Chapter7 student - Carbohydrates Carbohydrates Molecules...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Carbohydrates Carbohydrates Molecules for Structure and Energy Storage 1 MCDB310 – Chapter 7: Carbohydrates Monosaccharides • one sugar unit • aldehydes or ketones with two or more hydroxyl groups • carbons onto which these are attached are chiral centers • D-glucose (dextrose) most common • names end in ‘ose’ Oligosaccharides • short chains of sugars joined with glycosidic bonds • disaccharides are most abundant • sucrose is common = D-glucose + D-fructose • names end in ‘ose’ Carbohydrate Classes 2 MCDB310 – Chapter 7: Carbohydrates Polysaccharides • usually >20 monosaccharides linked together (up to 1000s) • sugar chains can be linear or branched • starch and cellulose: glucose polymers that differ greatly in structure and function Carbohydrate Classes 3 MCDB310 – Chapter 7: Carbohydrates • backbones are unbranched carbon chains with single bonds • usually contain multiple chiral carbon atoms • can be open-chain or cyclic • open forms have a carbonyl group – aldehyde → aldose – ketone → ketose • monosaccharide names: Type of carbonyl group and number of carbon atoms Monosaccharides 4 MCDB310 – Chapter 7: Carbohydrates aldehyde = aldose 3 C atoms = triose aldotriose Examples of Monosaccharides 5 MCDB310 – Chapter 7: Carbohydrates • chiral carbon atoms: Rotate the plane of polarized light • glyceraldehyde has 1 chiral center → 2 enantiomers (D and L) • 2 n stereoisomers for a molecule with n chiral centers Stereochemistry of Monosaccharides D L D/L Configuration: • based on the chiral center most distant from the carbonyl carbon • those with the same configuration as D-glyceraldehyde are D-isomers 6 MCDB310 – Chapter 7: Carbohydrates • carbons are numbered beginning at the carbonyl carbon end • epimers : Isomers that differ only in configuration of a single carbon (e.g. D-glucose and D-mannose, D-glucose and D-galactose) Epimers 7 MCDB310 – Chapter 7: Carbohydrates • all monosaccharides with >5 carbons are cyclic in aqueous soln • carbonyl carbon forms hemiacetal/hemiketal with internal hydroxyl group Cyclic Isoforms of Monosaccharides 8 MCDB310 – Chapter 7: Carbohydrates • D-glucose forms an intramolecular hemiacetal between hydroxyl at C-5 and aldehyde at C-1 • results in 2 anomers (isomers): α-D-glucopyranose and β-D-glucopyranose • 6-membered ring: Pyranose Mutarotation of Glucose 9 MCDB310 – Chapter 7: Carbohydrates • aldohexoses and aldopentoses form 6-membered ring: Pyranoses • ketohexoses form 5-membered ring: Furanoses Pyranoses and Furanoses 10 MCDB310 – Chapter 7: Carbohydrates •...
View Full Document

This note was uploaded on 04/05/2009 for the course MCDB 310 taught by Professor Walter during the Spring '09 term at University of Michigan.

Page1 / 40

Chapter7 student - Carbohydrates Carbohydrates Molecules...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online