IDENTIFICATION OF CARBOHYDRATES

BILINGUAL BIOLOGY EDUCATION 2013

CARBOHYDRATES

• Compound groups that contain of C, H, and O element.

• Carbohyrates compound like to do reduction because contain of carbonyl group (-CO-) in shaped of aldehydes (R-CHO) or ketones (R-CO-R’), and also contain of so many hydroxyl groups (-OH)

Monosaccharides (Simple Sugars) Contain of 3-9 carbon element. Based on number

of carbons (3, 4, 5, 6), a monosaccharide is a triose, tetrose, pentose or hexose, etc.

TYPES OF CARBOHYDRATES

MonosaccharidesAldoses (e.g., glucose, galactose, Ribose & Deoxiribose) have an aldehyde group at one end.

Ketoses (e.g., fructose) have a keto group, usually at C2.

C

C OHH

C HHO

C OHH

C OHH

CH2OH

D-glucose

OH

C HHO

C OHH

C OHH

CH2OH

CH2OH

C O

D-fructose

Oligosaccharides

• a few monosaccharides covalently linked. • Disaccharides is 2 monosaccharides that

covalently linked usually called glycosides bond. Eg : maltose, sucrose and lactose

• The sweet taste of monosaccharides and oligo saccharides because of the relatively small mass

Polysaccharides

• Polymers consisting of chains of monosaccharide or disaccharide units.

• Polysaccharides usually white, not-crystalized, not sweet and unreductive.

• Eg : starch, amilum, gycogen, chitin, cellulose, etc

CARBOHYDRATES FUNCTION

• Energy Source and fuel• Rich in fibre content, help to prevent

constipation• Help in modulation of immune system• In hepar act as detoxification in certain

toxic subtances.

KINDS OF CARBOHYDRATES TEST

• Molisch TestTo prove the present of carbohydrate. Positive

when purple appear.• Selliwanof Test

To different between aldose and ketose. Positive when red appear.

• Benedict TestTo identify aldehyde groups, positive when

red brick appear.• Fehling Reagen

To identify aldehyde groups, positive when red brick appear.• Iodine Test

To identify polysaccharide. Positive when blue-black appear. Different polysaccharides can give other colors like brown.