1. Biochemistry Carb. Lecture 3Carb. Lecture 3

5. Epimers: Sugar which are differ from each other only in the configuration around one carbon atom are called Epimer. Mannose and glucose are epimers at C 2, galactose and glucose are epimers at C 4 Epimers : – stereoisomers that differ only in configuration about one chiral center.

10. Mutarotation: Aldo hexose when dissolved in water the optical rotation gradually changed until constant rotation of sugar is reached this is called mutarotation.

12. Cyclic structure of monosaccharide all monosaccharide have a cyclic hemiacetal structure. It is (the intra molecular reaction of hydroxyl group in carbon 5 with the carbonyl group forming a cyclic hemiacetal with a 6 member ring containing one oxygen and 5 carbon atom) this is called (( Hawarth Formula )). The hawarth formula at D(+) glucose can exist as two isomers because a new cheril center is created at carbon no. 1 to form a cyclic hemiacetal, the new cheril carbon is called ( anomeric carbon ) as result there are two isomers of D glucose, α D glucose and B D- glucose.

13. α-D-glucose in which the hydroxyl group at the anomeric carbon is below the place of the ring while in β-D glucose the anomeric carbon is above the place of the ring. Hemiacetal formation also occur with D- mannose, D- galactose form 6 member ring like glucose. While D-fructose is found as 5 member ring hemiketal. Monosaccharide exist in two cyclic form

14. Pyranose (6member ring) Aldohexose Furanose (5 member ring) Ketohexose Pyranose, furanose, respectively hawarth structural formula

16. α and β form of glucose are formed by hemiacetalization. Formation of hemiacetyl is a condensation reaction between aldo group at C 1 and OH group at C 5 at the same compound forming ring structure. Glycogen is synthesized from α D glucopyranose whereas cellulose is synthesized from β-D glucopyranose.

21. Thank YOU