Which of the following is involved in the synthesis of the plant hormone IAA and the vasoconstriction serotonin ?

Options

A. Tryptophan
B. Tyrosine
C. Phenylalamine
D. None of these

Answer

To solve the question regarding which compound is involved in the synthesis of the plant hormone IAA (indole-3-acetic acid) and the vasoconstrictor serotonin, we can follow these steps:

### Step 1: Identify the Compounds
The question provides us with four options: tryptophan, tyrosine, phenylalanine, and none of these. We need to determine which of these is involved in the synthesis of both IAA and serotonin.

### Step 2: Understand the Role of Tryptophan
Tryptophan is an essential amino acid that serves as a precursor for several important biomolecules. It is known to be involved in the synthesis of serotonin, a neurotransmitter that plays a role in vasoconstriction.

### Step 3: Link Tryptophan to IAA
Tryptophan is also a precursor for indole-3-acetic acid (IAA), which is a major plant hormone involved in growth and development. Research has shown that tryptophan can be converted into IAA through various biochemical pathways.

### Step 4: Conclude the Answer
Since tryptophan is involved in the synthesis of both serotonin and IAA, we conclude that the correct answer to the question is **tryptophan**.

### Final Answer
The correct option is **tryptophan**.

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