Carbohydrates are an essential biomolecule for living organisms. They serve many important functions including providing structure, energy storage, and participating in cellular processes. There are three main classifications of carbohydrates - monosaccharides, disaccharides, and polysaccharides. Monosaccharides are the simplest form and include glucose and fructose. Disaccharides are formed from two monosaccharide units and examples include sucrose, lactose, and maltose. Polysaccharides are high molecular weight carbohydrates formed from long chains of monosaccharide units, such as starch, glycogen, and cellulose. Carbohydrates provide structure to plants and serve as an energy reserve in plants and animals.

1. Shri Shankaracharya Mahavidyalaya, Junwani , Bhilai
Dr. Sonia Bajaj
(Head of Department)
CARBOHYDRATES

2. SYNOPSIS
Introduction
Definition
Function
Classification of Carbohydrate
Structure & Properties of Monosaccharide
Structure & Properties of Disaccharide
Structure & Properties of Polysaccharide
Conclusion
Reference
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3. Introduction
A carbohydrate is a biomolecule consisting of carbon, hydrogen and oxygen atom usually with the
hydrogen oxygen atom ratio 2:1.
The term carbohydrates was originally coin from for the class of compounds as most of them where
'hydrates of carbon' and could be represented by the general Formula C x (H2O)y.
The term carbohydrates are also known as (saccharide or sugar) since many of those are of relatively
small molecular weight having a sweet taste.
They are widely distributed in both plants and animals.
They are indispensable for living organisms serving as skeletal structure in plants and also in insects.
They also occur as food reserve in the storage organ of plants and in the liver and muscles of animals.
Plants are considerably richer in carbohydrates in comparison to the animals.
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4. Definition
Carbohydrates may be defined as polyhydroxyaldehyde or
ketones or compounds which produces them on hydrolysis.
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5. Classificationof Carbohydrates
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6. Structure & Properties of Monosaccharide
“Mono’’ means one and “saccharon” means sugar.
The monosaccharides often called simple sugar are compounds which posses a free aldehyde
(–CHO)or ketone group (=CO) and two more hydroxyl group (-OH).
Monosaccharides that contain an aldehyde group are referred to as an aldose. Those that
contain a ketone group are referred to as a ketose.
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7. PROPERTIES
1. Reaction with Carbonyl group:-
Includes
 Reduction
When monosaccharide reacts with sodium amalgam and water it produces polyhydric alcohol.
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8.  Oxidation
a) Aldoses
When glucose reacts with CuSO4, bromine water or silver oxide it produces monocarboxylic acid in
which number of carbon atom does not changes
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9. b) Phenylhydrazine reaction
When Phenylhydrazine reacts with monosaccharide it gives osazone formation.
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10. c) Hydroxyl Group reaction
Simple sugars react with hydroxylamine to yield oximes.
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11. d) Reducing reaction
Glucose and Fructose very easily oxidizes.
When glucose reacts with fehling of toluene solution it makes Red precipitate.
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12. e) Hydrogen Cyanide Reaction
When glucose reacts with hydrogen cyanide (HCN) it gives glucose cyanohydrin.
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13. 2. Reaction with Alcoholic group
a) Action of Metallic Hydroxides
Metal Hydroxide reacts with glucose and fructose and form glucose and fructose metallic nutrients.
Metallic nutrient such as Cu(OH)2, Ca(OH)2 ,Ba(OH)2 etc,.
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14. b) Action of PCl5
When glucose reacts with PCl5 it forms Pentachloro fructose.
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15. 3. Fermentation
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16. 4. Contains Asymetric carbon atom
All monosaccharides contain one or more more asymmetric carbon atom accept the kitotriose and
dihydroxyacetone.
All compound having one or more asymmetrical carbon atoms shows optical activity and
streoisomerism.
5. Streoisomerism- Compounds having same structure formula but different in spatial configuration
are known as streoisomerism
6. D & L Isomers
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17. 7. Epimers
8. Mutarotation
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18. PhysicalPropertiesofMonosaccharides
1. After dissolving in water all monosaccharides give a sweet taste.
2. All monosaccharides move across plasma membrane.
3. All monosaccharides are soluble in water. When they dissolve in water they would take up the ring
form. This is the cause for their solubility in water.
4. When monosaccharides are dissolved in water they would initiate the lowering of water potential of
the solution.
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19. Structure&PropertiesofDisaccharides
These are naturally found oligosaccharide.
(Fructose + glucose) is found in sweet fruit and honey and some roots of plants.
It is found in ripe grapes with composition 20 to 30% and therefore it is called also called grape sugar.
Disaccharide are those carbon atom which are made by the two atoms of monosaccharides.
Examples- Sucrose, Lactose, Maltose etc,.
C6H12O6 + C6H12O6 C12H22011 +H2O
Glucose Glucose Maltose
C6H12O6 + C6H12O6 C12H22011 +H2O
Glucose Fructose Sucrose
Glucose + Galactose C12H22011
Lactose
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20. Sucrose
It is also called table sugar, sugar of Cane, sugar of beetroot etc,.
Sucrose is mostly found in plants which takes photosynthesis and
that is why it is one of the food which is found in crystal form.
This is made by the juice of Cane or the roots of beetroot.
It contains 50-20 % of sucrose.
In India sugar is made by sugarcane and in Cuba, Ruse and Java it is
made by beetroot.
Its atomic formula is C12H22O11.
It is colourless crystal material.
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21. Maltose
In simple words it is also called Malt sugar.
It is developed by the decomposition of starch in plant.
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22. Lactose (Milk Sugar)
It is a sugar composed of galactose and glucose.
lactose makes up around 2-8% of milk.
The name come from latin word milk and “ose” used to
name sugar.
The component is white, water soluble, non-hygroscopic
solid with a mildly sweet taste.
It is used in the food industry.
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Lactose

23. ChemicalProperties
1. Action of Heat
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24. 2. Fermentation
3. Acetylation
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25. 4. Hydrolysis
5. Formation of Metallic Derivatives
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26. 6. Action of Conc. Hydrochloric acid
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27. Physical Propertiesof Disaccharides
All disaccharides are soluble in water and give the sweet taste.
All disaccharide cannot pass plasma membrane of the cell or there is no career enzyme that can
carry disaccharides to move across the plasma membrane.
When disaccharides are dissolve in water they would cause the lower of water potential of the
solution.
Among disaccharides maltose and lactose are reducing sugar while sucrose is non reducing
sugar.
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28. Polysaccharides
Polysaccharides are high molecular weight carbohydrates which on hydrolysis yield mainly
monosaccharide or product related to monosaccharides.
A great majority of carbohydrates occur in nature as polysaccharide.
Example- Starch, Glycogen, Cellulose etc,.
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29. 1. Starch
Occurrence- Starch occurs widely in plants especially in roots,tubers,
seeds and fruits as a carbohydrates storage product and energy source.
It is present in cerials, legumes, potatoes and other vegetables.
It is found in colourless plastids in storage tissue and in stroma of
chloroplast in plants.
More than half of the carbohydrate is ingested by humans as starch.
It is usually present inside the plant cell as insoluble granules which may
be spherical, lens-shaped or ovoid.
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30. Chemistry of Starch
Natural stars consists of two components:
Amylose (15-20%) a long unbranched straight chain
component.
Amylopectin (80-85%) a branch change polysaccharide
Potato and serial starch are 20-30% of amylose and 70-80%
of amylopectin.
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31. Structure
Starch
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32. Properties
Starch is white soft amorphous powder and lacks sweetness.
It is insoluble in water, alcohol and ether at ordinary temperature.
Starch on partial hydrolysis by boiling with water under pressure at
about 250°C break down into large fragments called Dextrin.
Hydrolysis
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33. 2. Glycolysis
Occurrence- It is major reserve food in animals
hence called animals starch) and also in many
fungi and bacteria due to its been osmotically
inactive.
Glycogen is stored in liver and muscles of animal.
It is especially abundant in liver where it may
attain up to 7% of the wet weight.
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Structure

34. Properties
It is white amorphous, tasteless powder and is more soluble in water.
It is non reducing sugar and gives red colour with iodine.
The red colour however disappears on boiling and reappears on
cooling.
Hydrolysis
On hydrolysis glycogen yield maltose.
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35. 3. Cellulose
Occurrence- Cellulose is not only the most abundant
extracellular structural polysaccharide of plant world
but is also the most abundant of all molecules in the
biosphere.
It is present in all land plants but is completely
lacking the meat, egg, fish and milk.
Cellulose occurs in the cell wall of plant where it
contributes in a major way to the structure of the
organism.
The molecular weight of cellulose ranges between
20000 and 2,00,000 does corresponding 21250-
12500 glucose residues per molecule.
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Structure

36. Properties
It is fibrous tough white solid insoluble in water but soluble in ammoniacal cupric hydroxide
solution.
It gives no colour with Iodine.
It lacks sweetness.
Although insoluble in water, cellulose absorbs water and add to the bulk of the fecal matter.
Hydrolysis
Cellulose is relatively inert material and is completely degraded only under the most drastic
condition.
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37. Functions
1. They are most abundant dietary source of energy for all organism.
2. It is precursor for many organic compounds.
3. Carbohydrate participate in the structure of cell membrane and cellular function.
4. They are structural component of many organism.
5. Carbohydrate also serve as the storage form of energy.
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38. Reference
1. Textbook of Biochemistry by U.Satyanarayana.
2. Fundamental of Biochemistry by J.L.Jain.
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