Dab tsi yog qhov txawv ntawm L-Cysteine thiabL-cystine?
L-Cysteine yog ib qho ntawm ob qho proteinogenic amino acids uas muaj cov sulfur atom (lwm yam yog methionine). Nws suav hais tias yog ib qho tsis tseem ceeb amino acid vim nws yog tsim nyob rau hauv tib neeg lub cev. Cov tib neeg uas tsis muaj cysteine, txawm li cas los xij, yuav tsum tau kho nrog tshuaj ntxiv.
Cysteine muaj cov mis mos empirical C3H7O2NS thiab qhov hnyav molecular ntawm 121.16. Cystine yog tsim los ntawm ob cysteine molecules koom nrog ib tug disulfide daim ntawv cog lus. Nws muaj cov mis mos empirical C6H12O4N2S2 thiab qhov hnyav molecular ntawm 240.31.
L-cystine yog dawb crystalline hmoov. Tsis muaj ntxhiab thiab tsis qab. Me ntsis soluble nyob rau hauv dej, insoluble nyob rau hauv ethanol thiab lwm yam organic solvents, yooj yim soluble nyob rau hauv dilute mineral acid thiab lye. Yooj yim decomposed nyob rau hauv kub lye. Melting point 260-261 degree . Isoelectric point pH 4.6.
Cystine yog ruaj khov dua li cysteine, thiab nws koom nrog cov protein synthesis thiab ntau yam txheej txheem metabolic tom qab hloov mus ua cysteine hauv lub cev, thiab nws muaj lub luag haujlwm ntawm kev txhawb cov plaub hau kev loj hlob thiab tiv thaiv kev laus ntawm daim tawv nqaij.