Which one is nucleotide ?

Options

A. Uridylic acid
B. Thymidine
C. Cytosine
D. Glutamic acid.

Answer

To determine which option is a nucleotide, we need to understand the definitions and components of nucleotides, nucleosides, and nitrogenous bases.

### Step-by-Step Solution:

1. **Understanding Nucleotides**:
- A nucleotide is composed of three components: a nitrogenous base, a sugar molecule (ribose or deoxyribose), and one or more phosphate groups.

2. **Identifying Nitrogenous Bases**:
- There are five nitrogenous bases:
- Purines: Adenine (A), Guanine (G)
- Pyrimidines: Cytosine (C), Thymine (T), Uracil (U)

3. **Identifying Nucleosides**:
- A nucleoside consists of a nitrogenous base plus a sugar.
- Examples include:
- Adenine + sugar = Adenosine
- Guanine + sugar = Guanosine
- Thymine + sugar = Thymidine
- Cytosine + sugar = Cytidine
- Uracil + sugar = Uridine

4. **Identifying Nucleotides**:
- A nucleotide is a nucleoside with one or more phosphate groups attached.
- Examples include:
- Adenosine + phosphate = Adenylic acid (AMP)
- Guanosine + phosphate = Guanylic acid (GMP)
- Thymidine + phosphate = Thymidylic acid (TMP)
- Cytidine + phosphate = Cytidylic acid (CMP)
- Uridine + phosphate = Uridylic acid (UMP)

5. **Analyzing the Options**:
- **Ureteric acid**: Not a nucleotide.
- **Thymidine**: A nucleoside (not a nucleotide).
- **Cytosine**: A nitrogenous base (not a nucleotide).
- **Glutamic acid**: An amino acid (not a nucleotide).

6. **Conclusion**:
- The only option that can be identified as a nucleotide is **uridilic acid**, which is the nucleotide derived from uracil.

### Final Answer:
**Uridilic acid** is the nucleotide.