Phosphorus is a constituent of:

Options

A. fat
B. proteins
C. Nucleotides
D. carbohydrates

Answer

To determine which of the given options phosphorus is a constituent of, let's analyze each option step by step.

### Step 1: Analyze the first option - Fat
- Fats are composed of glycerol and fatty acids.
- Glycerol has three hydroxyl (OH) groups, and fatty acids consist of long hydrocarbon chains with a carboxyl group.
- Phosphorus is not a component of fats.

**Conclusion:** Phosphorus is not a constituent of fat.

### Step 2: Analyze the second option - Protein
- Proteins are made up of amino acids.
- Amino acids contain an amino group (NH2) and a carboxyl group (COOH).
- Phosphorus is not a part of the basic structure of amino acids.

**Conclusion:** Phosphorus is not a constituent of proteins.

### Step 3: Analyze the third option - Nucleotide
- Nucleotides are the building blocks of nucleic acids (DNA and RNA).
- A nucleotide consists of a pentose sugar (deoxyribose in DNA, ribose in RNA), a nitrogenous base (adenine, guanine, cytosine, thymine, or uracil), and a phosphate group.
- The presence of the phosphate group indicates that phosphorus is indeed a component of nucleotides.

**Conclusion:** Phosphorus is a constituent of nucleotides.

### Step 4: Analyze the fourth option - Carbohydrates
- Carbohydrates are primarily composed of sugar molecules and are classified as polysaccharides.
- They consist of long chains of sugar units (monosaccharides) and do not contain phosphorus.

**Conclusion:** Phosphorus is not a constituent of carbohydrates.

### Final Answer:
Phosphorus is a constituent of **nucleotides**.

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