phenylalanine
noun
phe·nyl·al·a·nine
ˌfe-nᵊl-ˈa-lə-ˌnēn 
ˌfē-
: an essential amino acid C9H11NO2 that is converted in the normal body to tyrosine
Examples of phenylalanine in a Sentence
Recent Examples on the Web
Tuna contains phenylalanine and tryptophan, both of which have been linked to antidepressant properties.
—
Lindsey Desoto, Rd, Health, 9 Sep. 2024
This causes phenylalanine to build up in the blood, leading to brain damage and intellectual disability.34
Tyrosine is made from phenylalanine, so people with PKU typically have low levels of tyrosine in their blood.
—Lindsey Desoto, Rd, Ld, Health, 10 Aug. 2024
People with a rare genetic disorder called phenylketonuria (PKU) disease, a difficulty metabolizing phenylalanine, should avoid or restrict aspartame.
—Anna Giorgi, Verywell Health, 8 Aug. 2024
Because aspartame contains the natural amino acid phenylalanine, people with phenylketonuria should avoid aspartame.
—Trang Tran, Pharmd, Verywell Health, 26 July 2024
See all Example Sentences for phenylalanine 
These examples are automatically compiled from online sources to
illustrate current usage. Opinions expressed in the examples do not represent those of
Merriam-Webster or its editors.
Send us feedback
about these examples.
Lindsey Desoto, Rd, Health, 9 Sep. 2024
This causes phenylalanine to build up in the blood, leading to brain damage and intellectual disability.34
Tyrosine is made from phenylalanine, so people with PKU typically have low levels of tyrosine in their blood.
—Lindsey Desoto, Rd, Ld, Health, 10 Aug. 2024
People with a rare genetic disorder called phenylketonuria (PKU) disease, a difficulty metabolizing phenylalanine, should avoid or restrict aspartame.
—Anna Giorgi, Verywell Health, 8 Aug. 2024
Because aspartame contains the natural amino acid phenylalanine, people with phenylketonuria should avoid aspartame.
—Trang Tran, Pharmd, Verywell Health, 26 July 2024
See all Example Sentences for phenylalanine
Dictionary Entries Near phenylalanine
Cite this Entry
“Phenylalanine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/phenylalanine. Accessed 15 Nov. 2024.
Copy CitationMedical Definition
phenylalanine
noun
phe·nyl·al·a·nine
ˌfen-ᵊl-ˈal-ə-ˌnēn, ˌfēn-
: an essential amino acid C9H11NO2 that is obtained in its levorotatory L-form by the hydrolysis of proteins (as lactalbumin), that is essential in human nutrition, and that is converted in the normal body to tyrosine
—abbreviation Phe
see phenylketonuria, phenylpyruvic acid
Love words? Need even more definitions?
Merriam-Webster unabridged
Share