ʻO L-Cysteine kekahi o nā waikawa amino maoli he 20 a, ma waho aʻe o ka methionine, ʻo ia wale nō ka mea i loaʻa i ka sulfur.He thiol-containing non-essential amino acid i oxidized e hana i ka Cystine.He amino acid i loko o ke kanaka, pili i ka cystine, he mea nui ka Cysteine no ka synthesis protein, detoxification, a me nā hana metabolic like ʻole.Loaʻa i ka beta-keratin, ka protein nui i nā kui, ka ʻili, a me ka lauoho, Cysteine mea nui i ka hana collagen, a me ka elasticity o ka ʻili a me ke ʻano.