di saccharide of carbohydrates

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SOHEL - 11209040 ( L ) Siddiqul Islam- 11209041Naziur Rahman-11209025 Azizul Haque-11209031Iqbal Hossin-11209033 Sakawat Hossain-12209001Sariful Islam-11209032

DI-SACCHARIDE OF CARBOHYDRATES

Topic of the Presentation is …

CarbohydrateA carbohydrate is an organic compound that

consists only of carbon, hydrogen, and oxygen, usually with a hydrogen : oxygen

atom ratio of 2:1

CON…

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.

CON… 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.

MonosaccharidesMonosaccharides 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.“

Classification of monosaccharides

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).

DisaccharidesTwo 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

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.

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.

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.

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.

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.

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