Lecture22

Lecture22 - ecture 22 11/23/11 Background reading: Berg, et...

Info iconThis preview shows pages 1–5. 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
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ecture 22 11/23/11 Background reading: Berg, et al: Pages 328 - 340 Garrett and Grisham: Pages 219 - 220 Pages 227 - 228 Outline: • Polysaccharides • Classes of glycans • N-linked glycoproteins • O-linked glycoproteins • Glycosaminoglycans • Glycolipids • Examples of biologically relevant glycans • Lectins • Polysaccharides Large polymers of monosaccharides. Glycogen and starch are both large polymers of glucose and play important roles in energy storage. Both of these polysaccharides contain glucose residues linked with α-1,4-glycosidic bonds. They also contain branches in which the glucose chains are linked with α-1,6-glycosidic linkages. Glycogen, which is in animals, contains more branches (about one branch every 10 sugars) than starch which has about one branch every 30 sugars. Another important polysaccharide of glucose is cellulose , which is a linear polymer of β-1,4-linked glucose residues. The strands of cellulose are linear due to the β-1,4-glycosidic linkage and these strands hydrogen bond with one another to form fibers that have a high tensile strength. Cellulose plays an important structural role in plant cell walls. ¡ Classes of glycans Glycans – this generic term is used to designate any sugar or assembly of sugars, in free form or attached to another molecule. Within the past several decades it has become clear that many glycans, particularly those of eukaryotes, are covalently attached to other macromolecules such as proteins and lipids. Two of these classes of glycans are described below: N-glycosidic bond • N –linked glycoproteins Almost all proteins found outside the cell have been found to contain oligosaccharides that are covalently added to the proteins as they pass across the endoplasmic reticulum into the secretory system of the cell.secretory system of the cell....
View Full Document

This note was uploaded on 01/15/2012 for the course BIS 102 taught by Professor Hilt during the Fall '08 term at UC Davis.

Page1 / 14

Lecture22 - ecture 22 11/23/11 Background reading: Berg, et...

This preview shows document pages 1 - 5. Sign up to view the full document.

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