In nucleoside, nitrogen base is attached to pentose sugar at

Options

A. 1
B. 2
C. 3
D. 5

Answer

To answer the question regarding where the nitrogen base is attached to the pentose sugar in a nucleoside, we can follow these steps:

1. **Define Nucleoside**: A nucleoside is a molecular structure that consists of a nitrogenous base (which can be either purine or pyrimidine) and a pentose sugar (which can be ribose or deoxyribose).

2. **Identify the Pentose Sugar**: The pentose sugar in nucleosides can either be ribose (found in RNA) or deoxyribose (found in DNA). Both sugars have five carbon atoms.

3. **Locate the Carbon Atoms**: In the pentose sugar, the carbon atoms are numbered from 1' (one prime) to 5' (five prime). The numbering starts at the carbon atom that is attached to the nitrogenous base.

4. **Determine the Attachment Point**: The nitrogen base is specifically attached to the 1' carbon of the pentose sugar. This is the carbon that connects the sugar to the nitrogenous base.

5. **Conclude the Answer**: Therefore, in a nucleoside, the nitrogen base is attached to the pentose sugar at the 1' carbon.

**Final Answer**: The nitrogen base is attached to the pentose sugar at the 1' carbon.

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