Amino acids are the building blocks of proteins

~ geneticspkubarr

pku AA picture

Retrieved from Voet, Voet & Pratt. Biochemistry. 5th ed. (Dr. Purcell’s lecture)

 

Individuals with PKU are missing the phenyalalanine hydroxylase enzyme. This enzyme is needed to break down phenylalanine (Phe=an essential AA).

Phe and Trp are essential, and must be obtained from diet. Tyr is synthesized from Phe.

 

Phenylalanine is converted to tyrosine by the phenylalanine hydroxylase (PAH) enzyme. The gene that provides instructions for making this enzyme is located on the q arm of chromosome 12. Phenylketonuria is inherited in an autosomal recessive pattern, illustrated in the inset. The offspring of parents who each carry one altered copy of the gene and are unaffected have a 25% chance of inheriting two altered copies of the gene and being affected, a 50% chance of inheriting one altered copy of the gene and being unaffected and a 25% chance of having two normal copies of the gene and being unaffected.

Credit: Meletios /Shutterstock.com

 

One thought on “Amino acids are the building blocks of proteins”

  1. -There are 20 common amino acids (aa) found in proteins in both prokaryotes and eukaryotes

    -This sets limits on what the genetic code must be able to specify – at least 20 unique “words”

    -AA’s are grouped into chemically similar categories

    **Phe is a nonpolar AA (aromatic AA)**

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