Chapter 14 Biomolecules, Class 12 Chemistry Chapter 14 Biomolecular, Chemistry Class 12 | Page 2

Biomolecules are the organic compounds which form the basis of life , i . e ., they build up the living system and responsible for their growth and maintenance .
The sequence that relates biomolecules to living organism is
Biomolecules → Organelles → Cells → Tissues → Organs → Living organism .
Carbohydrates
Optically active polyhydroxy aldehydes ( aldcses ) or ketones ( ketoses ) or compounds which on hydrolysis give these units are known as carbohydrates . They are also called saccharides
( Latin Saccharum = sugar ) due to sweet taste of simpler members .
Depending upon their behaviour towards hydrolysis , carbohydrates can be of following three types
Monosaccharides
These cannot be hydrolysed to simpler molecules and further subdivided into tetroses , pentoses or hexoses depending upon the number of carbon atoms . These are also called homopolysaccharides .
Aldotetroses Erythrose , Threose Aldopentoses Xylose , Ribose , Aldohexoses Glucose , Galactose , Ketohexoses Fructose
All naturally occurring monosaccharides belong to D-series .
killiani synthesis is used to convert an aldose into next higher aldose .