In phenylketonuria, the amino acid (i) is not converted into (ii). Select the correct option to fill in the blanks (i) & (ii)

Options

A. (i) Ketone, (ii) Urea
B. (i) Phenylalanine, (ii) Urea
C. (i) Phenoxy acetic acid, (ii) Ketone
D. (i) Phenylalanine, (ii) Tyrosine

Answer

To solve the question regarding phenylketonuria, we need to identify the amino acids involved in this metabolic disorder. Here’s a step-by-step breakdown:

### Step 1: Understand Phenylketonuria (PKU)
Phenylketonuria is a genetic disorder that results from a deficiency in the enzyme phenylalanine hydroxylase (PAH). This enzyme is crucial for the metabolism of the amino acid phenylalanine.

**Hint:** PKU is related to a specific enzyme deficiency affecting amino acid metabolism.

### Step 2: Identify the Amino Acids
In normal metabolism, phenylalanine (the first amino acid) is converted into tyrosine (the second amino acid) through the action of the enzyme PAH.

**Hint:** Think about the normal metabolic pathway involving phenylalanine and tyrosine.

### Step 3: Determine the Impact of the Disorder
Due to the deficiency of the enzyme PAH in individuals with PKU, phenylalanine cannot be converted into tyrosine. This leads to an accumulation of phenylalanine and a deficiency of tyrosine.

**Hint:** Consider what happens when an enzyme is deficient in a metabolic pathway.

### Step 4: Fill in the Blanks
Based on the information gathered:
- (i) The amino acid that is not converted is **phenylalanine**.
- (ii) The amino acid it is supposed to be converted into is **tyrosine**.

Thus, the correct answer to fill in the blanks is:
(i) phenylalanine, (ii) tyrosine.

**Final Answer:** In phenylketonuria, the amino acid (i) is phenylalanine and is not converted into (ii) tyrosine.