Nucleoside involves the combination of

Options

A. Sugar + base + `H_3PO_4`
B. Sugar + base
C. Sugar + acid
D. Sugar + `H_3PO_4`

Answer

To answer the question "Nucleoside involves the combination of," we need to identify the components that make up a nucleoside.

### Step-by-Step Solution:

1. **Understanding Nucleosides**:
- A nucleoside is a molecular structure that consists of two main components: a sugar and a nitrogenous base.

2. **Identifying the Components**:
- The sugar can be either ribose or deoxyribose.
- **Ribose**: This is a five-carbon sugar that is part of RNA (ribonucleic acid).
- **Deoxyribose**: This is a five-carbon sugar that is part of DNA (deoxyribonucleic acid).
- The nitrogenous base can be classified into two types:
- **Purine Bases**: Adenine (A) and Guanine (G).
- **Pyrimidine Bases**: Cytosine (C), Thymine (T), and Uracil (U).

3. **Combining the Components**:
- A nucleoside is formed when a sugar (either ribose or deoxyribose) is bonded to a nitrogenous base (either a purine or a pyrimidine).
- Therefore, the combination that defines a nucleoside is:
- **Sugar + Nitrogenous Base**.

4. **Conclusion**:
- Thus, the answer to the question is that a nucleoside involves the combination of a sugar and a nitrogenous base.

### Final Answer:
A nucleoside involves the combination of a sugar and a nitrogenous base.

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