Which of the following amino acids is present in ornithine cycle?

Options

A. Valine and cystine
B. Arginine and citrulline
C. Glycine and methionine
D. None of these

Answer

To determine which amino acids are present in the Ornithine cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Ornithine Cycle**: The Ornithine cycle, also known as the urea cycle, occurs primarily in the liver. It is a metabolic pathway that converts ammonia, which is toxic at high levels, into urea, which can be safely excreted from the body.

2. **Identify Key Components**: In the Ornithine cycle, several amino acids play crucial roles. The cycle involves the conversion of ammonia into urea, and certain amino acids are involved in this process.

3. **List Amino Acids in the Cycle**: The main amino acids involved in the Ornithine cycle are:
- **Ornithine**: This is a key amino acid that is regenerated in the cycle.
- **Citrulline**: This is produced from ornithine and is part of the cycle.
- **Arginine**: This amino acid is also produced in the cycle and can be further converted back to ornithine.

4. **Conclusion**: Based on the information, the amino acids that are present in the Ornithine cycle include **Arginine** and **Citrulline**.

5. **Select the Correct Answer**: Therefore, if the options provided include Arginine and Citrulline, that would be the correct choice.

### Final Answer:
The amino acids present in the Ornithine cycle are **Arginine and Citrulline**.

---