The amino acid trytophan is the precursor for the synthesis of

Options

A. Thyroxine and Triiodothyronine
B. Estrogen and Progesterone
C. Cortisol and Cortisone
D. Melatonin and Serotonin

Answer

**Step-by-Step Solution:**

1. **Identify Tryptophan**: Tryptophan is an essential amino acid that plays a crucial role in the body. It is not synthesized by the body and must be obtained through diet.

2. **Function of Tryptophan**: Tryptophan is known for its role in the synthesis of important neurotransmitters and hormones. It is particularly known for being a precursor to serotonin.

3. **Synthesis of Serotonin**: When tryptophan is metabolized, it is converted into serotonin, which is a neurotransmitter that regulates mood, sleep, and appetite.

4. **Synthesis of Melatonin**: Serotonin can further be converted into melatonin, a hormone that regulates sleep-wake cycles and is produced by the pineal gland.

5. **Evaluate Options**: The question provides several options:
- Thyroxine and Triiodothyronine (derived from proteins)
- Estrogen and Progesterone (steroid hormones)
- Cortisol and Cortisone (steroid hormones)
- Melatonin and Serotonin (derived from tryptophan)

6. **Select the Correct Answer**: Since tryptophan is directly involved in the synthesis of serotonin and subsequently melatonin, the correct answer is **melatonin and serotonin**.

**Final Answer**: The amino acid tryptophan is the precursor for the synthesis of **melatonin and serotonin**.

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