Chapter 18, Problem 11P

(a)

Summary Introduction

To suggest: The enzyme that might be deficient in the child and to propose a treatment.

Introduction:

The vomiting after the child is fed is related to the symptoms of disease called as phenylketonuria. The physical development and weight of the child are below normal. White patches present in the hair of child are also included in the symptoms of phenylketonuria disease.

(b)

Summary Introduction

To determine:  The reason for the presence of phenylalanine in urine in larger amounts.

Introduction:

The enzyme phenylalanine hydroxylase is necessary for the catabolism of amino acid phenylalanine. This amino acid is present in the tissues and blood in body. It is excreted through the urinary passage.

(c)

Summary Introduction

To determine:  The source of phenylpyruvate and phenyllactate. Also determine the reason that this pathway comes into play when the concentration of phenylalanine rises.

Introduction:

The metabolism of phenylalanine in the human body does not require the enzyme phenylalanine hydroxylase. The metabolism process takes place in the absence of phenylalanine hydroxylase enzyme.

(d)

Summary Introduction

To determine: The reason that boy’s hair contains patches of white color.

Introduction:

The white patches in the hair of boy are observed due to the absence of melanin pigment in that area. The melanin is the pigment which decides the color of the skin. It appears during phenylketonuria diseases.