Refer to the disaccharide below to answer the following question(s) CHO Ho ??? HOCH ??? CHOH 35) In the figure above, the monosaccharide on the bottom is a(n) A) aldopentose B) ketopentose C) aldohexose D) aldoheptose E) ketohexose 37) Hydrolysis of the disaccharide above gives the monosaccharides A) fructose and ribose B) fructose and galactose C) ribose and glucose D) ribose and galactose E) fructose and lactose Solution 35 . ans :- Option B . Ketopentose Explanation :- Monosaccharides on the bottom is a beta fructose unit . fructose has the molecular formula C 6 H 12 O 6 and contain a ketonic functional group at carbon number 2 and 6 carbons in the straight chain ( open structure) .in the above structure of Sucrose i.e C 12 H 22 O 11 ( disaccharide ), fructose which is present at the bottom exist in its cyclic structure which is known as Haworth structure of fructose . in haworth structure of fructose the five membered ring ( named as furanose) contains four carbon atoms and one oxygen atom . Given disaccharide is Sucrose , which is composed of glucose ( form pyranose ring which is six membered ring) and beta fructose ( form furanose ring which is five mrmbered ring ) . these units are held together by alpha,beta -glycosidic linkage between C1 of glucose unit and C2 of the fructose unit . sucrose on hydrolysis gives glucose and fructose in the presence of enzyme called invertase as: C 12 H 22 O 11 +        H 2 O ---------------------------> C 6 H 12 O 6 (glucose) + C 6 H 12 O 6 (fructose) .

1. Refer to the disaccharide below to answer the following question(s) CHO Ho ??? HOCH ???
CHOH 35) In the figure above, the monosaccharide on the bottom is a(n) A) aldopentose B)
ketopentose C) aldohexose D) aldoheptose E) ketohexose 37) Hydrolysis of the disaccharide
above gives the monosaccharides A) fructose and ribose B) fructose and galactose C) ribose and
glucose D) ribose and galactose E) fructose and lactose
Solution
35 . ans :- Option B . Ketopentose
Explanation :- Monosaccharides on the bottom is a beta fructose unit . fructose has the
molecular formula C 6 H 12 O 6 and contain a ketonic functional group at carbon number 2 and 6
carbons in the straight chain ( open structure) .in the above structure of Sucrose i.e C 12 H 22 O 11 (
disaccharide ), fructose which is present at the bottom exist in its cyclic structure which is known
as Haworth structure of fructose . in haworth structure of fructose the five membered ring (
named as furanose) contains four carbon atoms and one oxygen atom .
Given disaccharide is Sucrose , which is composed of glucose ( form pyranose ring which is six
membered ring) and beta fructose ( form furanose ring which is five mrmbered ring ) . these
units are held together by alpha,beta -glycosidic linkage between C1 of glucose unit and C2 of
the fructose unit .
sucrose on hydrolysis gives glucose and fructose in the presence of enzyme called invertase as:
C 12 H 22 O 11 +Â Â Â Â Â Â Â H 2 O ---------------------------> C 6 H 12 O 6 (glucose) + C 6 H 12 O
6 (fructose)