Download Structure,Classification Of Carbohydrate

Structure,Classification
Carbohydrate !!
Of
CARBOHYDRATE
Carbohydrates are energy- rich organic compounds that contain
the elements carbon, hydrogen & oxygen in 1:2:1 ratio.
The general empriral formula for a carbohydrate is CH2O
SOURCE OF CARBOHYDRATES
Carbohydrates are found in a wide array of both healthy &
unhealthy foods.
Example: Cereal gains, vegetables, fruits, sugar, vit B,
table sugar, syrup, honey etc.
CLASSIFICATION OF CARBOHYDRATES
According to the number of basis sugar or saccharide units
incorporated in the molecule — carbohydrates can be classified
into monosaccharide, oligosaccharide & polysaccharide
Monosaccharides are five types
Trioses
Tetrodes
Pentodes
Hexoses
Heptoses
Oligosaccharides are two types
Disaccharides
Trisaccharides
Polysaccharides are two types
Structural polysaccharides
Storage polysaccharides
MONOSACCHARIDE
Monosaccharide is the simplest form of carbohydrates.
They consist of one sugar.
They are usually colourless.
They are soluble in crystalline solid & insoluble in
solvents.
Backbone of monosaccharide is unbranched carbon chain.
Most have sweet taste.
They cannot be further hydrolyzed into simple
carbohydrates.
Those monosaccharides that contain an aldehyde group are
called aldoses. E.g. glucose
Those containing a ketone group are ketoses. E.g.
fructose.
Monosaccharide are categorized by the number of carbon &
whether an aldehyde / ketone.
TRIOSES
Simplest monosaccharide.
Contains three carbon atoms
E.g. Glyceraldehyde & Dihydroxyacetone
TEROSES
Contain four carbons
They have either a functional aldyde group in position 1
or functional ketone group in position 2.
E.g. D-Erythrose
PENTOSES
Contain five carbons.
Aldopentoses have an functional aldehyde group at
position 1 & ketopeptoses have an functional ketone
group at position 2 / 3
E.g. Xylose, Ribulose, Arabinose, Deoxyribose.
HEXOSES
Contain six carbons.
Aldohexoses having functional aldehyde group at position
1 & ketohexoses having functional ketone group at
position 2.
E.g. Glucose, Fructose.
HEPTOSES
Contain seven carbons.
Either aldoheptoses have a functional aldehyde group in
position 1 or ketoheptoses have a functional ketone
group in position 2
E.g. sedoheptulose, Mannoheptulose.
OLIGOSACCHARIDE
Oligosaccharide is a saccharide polymer containing a
small number typically three to ten component sugar
The name is derived from Greek word oligos meaning “a
few” & sacchar which means “sugar”
They generally found either O or N-linked to compatible
amino acid side chains in protein / in lipids
They joined together by a specific glycosidic bond
Oligosaccharides are further subdivided based in number
of monosaccharide units.
DISACCHARIDE
Composed of two monosaccharide.
Formed when two sugars are joined together & one
molecule of water is removed.
E.g. Sucrose, Maltose, Lactose.
TRISACCHARIDE
Composed of three monosaccharide with two glycosidic
bonds connecting them.
Glycosidic bond can be formed between any hydroxyl
groups on the specialised monosaccharide.
E.g.
Erlose
POLYSACCHARIDE
When ten or more sugar monomers are linked together
called polysaccharides.
They are non reducing carbohydrates.
They are not sweet in taste.
Polysaccharides are two types.
STRUCTURAL POLYSACCHARIDES
All the monomers are the same in the homo- polymer,
synthesized from beta glucose units.
E.g. Cellulose.
STORAGE POLYSACCHARIDE
All the monomers are different Storage polysaccharide.
E.g. strarch, insulin, Glycogen.
FUNCTION OF CARBOHYDRATES
Main function of carbohydrates is to provide body energy
in the form of glucose.
Carbohydrates are stored as glycogen in animals and
starch in plants. Excess of glucose are converted to fat
for storage.
Pentose sugars are the components of DNA, RNA, and ATP &
NAD etc.
The liver of well-fed animals’ rich in glycogen such
liver is more resistant to certain poison like alcohol
or arcenic & toxins of bacteria than the livers of
under- fed animals with low glycogen reserves.
This is the general notes on Structure and Function of
Carbohydrates.
Thank you for reading.