Qhov sib txawv tseem ceeb ntawm polyhydroxy aldehydes thiab polyhydroxy ketone yog tias polyhydroxy aldehydes muaj ib pawg aldehyde nrog ntau pawg -OH whereas polyhydroxy ketones muaj pawg ketone nrog ntau pawg -OH.
Cov ntsiab lus polyhydroxy aldehydes thiab polyhydroxy ketones piav qhia txog cov qauv ntawm carbohydrates. Ob lub tebchaw no muaj ntau pawg hydroxyl (-OH pawg) thiab pawg carbonyl (xws li aldehydes lossis ketone pawg).
YPolyhydroxy Aldehydes yog dab tsi?
Polyhydroxy aldehydes yog cov organic tebchaw uas muaj ntau pawg hydroxyl (-OH) thiab ib pawg aldehyde (-C(=O)H). Ntawm no, pawg carbonyl tshwm sim ntawm lub davhlau ya nyob twg carbon atom. Peb hu lawv "aldoses". Tsis tas li ntawd, cov pa roj carbon atom ntawm pawg aldehyde no tuaj yeem ua ke nrog ib qho ntawm pawg hydroxyl (thaum cov khoom sib xyaw ua ke hauv cov kua dej) los ua ib qho kev sib txuas uas peb hu ua "hemiacetal".
Daim duab 01: Txawv Aldoses
Monosaccharides yog cov piv txwv zoo ntawm polyhydroxy aldehydes. Cov no yog cov suab thaj yooj yim thiab lawv ua raws li lub tsev blocks ntawm carbohydrates xws li disaccharides thiab polysaccharides.
YPolyhydroxy Ketones yog dab tsi?
Polyhydroxy ketones yog cov organic tebchaw uas muaj ntau pawg hydroxyl thiab pawg ketone (-C(=O)-). Ntawm no, pawg carbonyl tshwm sim ntawm qhov thib ob carbon atom los ntawm lub davhlau ya nyob twg ntawm cov molecule. Peb hu cov tebchaw no "ketoses". Ib yam li aldoses, cov tebchaw no kuj tuaj yeem ua ke nrog ib pawg hydroxyl ntawm tib lub molecule (tshem tawm cov dej molecule) los tsim ib lub voj voog, uas yog hemiketal.
Qee cov monosaccharides tshwm sim ua ketoses. Qhov yooj yim ketose yog dihydroxyacetone. Ntxiv mus, nws muaj peb carbon atoms, thiab pawg carbonyl yog nyob rau ntawm ob / nruab nrab carbon atom. Tag nrho cov ketose monosaccharides txo cov suab thaj.
Daim duab 02: Txawv Ketoses
Peb tuaj yeem sib txawv ntawm aldoses thiab ketoses los ntawm Seliwanoff qhov kev sim uas peb ua kom sov cov qauv ntawm monosaccharides nyob rau hauv muaj cov kua qaub thiab resorcinol. Lub hauv paus ntawm qhov kev sim no yog lub cev qhuav dej ntawm cov molecules. Lub cev qhuav dej tshwm sim sai sai hauv ketoses thiab hauv aldoses nws tshwm sim qeeb heev. Ntawm no, ketoses muab xim liab tsaus thaum aldoses muab xim liab ntawm cov tshuaj tiv thaiv sib xyaw.
Qhov txawv ntawm Polyhydroxy Aldehydes thiab Polyhydroxy Ketone yog dab tsi?
Polyhydroxy aldehydes yog cov organic tebchaw uas muaj ntau pawg hydroxyl (-OH) thiab pawg aldehyde (-C(=O)H) thaum Polyhydroxy ketones yog cov organic tebchaw uas muaj ntau pawg hydroxyl thiab pawg ketone (-C(=O)-). Yog li, qhov sib txawv tseem ceeb ntawm polyhydroxy aldehydes thiab polyhydroxy ketone yog lawv pab pawg ua haujlwm: aldehyde pawg lossis ketone pawg.
Txawm li cas los xij, ob lub tebchaw no muaj pawg carbonyl. Tab sis, nyob rau hauv polyhydroxy aldehydes, pawg carbonyl tshwm sim ntawm lub davhlau ya nyob twg ntawm lub molecule thaum, nyob rau hauv polyhydroxy ketones, nws tshwm sim nyob rau hauv lub thib ob carbon atom ntawm ib tug davhlau ya nyob twg. Yog li, qhov no kuj yog qhov sib txawv ntawm polyhydroxy aldehydes thiab polyhydroxy ketone. Tsis tas li ntawd, ob lub tebchaw no tuaj yeem tsim cov kab sib txuas ntawm kev sib txuas ua haujlwm nrog ib pawg ntawm hydroxyl, tshem tawm cov dej molecule. Ntawm no, lub cyclic compound uas tsim los ntawm polyhydroxy aldehyde yog "hemiacetal" thaum rau polyhydroxy ketones nws yog "hemiketal".
Hauv qab no yog cov ntsiab lus ntawm qhov sib txawv ntawm polyhydroxy aldehydes thiab polyhydroxy ketone.
Summary – Polyhydroxy Aldehydes vs Polyhydroxy Ketone
Hauv cov ntsiab lus, polyhydroxy aldehydes yog cov organic tebchaw uas muaj ntau pawg hydroxyl (-OH) thiab pawg aldehyde (-C(=O)H) thaum Polyhydroxy ketones yog cov organic tebchaw uas muaj ntau pawg hydroxyl thiab pawg ketone (- C(=O)-). Yog li, qhov sib txawv tseem ceeb ntawm polyhydroxy aldehydes thiab polyhydroxy ketone yog pawg ua haujlwm: aldehyde pawg lossis ketone pawg. Txawm li cas los xij, ob lub tebchaw no muaj pawg carbonyl. Hauv polyhydroxy aldehydes, pawg carbonyl tshwm sim ntawm lub davhlau ya nyob twg ntawm lub molecule whereas nyob rau hauv polyhydroxy ketones nws tshwm sim nyob rau hauv lub thib ob carbon atom ntawm ib lub davhlau ya nyob twg.
