Di-saccharide of carbohydrates

4. Topic of the Presentation is …

5. Carbohydrate
A carbohydrate is an organic compound that
consists only of carbon, hydrogen, and
oxygen, usually with a hydrogen : oxygen
atom ratio of 2:1

6.  Some exceptions exist; for example, deoxyribose, a component of
DNA, has the empirical formula C5H10O4. Carbohydrates are not
technically hydrates of carbon; structurally it is more accurate to
view them as polyhydroxy aldehydes and ketones.

7.  The carbohydrates (saccharides) are divided into four chemical groupings:
 Monosaccharides
 Disaccharides
 Oligosaccharides and
 Polysaccharides
 Monosaccharides and Disaccharides, which are smaller carbohydrates
(lower molecular weight).
 Carbohydrates perform numerous roles in living organisms.

8. Monosaccharides are the simplest carbohydrates in that they
cannot be hydrolyzed to smaller carbohydrates. They are
aldehydes or ketones with two or more hydroxyl groups. The
general chemical formula of an unmodified monosaccharide is
(C•H2O) n, literally a "carbon hydrate.“

9.  Monosaccharides are classified according to three different
characteristics:
 placement of its carbonyl group,
 number of carbon atoms it contains and
 its chiral handedness.
The α and β anomers of glucose. Note the position of the hydroxyl group (red or green) on the anomeric carbon
relative to the CH2OH group bound to carbon 5: they are either on the opposite sides (α), or the same side
(β).

10. Disaccharides
Two joined monosaccharides are called a disaccharide and these
are the simplest polysaccharides. Examples include sucrose
and lactose. They are composed of two monosaccharide units
bound together by a covalent bond known as a glycosidic
linkage. chemical formula, C12H22O11. These carbohydrates
have the general formula Cn(H2O)m

11. CON…
It is composed of one D-glucose molecule and one D-fructose molecule. The
systematic name for sucrose, O-α-D-glucopyranosyl-(1→2)-D-
fructofuranoside, indicates four things:
 Its monosaccharides: glucose and fructose
 Their ring types: glucose is a pyranose, and fructose is a furanose
 How they are linked together: the oxygen on carbon number 1 (C1) of α-D-
glucose is linked to the C2 of D-fructose.
 The -oside suffix indicates that the anomeric carbon of both
monosaccharides participates in the glycosidic bond.

12. Importance
Disaccharide such as sucrose and lactose serve as major source of
Energy. Cellulose(A polysaccharide) is the principal constituent
of plant cell walls. Glycogen(A Polysaccharide) is the
carbohydrate storage product of animals and some bacteria.
NUCLEIC ACIDS
 They carry chemical energy in their bonds.
 They are part of certain enzymes
 They serve as specific signaling molecules.

13. Importance in Sucrose
The disaccharide important for the nutrition is—as other sugars too—
not a rigid, but a flexible structure. Whether from sugar cane (20%
by weight) or sugar beets (15% by weight), and whether raw or
refined, common sugar is still sucrose.

14. Importance in Maltose
 The disaccharide obtained by enzyme-catalyzed hydrolysis
of starch, consists of two D-glucopyranoses joined by a 1,4'-
beta-glycoside bond. Both maltose and cellobiose are
reducing sugars because the anomeric carbons on the right-
hand sugar are part of a hemiacetal.

15. Importance in Lactose
Lactose is a disaccharide that occurs naturally in both human
and cow's milk. It is widely used in baking and in
commercial infant-milk formulas. Like cellobiose and
maltose, lactose is a reducing sugar. It exhibits muta-
rotation and is a 1,4'-beta-linked glycoside.