Which of the following contains nitrogen ?

Options

A. Fats
B. Proteins
C. Carbohydrates
D. Hydrocarbons

Answer

To determine which of the following contains nitrogen, we will analyze each option provided: fats, proteins, carbohydrates, and hydrocarbons.

### Step-by-Step Solution:

1. **Examine Fats:**
- Fats are composed of long hydrocarbon chains and are derived from carboxylic acids.
- The primary elements in fats are carbon (C), hydrogen (H), and oxygen (O).
- **Conclusion:** Fats do not contain nitrogen. (Incorrect option)

2. **Examine Proteins:**
- Proteins are polymers made up of amino acids.
- The structure of an amino acid includes a carboxyl group, an amino group, and a variable R chain.
- The amino group contains nitrogen (N), making nitrogen an integral part of proteins.
- **Conclusion:** Proteins contain nitrogen. (Correct option)

3. **Examine Carbohydrates:**
- Carbohydrates are macromolecules composed of carbon (C), hydrogen (H), and oxygen (O).
- Common examples include sugars and starches, which do not contain nitrogen.
- **Conclusion:** Carbohydrates do not contain nitrogen. (Incorrect option)

4. **Examine Hydrocarbons:**
- Hydrocarbons are organic molecules made up solely of carbon (C) and hydrogen (H).
- Examples include methane, ethane, and propane, which do not contain any nitrogen.
- **Conclusion:** Hydrocarbons do not contain nitrogen. (Incorrect option)

### Final Answer:
The only option that contains nitrogen is **Proteins**.

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