the carboxylic acid functional groups.

### Final Answer:
The reagent that specifically detects a carbonyl group (C=O) will yield a positive test with **fats**.

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