classification of monosaccharides,.pptx

Classification of Monosaccrides

1. C lassification of monosaccharide and its structure Ms.J.Mythili Assistant professor Department of Biotechnology Bon secours college for women Thanjavur

2. Monosaccharides are poly hydroxy aldehydes or ketones which cannot be further hydrolyzed to simple sugars (Mono- single, saccharide –sugar) Monosaccharides are simple sugar .they are sweet in taste. They contain 3 to 10 carbon atoms ,2 or more hydroxyl (OH)group s and one aldehyde (CHO)group ,or one ketone group (CO) group. They are represented by the formula of (CH2O)n. The monosaccharides contain one or more asymmetric carbon atoms. the asymmetric carbon atoms attached to four different groups. Monosaccharides

3. Monosaccharides are classified in two ways ,first up all based on the number of carbon atoms present in in them , monosaccharides are classified in to Trioses containing 3 carbon atoms C3 H6 O3 Tetroses containing 4 carbon atoms C4 H8 O4 Pentoses containing 5 carbon atoms C5 H10 O5 Hexoses containing 6 carbon atoms C6 H10 O6 Hep toses containing 7 carbon atoms C7 H10 O7 Secondly based on the type of carbonyl group ,monosaccharide s classified in to two types, Namely aldoses having an aldehyde group and ketoses having a ketone group . Both aldoses and ketoses have the suffix- ose . Inorder to differentiate them, ketoses are named with suffix- ulose . C lassification of Monosaccharides

4. Glucose is a simple monosaccharide.it is hexose .It is an aldohexose The molecular formula of glucose is C6 H12 O6. The glucose may be represented by two structures .they are 1.Straight chain structure or open chain structure 2.Cyclic structure or ring structure 1.Straight chain structure or open chain structure. In straight chain structure ,the carbon atoms o glucose are arranged in straight chain line.it is also called open chain structure because the two ends remain separate and they are not linked. Fitting and Baeyer proposed in straight chain structure .It contains aldehyde group (CHO) and hydroxyl groups (OH). According to fitting Baeyer,the aldehyde group is at one end and four CHOH groups in between. S tructure of monosaccharides

5. C6H12O6 CHO CHO I I (CH.OH)4 H - C -OH I I CH2OH HO - C- OH Molecular I formula fitting H-C-OH Baeyer I straight H-C-OH chain I CH2 OH Fisher straight chain structure Structure of glucose

6. Fisher’s proposed another straight chain structure .according to fisher’s the aldehyde group is placed at one end and the remaining carbon atoms are arranged one behind the other. The last carbon atoms contains two hydrogen atoms and other OH Group (H2OH). The remaining carbon atoms contain H atom on one side and OH group on the other side. The carbon atoms are numbered from the aldehyde group .The carbon atom of the aldehyde group is the carbon atom number 1 and carbon atom containing H2 OH is the carbon atom number 6 in (Hexoses). Straight chain structure

7. In cyclic structure ,the atoms are arranged in the form a ring .Haworth (1929) an English chemist , deviced the ring structure .Hence the ring structure is referred to as Haworth’s projection formula. The sugar molecules exist in two types of rings .they are pyranose ring and furanose ring. The ring structure of monosaccharides may be similar to either pyran or furan and accordingly the monosaccharide is said to occur in pyronose orfyronose form. 2 .Cyclic structure or Ring structure

8. Thankyou