How to Use cysteine in a Sentence

cysteine

noun
  • That amino acid is supposed to be cysteine, and has been in all humans examined to this point.
    — Mark Johnson and Kathleen Gallagher, Milwaukee Journal Sentinel, 21 Dec. 2010
  • Each video is great, but her reaction to tasting cysteine is memorable.
    — Brittany Trang, STAT, 4 Feb. 2026
  • Your body naturally contains more glycine and glutamine, but cysteine can be in short supply.
    — Good Housekeeping, 10 Feb. 2023
  • The body naturally produces taurine from the amino acid cysteine.
    — Jillian Kubala, Rd, Health, 5 Nov. 2024
  • Brassicas Brassicas, which is a type of broccoli, floods the body with cysteine.
    — Brian Patrick, Discover Magazine, 21 July 2021
  • The humble orbs contain the amino acid cysteine, which helps break down acetaldehyde, which is thought to be one of the causes of hangovers.
    — Emily Heil, Washington Post, 30 Dec. 2019
  • The cysteine in eggs, bacon, and even broccoli might help with the absorption of acetaldehyde, and the nausea.
    — Kyle Beechey, Bon Appétit, 25 Oct. 2019
  • Eggs are an awesome source of cysteine, which helps break down a headache-causing toxin that's produced when your body digests alcohol.
    — Elizabeth Narins, Cosmopolitan, 28 June 2017
  • Passion fruit, for example, is low in methionine and cysteine.
    — Deirdre Bardolf, FOXNews.com, 10 Aug. 2025
  • The synthetic form of the amino acid cysteine, NAC has some promising health benefits.
    — Good Housekeeping, 3 Aug. 2023
  • In the new study, the researchers combined cysteine with chemical relatives of fatty acids containing eight carbons apiece.
    — Bymitch Leslie, science.org, 30 Oct. 2024
  • Your liver relies on amino acids from protein — like glycine, cysteine and glutamate — to make glutathione, your body’s master antioxidant.
    — Lauren Mallers, Sacbee.com, 8 Oct. 2025
  • Both taurine and cysteine naturally occur in the body, while methionine can be consumed by eating protein sources.
    — Angelica Bottaro, Verywell Health, 30 Jan. 2025
  • The team noticed that, in particular, the free radicals reacted with cysteine, an amino acid used in protein production.
    — Christian Thorsberg, Smithsonian Magazine, 18 Jan. 2024
  • That being said, the researchers point out that eliminating cysteine from human diets is all but impossible because the amino acid is found in nearly all foods.
    — Michael Franco may 21, New Atlas, 21 May 2025
  • The subjects were then asked to swallow placebo or L-cysteine tablets containing vitamin supplements.
    — BostonGlobe.com, 19 Aug. 2020
  • Free radicals in tardigrades react with a protein called cysteine, the team discovered, but when those reactions are blocked, tardigrades can’t enter tun.
    — Carlyn Kranking, Smithsonian Magazine, 31 Dec. 2024
  • Under stressful conditions, with cysteine unavailable to the free radicals being produced, the tardigrades couldn’t form tuns.
    — Meghan Bartels, Scientific American, 17 Jan. 2024
  • In the search for another path to the fountain of youth, researchers have been exploring the role of methionine and cysteine, two of the body's nine essential amino acids which contain sulfur.
    — Sandee Lamotte, CNN, 3 Feb. 2020
  • Male zebra finches in the treatment group were fed dietary cysteine for a month along with the drug, ML349, that blocks pheomelanin synthesis.
    — Grrlscientist, Forbes.com, 16 Jan. 2026
  • The survival mechanism kicks off when cysteines, one of the amino acids that forms proteins in the body, come into contact with these oxygen free radicals and becomes oxidized, the researchers found.
    — Jenna Schnuer, CNN, 5 Feb. 2024
  • Glutathione is also linked to the newly popular NAC, or N-acetyl cysteine supplements.
    — Perri O. Blumberg, Men's Health, 25 Apr. 2023
  • Whey protein also contains high amounts of leucine, the most important amino acid in muscle growth, and cysteine, which aids in muscular development and metabolism.
    — Amber Smith, Discover Magazine, 16 Dec. 2022
  • The researchers received funding from Catapult Cat Oy, which sells the L-cysteine supplements.
    — Andrew Stuttaford, National Review, 20 Aug. 2020
  • This lack of orange plumage also implies that females lack the ability to neutralize cell damage due to the excessive accumulation of cysteine.
    — Grrlscientist, Forbes.com, 16 Jan. 2026
  • Plants use sulfur to manufacture cysteine and methionine, two amino acids important for producing protein.
    — Patrick Di Justo, WIRED, 28 July 2010
  • The new treatment is an inexpensive, over-the-counter supplement called N-acetyl cysteine, or NAC, that is widely available.
    — Cezary Podkul, WSJ, 28 Dec. 2020
  • The technology attaches fragments of potential small molecule drugs to another molecule that binds to cysteine, one of the amino acids that are the building blocks of proteins.
    — Bradley J. Fikes, sandiegouniontribune.com, 16 Oct. 2017
  • So the scientists exposed the tardigrades to different kinds of molecules known to block cysteine oxidation, as scientists call binding by a free radical.
    — Meghan Bartels, Scientific American, 17 Jan. 2024
  • While spice allergies are rare, a certain enzyme found in ginger (cysteine proteinase GP-1) may trigger allergic reactions in some people.
    — Lauren O'Connor, Ms, Health, 16 Sep. 2024

Some of these examples are programmatically compiled from various online sources to illustrate current usage of the word 'cysteine.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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