Qhov sib txawv tseem ceeb ntawm cov piam thaj galactose thiab mannose yog cov piam thaj yog cov qauv rau cov pa roj carbon monoxide thiab galactose yog C4 epimer ntawm qabzib, qhov mannose yog C2 epimer ntawm qabzib.
Ib epimer yog ib qho organic compound uas tau piav qhia nrog rau isomerism ntawm cov organic tebchaw. Peb tuaj yeem txhais lub epimer ua ib qho isomer ntawm ib qho kev sib xyaw uas muaj cov pa roj carbon asymmetric. Piv txwv li, galactose thiab mannose yog epimers ntawm qabzib.
Glucose yog dab tsi?
Glucose yog cov organic compound uas muaj cov tshuaj formula C6H12O6. Nws yog ib qho yooj yim qab zib molecule. Peb tuaj yeem pom cov piam thaj ua cov monosaccharide molecule ntau tshaj ntawm cov carbohydrate compounds. Nws cov peev txheej yog cov nroj tsuag (qhov twg cov piam thaj tsim tawm) thiab algae, uas photosynthesis tuaj yeem tsim cov piam thaj los ntawm carbon dioxide thiab dej, siv lub zog los ntawm tshav ntuj. Tsis tas li ntawd, nyob rau hauv lub zog metabolism ntawm cov tsiaj, qabzib yog qhov tseem ceeb tshaj plaws ntawm lub zog. Daim ntawv muaj zog ntawm cov piam thaj no hu ua starch thiab amylopectin thaum khaws cia hauv cov nroj tsuag, thiab nws yog hu ua glycogen hauv cov tsiaj. Peb tuaj yeem rho cov piam thaj los ntawm nws qhov chaw, thiab nws kuj muaj nyob rau hauv cov khoom lag luam hauv khw. Cov tshuaj no zoo li cov hmoov dawb thiab qab zib heev.
Glucose molecule hu ua hexose vim nws muaj rau carbon atoms ib molecule. Hexose yog ib pawg ntawm pawg ntawm monosaccharide. Muaj ob hom isomeric ntawm cov piam thaj li D-glucose thiab L-glucose thiab D-isomer yog qhov ruaj khov tshaj plaws thiab muaj ntau hom isomeric. Nws tshwm sim dav hauv qhov xwm txheej. Peb tuaj yeem tau txais cov piam thaj los ntawm hydrolysis ntawm carbohydrates xws li mis nyuj qab zib los yog lactose, los ntawm sucrose uas tshwm sim hauv qab zib, los ntawm m altose, los ntawm cellulose los ntawm cov nroj tsuag, thiab lwm yam.
Daim duab 01: Cov qauv ntawm Glucose
Thaum xav txog cov qauv tshuaj ntawm cov piam thaj molecule, nws muaj tsib pawg hydroxyl (-OH). Cov pab pawg hydroxyl no tau teeb tsa hauv ib qho qauv raws nws cov pob txha rau-carbon. Sib nrug los ntawm muaj ob daim ntawv isomeric, muaj ob qhov sib txawv ntawm hydroxyl pawg hauv cov qauv ntawm cov suab thaj; cov no yog lub npe hu ua alpha qauv thiab beta qauv.
Galactose yog dab tsi?
Galactose yog C4 epimer ntawm cov piam thaj molecule. Yog li ntawd, galactose kuj muaj cov tshuaj tib yam li qabzib (C6H12O6). Qee lub sij hawm lub npe sib xyaw no yog luv ua Gal. Nws yog monosaccharide qab zib molecule muaj qab zib saj zoo ib yam li qabzib. Peb tuaj yeem muab lub npe no ua aldohexose vim tias nws yog hexose qab zib uas muaj aldehyde ua haujlwm pab pawg. Thaum lub galactose molecule ua ke nrog cov piam thaj molecule, nws tsim lactose molecule. Ntxiv mus, daim ntawv polymeric ntawm galactose yog galactan, thiab peb tuaj yeem pom hauv hemicellulose.
Thaum xav txog cov qauv tshuaj ntawm galactose, nws tuaj yeem tshwm sim hauv ob qho tib si qhib-chain thiab cyclic daim ntawv. Muaj ib pawg carbonyl ntawm qhov kawg ntawm cov saw hlau. Muaj plaub isomers ntawm galactose molecule uas muaj nyob rau hauv daim ntawv cyclic. Cov ntawv cyclic no muaj ob daim ntawv anomeric li alpha thiab beta forms.
Daim duab 02: Plaub Cyclic Daim Ntawv ntawm Galactose
Peb tuaj yeem pom cov peev txheej ntawm galactose feem ntau ntawm cov khoom siv mis nyuj xws li mis nyuj tshiab, yogurt, hauv avocados, qab zib beets, thiab lwm yam. Tsis tas li ntawd, galactose molecules tuaj yeem ua rau hauv peb lub cev.
Mannose yog dab tsi?
Mannose yog C2 epimer ntawm cov piam thaj molecule. Nws yog cov piam thaj molecule hauv aldohexose series ntawm carbohydrates. Cov tshuaj no tseem ceeb heev hauv tib neeg cov metabolism, xws li hauv glycosylation ntawm qee cov protein molecules.
Daim duab 03: Cov Qauv Tshuaj ntawm Mannose
Peb tuaj yeem pom mannose molecule tshwm sim nyob rau hauv ob daim ntawv raws li cov qauv pyranose nplhaib thiab cov qauv furanose nplhaib. Lub nplhaib pyranose muaj rau carbon atoms thaum lub nplhaib furanose muaj tsib carbon atoms hauv lub nplhaib. Txawm li cas los xij, txhua lub nplhaib kaw zoo li muaj alpha lossis beta configuration ntawm anomeric carbon centre.
Peb tuaj yeem tsim mannose los ntawm oxidation ntawm mannitol lossis los ntawm cov piam thaj los ntawm txoj kev hloov pauv ntawm Lory-de Bruyn-van Ekenstein. Ob txoj kev no tseem ceeb heev vim tias peb yuav tsum tsim cov mannose los ua cov khoom noj khoom haus uas tseem ceeb hauv kev tiv thaiv kab mob urinary.
Thaum xav txog cov qauv tshuaj ntawm mannose molecule, nws txawv ntawm cov qauv ntawm cov piam thaj ntawm qhov chaw thib ob carbon chiral (C2 txoj haujlwm). Lub mannose molecule qhia tau hais tias 4C1 pucker nyob rau hauv daim ntawv kua nplhaib. Qhov sib txawv ntawm cov piam thaj thiab mannose no ua rau muaj qhov sib txawv ntawm biochemical ntawm ob hexoses.
Qhov txawv ntawm Glucose Galactose thiab Mannose yog dab tsi?
Galactose thiab mannose yog epimers ntawm cov piam thaj molecule. Qhov sib txawv tseem ceeb ntawm cov piam thaj galactose thiab mannose yog cov piam thaj yog 6-carbon qauv thiab galactose yog C4 epimer ntawm qabzib thaum mannose yog C2 epimer ntawm qabzib. Tsis tas li ntawd, cov piam thaj yog tsim los ntawm photosynthesis hauv cov nroj tsuag. Galactose yog tsim los ntawm hydrolysis ntawm lactose uas yog catalyzed los ntawm lactase enzyme thaum mannose yog tsim los ntawm oxidation ntawm mannitol los yog los ntawm cov piam thaj los ntawm txoj kev hloov ntawm Lory-de Bruyn-van Ekenstein.
Hauv qab infographic tabulates qhov sib txawv ntawm qabzib galactose thiab mannose kom meej.
Summary – Glucose Galactose vs Mannose
Ib tus epimer yog ib qho isomer ntawm ib qho kev sib xyaw uas muaj cov pa roj carbon asymmetric. Galactose thiab mannose yog epimers ntawm qabzib. Qhov sib txawv tseem ceeb ntawm cov piam thaj galactose thiab mannose yog cov piam thaj yog 6-carbon qauv thiab galactose yog C4 epimer ntawm qabzib thaum mannose yog C2 epimer ntawm qabzib.
