Vhitamini A
Suma muchidimbu
Vhitamini A inosanganisira mavhitamini A1 naA2. Mavhitamini A1 naA2 akafanana muchimiro) Retinol inogona kugadzirwa kubva ku beta-carotene inobva mumiti. Pasi pe catalysis ye β-carotene-15, 15'-peroxide (biooxygenase) mumuviri, β-carotene inogona kushandurwa kuita mamorekuru maviri e retinaldehyde (ratinal), uye retinaldehyde mu reductase. Inoderedzwa kuita retinol pasi pesimba re. Nokudaro, beta-carotene inozivikanwawo se vitamin A.
Hunhu hwemakemikari
Vhitamini A ipfu yekristaro yero kana kuti kristalo, isinganyungudike mumvura neglycerine, uye inonyungudika mune zvakawanda zvinonyungudutsa zvakaita sealcohols, ethers, hydrocarbons uye halogenated hydrocarbons. Zita remakemikari remuviri wevhitamini A - retinol ndiro all-trance 3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexene-1)-2,4,6,8-nontetraene-1-ol, ine ma bond mana akabatana padivi payo.
Mabasa emuviri nemigumisiro
Vhitamini A ivhitamini inonyungudika mumafuta, uye basa rayo remuviri rinonyanya kuitwa ne retinoic acid. Carotene inzvimbo inokosha yevhitamini A. Vhitamini A inonyanya kushanda mu carotene i beta-carotene. Kuwanda kwevhitamini A muura hwemunhu kunosvika chikamu chimwe muzvitanhatu chevhitamini A. Vhitamini A inonyanya kuchengetwa muchiropa mumuviri, ichitora 90% kusvika 95% yehuwandu hwese, uye huwandu hushoma hunochengetwa mumafuta. Vhitamini A inoita basa rakakosha mukushanda kwemuviri wemunhu.
