Prepare for NCLEX success with today’s question: Learn how phenylalanine is acquired in a pediatric client with phenylketonuria (PKU). Can you identify the correct mechanism?
The nurse in the primary care office is educating the caregivers of a pediatric client with phenylketonuria (PKU). By which mechanism is phenylalanine acquired?
A. Through the conversion of tyrosine
B. Through the consumption of proteins
C. Through ingestion of carbohydrates
D. Through metabolism by the sympathetic nervous system
Scroll down for the correct answer!
The correct answer to today’s NCLEX-RN® Question is…
B. Through the consumption of proteins
Rationale: Phenylalanine is an essential amino acid, meaning that it must be acquired through the consumption of protein. The body cannot make or store phenylalanine, so excess may be converted into another compound.
Major Takeaway
Amino acids are the basic building blocks that make up proteins. Phenylalanine is one of the essential amino acids, meaning the human body cannot make it, so it must be acquired through protein in the diet. Since the body cannot store amino acids, any excess amino acids are converted into glucose or ketones to be used for energy. Normally, phenylalanine is converted into the amino acid tyrosine by the enzyme phenylalanine hydroxylase with the help of a cofactor called tetrahydrobiopterin (BH4). Tyrosine is then made into several other products, including dopamine and serotonin, which are neurotransmitters that neurons use to communicate, as well as norepinephrine and epinephrine, which are also neurotransmitters and hormones used by the sympathetic nervous system.
Incorrect answer explanations
A. Through the conversion of tyrosine
Rationale: Tyrosine is an amino acid; although phenylalanine can be converted into tyrosine, it is not acquired through the transformation of tyrosine.
C. Through ingestion of carbohydrates
Rationale: Phenylalanine is not acquired through this mechanism as carbohydrates do not contain phenylalanine.
D. Through metabolism by the sympathetic nervous system
Rationale: The sympathetic nervous system utilizes neurotransmitters, which can be made from phenylalanine. However, the production of phenylalanine does not involve the sympathetic nervous system.
Want more NCLEX®-style practice questions? Try Osmosis by Elsevier today! Access your free trial and discover why millions of current and future clinicians and caregivers love learning with us.
Leave a Reply