Question

1)Simplify how many reducing groups are in the molecule dissacharide?DRAW STRUCTURES

Reducing Sugars Draw the structural formula for a-D-glucosyl-(16)-D-mannosamine and circle the part of this structure that makes the compound a reducing sugar.

2) There are 2 lactose formations of anomeric. Although no anomeric forms of sucrose have been reported. Explain why and draw the 2 forms

Answer 1

Sucrose CHOH Нон сон iffe Ho Hot OH H - Glyosidte linkage P-D-Fructo furanos -D-Glucopyranose In disaccharide Sucrose, c-1 of 2-D-gluco- Pyranose is linked to c-2 of B-D - fructo- furanose by glycosidic linkage. The reducing ! group of glucose and fructose are involved in glycosidic bond formation, hence sucrose is non-reducing sugar Maltose - CH2OH CHOH HAH Hot ro TT est 2-D-Glucopuranose H OH L-D-Glucopyran oseto

Jo maltose of one 2-D-gluce pusanose is winked to 0-4 of another 3D-glucopy anase molecule by glycosidic linkage. Thus maltase. contains 14 & glycoside bond Maltose having tree aldehyde group can be produced at c-1 in second glucose molecule. - Lactose and sucrose are both disaccharides but lactose has anomeric form but not sucrose because of these needs to be a free anomeric carbon end or an anomeric carbon that is not involved in any bond. If the anomeric carbon is not involved in any kind of bond, it is free to equilibriate to its straight chain or 2 cyclic isomeric forms. nomenic glycosidic bond Mणेला ROHV CHOH + Ho H oH OHH but in lactose nose is having sucrose the cal of B-D-galactopyod- free aldehyde group. CH₂OH CH HOH Lactose Lactose have anomeric form