Uric acid is produced by metabolism of

Options

A. Adenine
B. Guanine
C. Cytosine
D. Both 1 & 2

Answer

**Step-by-Step Solution:**

1. **Understanding Uric Acid Production**: Uric acid is a nitrogenous waste product formed during the breakdown of purines, which are a type of nucleotide.

2. **Identifying Purines**: The two main purines involved in this process are adenine and guanine. These compounds are essential components of nucleic acids (DNA and RNA).

3. **Metabolism of Guanine**:
- Guanine is first converted into xanthine through the action of the enzyme guanine deaminase.
- Xanthine is then further oxidized to uric acid by the enzyme xanthine oxidase.

4. **Metabolism of Adenine**:
- Adenine is converted into inosine by the enzyme adenosine deaminase.
- Inosine is then converted into hypoxanthine.
- Hypoxanthine is subsequently converted into xanthine, again by the action of xanthine oxidase.
- Finally, xanthine is converted into uric acid by xanthine oxidase.

5. **Cytosine Metabolism**: Cytosine is a pyrimidine and does not contribute to uric acid production. Therefore, it is not involved in the metabolic pathway leading to uric acid.

6. **Conclusion**: Uric acid is produced by the metabolism of adenine and guanine, making the correct answer "both adenine and guanine."

**Final Answer**: Uric acid is produced by the metabolism of adenine and guanine.

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