Vithamine A
Hlahisa ka bokhutšoanyane
Vithamine A e kenyelletsa divithamine A1 le A2. Divithamine A1 le A2 di tshwana ka sebopeho) Retinol e ka etswa ho tswa ho beta-carotene e tswang dimeleng. Tlas'a catalysis ya β-carotene-15, 15'-peroxide (biooxygenase) mmeleng, β-carotene e ka fetolwa ho ba dimolekhule tse pedi tsa retinaldehyde (ratinal), le retinaldehyde ho reductase. E fokotswa ho ba retinol tlasa tshusumetso ya. Ka hona, beta-carotene e boetse e tsejwa e le vithamine A.
Litšobotsi tsa lik'hemik'hale
Vithamine A ke kristale e mosehla e nang le matheba kapa phofo e kristale, e sa qhibiliheng metsing le glycerine, 'me e qhibiliha ka har'a metsoako e mengata ea lintho tse phelang tse kang alcohols, ethers, hydrocarbons le halogenated hydrocarbons. Lebitso la lik'hemik'hale la 'mele oa vithamine A - retinol ke all-trance 3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexene-1)-2,4,6,8-nontetraene-1-ol, e nang le maqhama a mabeli a kopaneng a mane ketane ea eona e ka thoko.
Mesebetsi le litlamorao tsa 'mele
Vithamine A ke vithamine e qhibilihang mafura, 'me mosebetsi oa eona oa 'mele o ka sehloohong ke oa retinoic acid. Carotene ke mohloli oa bohlokoa oa vithamine A. Vithamine A e sebetsang ka ho fetisisa ka har'a carotene ke beta-carotene. Sekhahla sa ho monngoa ha 'mele ka maleng a motho ke hoo e ka bang karolo ea botšelela ea vithamine A. Vithamine A e bolokoa haholo sebeteng 'meleng, e etsang hoo e ka bang 90% ho isa ho 95% ea kakaretso, 'me e nyane e bolokoa liseleng tsa mafura. Vithamine A e bapala karolo ea bohlokoa haholo mosebetsing oa metabolism oa 'mele oa motho.
