BIOC12H3 Lecture Notes - Antigen, Hexose, Gram-Positive Bacteria
Document Summary
Bioc12fall2012 lecture 8: carbohydrates and glycoproteins (chapter 7) Functions: mainly energy source, protection as structural materials, intercellular communication, stabilization of protein structures (example: there is a sugar attached to antibodies which stabilizes their structures) Monosaccharides: derivatives or aldehyde or ketones aldoses, ketoses, straight chain and contains polyhydroxy alcohols (at least 3 carbon atoms) Aldoses: aldoses contain 3- 6 carbon atoms example glucose, mannose. Cyclic monosaccharide structures and anomeric forms: glucose (an aldose) can cyclize to form a cyclic hemiacetal called pyranose fructose (a ketose) can cyclize to form a cyclic hemiaketa called furanose, the alcohol group and the carbonyl carbon interact. 3 if the hydroxyl on the 5th carbon reacts with the carbonyl carbon then a 6 member ring is formed. 5: there are also more complex modifications, n-acetylneuraminic acid is an important component of glycoproteins, inside cells, most monosaccharides are modified. Rna structured because it contains a deoxysugar (deoxyribose)
