Carbohdrates
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This document defines and classifies carbohydrates. Carbohydrates are organic compounds made of carbon, hydrogen, and oxygen that include sugars, starches, and fibers. They are classified into monosaccharides, oligosaccharides, and polysaccharides. Monosaccharides are simple sugars that cannot be broken down further, while oligosaccharides contain 2-10 monosaccharide units and polysaccharides contain over 10 units and are not sweet tasting. Common monosaccharides include glucose and fructose, while examples of polysaccharides are starch, glycogen, cellulose, and chitin. Carbohydrates serve as energy sources for cells and as structural materials in plants.
Carbohdrates
- 1. 1 Carbohydrates By Asghar khan lecturer in Botany GDC Totakan
- 2. CARBOHYDRATES Carbohydrate means "watered carbon" or carbon with attached water molecules Carbohydrates are a group of Organic compounds containing Carbon, hydrogen and oxygen with a ratio of two hydrogens for every oxygen atom. They are also Called Saccharides They are most abundant molecules in nature Defined as Polyhydroxy aldehyde or ketones or Compex substances which on hydrolysis yield Polyhydroxy aldehyde or ketones Examples of carbohydrates are, Glucose, sucrose,Starch, cellulose ,etc By Asghar khan lecturer in Botany GDC Totakan
- 3. Classification of carbohydrates Classified into three groups 1. Monosaccharides 2. Oligosaccharides 3.Polysaccharides Monosaccharides Mono means one and Saccharide means sugar They are simple sugars They have Empirical formula (CH2O)n They Can not be further hydrolyzed into more simple units They are Sweet in taste, easily soluble in water and crystalline
- 4. MONOSACCHARIDES Contains either aldehyde or ketone group. The carbon backbone in monosaccharide comprises of 3 to 7 carbon atoms Their names are ends with ose, with 3 carbon atoms are called trioses, with 4 carbon atoms tetroses and with five carbon atoms are Pentoses and so on. Most monosaccharide form a ring structure in solution
- 6. OLIGOSACCARIDES Oligo means few, saccarides means sugar A saccharide polymer containing a small number (2 to 10) of simple sugar (monosaccaride) linked through gylcosidic bond. Those oligosaccharides which yield two monosaccahrides on hydrolysis are called Disaccaride Three monosaccaride units are called trisaccharide Disaccharides Most common oligosaccaride Less sweet in taste, less soluble in water as compared to monosaccharide Can be hydrolyzed into two monosaccharide units By Asghar khan lecturer in Botany GDC Totakan
- 7. Disaccharides Example of Disaccharide Sucrose (cane sugar),Lactose (milk sugar) , Maltose (malt sugar, found in fruits) Glucose + Fructose synthesis Sucrose +water Glucose+ Glucose synthesis Maltose+ Water Glucose+ Galactose synthesis Lactose +water
- 8. Polysaccharides Complex carbohydrate Are polymers of monosaccharide unit Yields more than ten units of glucose on hydrolysis They are Tasteless, insoluble in water Examples of polysaccharides are Starch, Glycogen, Cellulose,Chitin etc a.Starch: Starch is a polymer of many glucose units. Starch is stored in plant cells Exists in two forms Amylose : unbranched chain of glucose units, more soluble in water Amylopectin : Branched chain of Glucose units, less soluble in water.
- 9. Polysaccharides b. Glycogen are called animal starch They are Polymer of Glucose units (monomers) Extensively Branched structure Stored in animal cells c. Cellulose Most abundant carbohydrate in nature Formed of unbranched chain of Glucose units (monomers) Building material of plant cell wall Human digestive system can not digest cellulose due lack of an enzyme called cellulase Cotton fiber is a pure example of cellulose By Asghar khan lecturer in Botany GDC Totakan
- 10. Polysaccharides
- 11. Polysaccharides d.Chitin Chitin is a polysaccharide Found in exoskeleton of Arthropods, Fungal cell wall Polymer of glucose & an amino group (-NH2) is also attached to each glucose molecule Like cellulose chitin is also not digestible
- 12. Function of carbohydrates 1) Source of energy : Carbohydrates are used as source of energy. During respiration C-H bonds are broken down and energy stored in these bond are release used in various cell functions. 2) Storage molecules : They are stored in cell as reserve food for future use 3) Structural building material : Cellulose is the major structural component of cell wall in green plants while, Chitin is the structural component of exoskeleton of Arthropods. By Asghar khan lecturer in Botany GDC Totakan