2. What is a Carbohydrate
•It is a biomolecule
•It is a macromolecule
•It consists with C, H and O atoms
•General formula – Cx(H2O)y
•It has glycocidic bonds
4. Monosaccharides
• Simple sugars
• Cannot hydrolyze into simple form
• Open chain form and ring form can be
seen
• Has aldehyde group or ketone group
• Can be divided according number of
carbon atoms
5. Number of
Carbon atoms
Name Examples
3 Trioses Dihydroxyacet-
one
4 Tetroses Ribose
5 Pentoses Ribulose
6 Hexoses Glucose
6. Disaccharides
•Formed with two monosaccharides
•Bond between two monosaccharaides –glycosidic bond
•Only ring form involving making disaccharides
•Ex: Maltose glucose + glucose
Sucrose glucose + fructose
Lactose glucose + galactose
7. Polysaccharides
•Polymers of monosaccharides (more than 6 units)
•Two types
Homopolysaccharides
ex: Starch, glycogen, cellulose
Heteropolysaccharides
ex: Mucopolysaccharides
•Only ring form is involving making polysaccharides
8. •Act as a source of energy. Ex: glucose
•Act as energy store. Ex: glycogen
•Building blocks of important macromolecules.
Ex: Ribose in RNA
•Structural constituent in cell wall Ex: cellulose
Roles of carbohydrates
9. Thank You
K S A Chathurangika
Wayamba University of
Sri Lanka
