BIOC312 Lecture Notes - Lecture 7: Glycosidic Bond, Fischer Projection, Anomer
28 Jul 2016
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Document Summary
Carbohydrates (hydrate of carbon) have empirical formulas of (ch2o)n where n >= 3. Monosaccharides have two families; aldoses and ketoses. trioses (3c sugars) above are the smallest and simplestmost important monosaccharides in the body are structurally related to above trioses. Fischer projection; horizontal bonds point out of the plane. Vertical bonds are bonds pointing into the plane. Naming d or l is determined by chiral carbon furthest away from aldehyde or ketone. Fischer projection; useful for understanding stereochemistry but common monosaccharides are cyclic. Aldehyde or ketone group reacts with an alcohol group present in chain to produce rings (hemicetals or hemiketals) Two anomers are designated alpha ( ) or beta ( )- see examples in book lomoarcpsd. Glycosidic bond forms when the anomeric carbon reacts with an oh group on 2nd monosaccharide (hemicacetal acetal) Homoglycans- polysaccharides containing only one type of monosaccharide. Heteroglycans- polysaccharides containing residues of more than one type of monosaccharide. Starch is a mixture of amylase and amylopectin.
