A person with PKU is unable to break down which of the following?
Group of answer choices
A. DNA
B. An amino acid
C. A sugar
D. Lipids
The correct answer and explanation is:
The correct answer is B. An amino acid.
Phenylketonuria (PKU) is a genetic disorder that affects the metabolism of the amino acid phenylalanine. Normally, phenylalanine is converted into another amino acid, tyrosine, by the enzyme phenylalanine hydroxylase. In individuals with PKU, this enzyme is either deficient or absent, preventing the breakdown of phenylalanine. As a result, phenylalanine builds up in the body, which can lead to severe neurological problems such as intellectual disability, developmental delays, and behavioral issues if not managed properly.
Since phenylalanine is an essential amino acid, it is present in many foods, particularly in protein-rich items like meat, dairy, and certain grains. When a person with PKU consumes foods containing phenylalanine, the excess amino acid accumulates in the blood and brain. This accumulation can be toxic, affecting brain development, especially in infants and young children.
The treatment for PKU typically involves a strict, lifelong diet that limits the intake of phenylalanine. This diet is often supplemented with a special formula that provides essential nutrients without phenylalanine. Newborns are screened for PKU shortly after birth to catch the disorder early, allowing for immediate dietary intervention to prevent damage.
If left untreated, PKU can cause irreversible cognitive damage. However, with early detection and dietary management, individuals with PKU can lead healthy lives, avoiding the severe consequences associated with this metabolic disorder.