I-maltose
I-Maltose (/ ˈmɔːltoʊs / noma / ˈmɔːltoʊz /), eyaziwa nangokuthi i-maltobiose noma ushukela we-malt, iyi-disaccharide eyenziwe ngamayunithi amabili kashukela ahlanganiswe ne-α (1 → 4) bond. Ku-isomaltose yesomerom, ama-molecule amabili eglucose ahlanganiswe ne-α (1 → 6) bond.IMaltose uyilungu lamayunithi amabili ochungechunge lwe-amylose homologous, okuyisisekelo sesakhiwo sesitashi. Lapho i-alpha-amylase iphula isitashi, isusa amayunithi amabili eglucose ngasikhathi sinye, ikhiqize i-maltose. [1] Isibonelo salokhu kusabela sitholakala embewini ehlumayo, yingakho yaqanjwa ngegama lemithombo. Ngokungafani ne-sucrose, ushukela owehlisayo.[1]
![isakhiwo ngamakhemikhali](http://178.128.105.246/content-http-upload.wikimedia.org/wikipedia/commons/thumb/7/7c/Maltose_struct.svg/522px-Maltose_struct.svg.png)
Umlando
[hlela | Hlela umthombo]IMaltose 'yatholwa' ngu-Augustin-Pierre Dubrunfaut, yize lokhu kutholwa kwakungamukelwa kabanzi kwaze kwaqinisekiswa ngo-1872 ngusokhemisi nophuza utshwala wase-Ireland uCornelius O'Sullivan. [2] [3]Igama layo livela emithombo, lihlanganiswe nesijobelelo u-'ose 'esisetshenziswa emagameni kashukela.
Izici
[hlela | Hlela umthombo]Njenge-glucose, i-maltose ushukela owehlisayo, ngoba indandatho yenye yezingxenye ezimbili zeshukela ingavuleka ukwethula iqembu lama-aldehyde lamahhala; enye ayikwazi ngenxa yemvelo yesibopho se-glycosidic. I-Maltose ingahle ihlehliswe ibe yi-glucose yi-maltase enzyme, ekhipha i-hydrolysis yesibopho se-glycosidic.
IMaltose esisombululo samanzi ikhombisa ukuguquguquka, ngoba ama-α nama-β isomers akhiwa ngokuhluka okuhlukile kwekhabhoni ye-anomeric anokushintshana okuhlukile, futhi ezixazululweni ezinamanzi, lawa mafomu amabili asesilinganisweni. I-Maltose ingatholakala kalula ngokuhlolwa kwe-Woehlk noma ukuhlolwa kuka-Fearon ku-methylamine.
Inokunambitheka okumnandi, kepha ingu-30-60% kuphela njengoshukela, kuya ngokuhlunga.Isixazululo se-maltose esingu-10% singama-35% njengoshukela njenge-sucrose.
Imithombo nokumuncwa
[hlela | Hlela umthombo]IMaltose yingxenye yemithombo, into etholakala ngenqubo yokuvumela okusanhlamvu ukuba kuthambe emanzini kuhlume. Iphinde ibe khona ngobuningi obuhlukahluka kakhulu emikhiqizweni yesitashi esakhiwe ngamanzi amancane njenge-maltodextrin, isiraphu yommbila kanye nesitashi esine-asidi.
Ebantwini i-maltose idilizwa ama-enzyme e-maltase ahlukahlukene, enikeza ama-molecule amabili eglucose angacutshungulwa ngokuqhubekayo: angahle ahlulwe ukuze anikeze amandla, noma agcinwe njenge-glycogen. Ukuntuleka kwe-enzyme ye-sucrase-isomaltase kubantu kubangela ukungabekezelelani kwe-sucrose, kepha ngoba kunezinhlayiya ezine ze-maltase ezihlukene, ukungabekezelelani ngokuphelele kwe-maltose akuvamile.
Isakhiwo nesiqeshana
[hlela | Hlela umthombo]Ama-carbohydrate ngokuvamile ahlukaniswa ngama-monosaccharides, ama-oligosaccharides, nama-polysaccharides ngokuya ngenani lama-subunits kashukela. IMaltose, enamayunithi amabili kashukela, iyi-disaccharide, ewela ngaphansi kwama-oligosaccharides. I-glucose yi-hexose: i-monosaccharide equkethe ama-athomu ayisithupha ekhabhoni. Amayunithi amabili eglucose asefomini ye-pyranose futhi ahlanganiswe yi-O-glycosidic bond, ne-carbon yokuqala (C1) yeglucose yokuqala exhunywe ne-carbon yesine (C4) yeshukela le-glucose yesibili, ekhonjiswe njenge (1 → 4) . Isixhumanisi saziwa njenge-α ngoba isibopho se-glycosidic kukhabhoni ye-anomeric (C1) sisendizeni ebhekene ne-CH
2OH osesikhundleni sendandatho efanayo (i-C6 yeglucose yokuqala). Uma isibopho se-glycosidic kukhabhoni ye-anomeric (C1) besendizeni efanayo ne-CH
2OH esikhundleni, izobekwa njengesibopho se-β (1 → 4), futhi i-molecule evelayo ingaba yi-cellobiose. I-anomeric carbon (C1) ye-molecule yesibili ye-glucose, engabandakanyeki kwisibopho se-glycosidic, ingaba yi-α- noma i-β-anomer ngokuya ngokuqondiswa kwesibopho seqembu le-hydroxyl elihlanganisiwe elihlobene ne-CH
2OH indawo yendandatho efanayo, okuholela ku-α-maltose noma i-β-maltose.
Isomer of maltose isomaltose. Lokhu kufana ne-maltose kepha esikhundleni sesibopho endaweni ye-α (1 → 4), kusendaweni ye-α (1 → 6), isibopho esifanayo esitholakala emaphoyiseni egatsha le-glycogen ne-amylopectin.
- ↑ Stoker, H. Stephen (2 January 2015). Organic and Biological Chemistry. Cengage Learning