Number of -OH groups in ribose:
option a : Number of -OH groups in ribose is 4 General rule : Number of -OH groups are always one less than the number of carbons in carbohydrates Glucose (6C) has 5 -OH groups. Ribose (5C) has 4 -OH groups. MONOSACCHARIDES No of C atoms Generic name Example (Ald) No. of OH groups 3 Trioses Glyceraldehyde 2 4 Tetroses Erythrose 3 5 Pentoses RiboseXylose (Epimer of Ribose) Arabinose 4 6 Hexoses GlucoseGalactose Mannose 5
4
5
6
2
Classification of carbohydrate