the hormone adrenaline ( epinephrine ) is formed from which of the following amino acids ?

Options

A. Glycine
B. Tyrosine
C. Tryptophan
D. Alanine

Answer

To determine which amino acid is responsible for the formation of the hormone adrenaline (also known as epinephrine), we can analyze the options provided:

1. **Glycine**: This amino acid is primarily involved in the formation of heme, which is a component of hemoglobin. It does not play a role in the synthesis of adrenaline.

2. **Tyrosine**: This is an amino acid that is directly involved in the synthesis of adrenaline. Tyrosine is converted into L-DOPA, which is then converted into dopamine, and subsequently into norepinephrine, which is further converted into epinephrine (adrenaline). Therefore, tyrosine is the correct answer.

3. **Tryptophan**: This amino acid is primarily known for being a precursor to serotonin, a neurotransmitter, and does not contribute to the synthesis of adrenaline.

4. **Alanine**: This amino acid is involved in various metabolic processes but is not directly related to the synthesis of adrenaline.

Based on this analysis, the amino acid responsible for the formation of adrenaline (epinephrine) is **tyrosine**.

### Final Answer:
The hormone adrenaline (epinephrine) is formed from the amino acid **tyrosine**.