NUTR 3210 Lecture Notes - Lecture 6: Anomer, Hemiacetal, Stereospecificity
30 Jan 2017
School
Department
Course
Professor
Document Summary
Reducing sugar if anomeric carbon is free: disaccharides. Two monomers linked by acetyl bond (glycosidic) Homo and hetero (same monomers, different monomers) All carbs have h:o ratio of 2:1. Pentose: components of dna and rna. Aldose/aldohexose: functional group on c1, o in position 6(right) Ketose/ketohexose: fuctional group on c2, o in middle (btw 2 and 5) Same molecular formula and sequence, but differ in 3d space due to chiral carbon atoms. What is a chiral carbon: a carbon with four different groups of atoms attached. Different types: enantiomers (mirror images, disasteromers (not a mirror) Chiral carbon: begins with carbonyl carbon. Fishcher projection: exist in two forms: d vs l. Determined by oh on highest chiral carbon. Right oh = d: number of stereoisomers = 2^n, d-monosaccharides are nutritionally more important because digestive enzymes are stereospecific for d sugars, hemiacetal = monosaccharides with an aldehyde, hemiketal = monosaccharides with a ketone. Rules: non-acetyl ketal ch2oh pointed up, hydroxyl group.
