A nucleotide connected with coenzyme formation is

Options

A. Nicotinamide
B. Purine
C. Pyrimidine
D. None of the above

Answer

To solve the question "A nucleotide connected with coenzyme formation is," we will analyze the options provided: nicotinamide, purine, pyrimidine, and none of the above.

### Step-by-Step Solution:

1. **Understanding Nucleotides and Coenzymes**:
- Nucleotides are the building blocks of nucleic acids (DNA and RNA) and consist of a nitrogenous base, a sugar, and a phosphate group.
- Coenzymes are organic molecules that assist enzymes in catalyzing reactions. Many coenzymes are derived from vitamins and are often nucleotides or contain nucleotide components.

2. **Analyzing the Options**:
- **Nicotinamide**: This is a form of vitamin B3 and is part of the coenzyme NAD (Nicotinamide Adenine Dinucleotide). NAD plays a crucial role in metabolism as it acts as an electron carrier in cellular respiration.
- **Purine**: This is a category of nitrogenous bases that includes adenine and guanine. Purines themselves are not nucleotides; they are components of nucleotides.
- **Pyrimidine**: Similar to purines, pyrimidines (such as cytosine, thymine, and uracil) are also nitrogenous bases and not nucleotides.
- **None of the Above**: This option suggests that none of the provided options are correct.

3. **Identifying the Correct Answer**:
- Since nicotinamide is part of the structure of NAD, which is a coenzyme, it is the correct answer. Purines and pyrimidines do not directly connect with coenzyme formation as they are merely bases that form nucleotides.

4. **Conclusion**:
- The correct answer to the question is **nicotinamide**.

### Final Answer:
The nucleotide connected with coenzyme formation is **nicotinamide**.