MCB 150 1st Edition Lecture 4 Outline of Last Lecture I Structures and functions of organelles in a Eukaryotic cells II Macromolecules Outline of Current Lecture III Types of monosaccharides a Hexoses b Trioses c Pentoses IV Polysaccharides a Cellulose b Starch c Glycogen Current Lecture Monosaccharides usually found with 3 5 or 6 carbons in the chain Ex Glucose C H O linear and circular forms Glucose When the carbon 1 is circularized with the H on top in the structural orientation Glucose When the carbon 1 is circularized with the hydroxyl group on top in the structural orientation Circularization of Glucose The transition of the linear form of the glucose to the circular structure Isomers chemical compounds that have the same chemical formula but different structures Common in monosaccharides Other times monosaccharides have SIMILAR formulas not identical structures and functions Hexoses 6 carbon sugars Aldose Glucose Galactose These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Ketose Fructose Trioses 3 carbon sugars Aldose Glyceraldehyde Ketose Dihydroxyacetone Pentoses 5 carbon sugars Aldose Ribose Polysaccharide Disaccharide when two monosaccharides come together to form a simple polysaccharide Glycosidic linkage Covalent bond that joins monosaccharides Disaccharide of 2 hexose sugars has the formula C H O Terminology One monomer is a monosaccharide Two monomers is a disaccharide Three or more is a polysaccharide Hundreds or thousands of monomers is a oligosaccharide Carbohydrates can be modified Linkage of oligosaccharides to other macromolecules Addition of chemical groups Polysaccharides serve as chemical sources of energy or structural compounds Cellulose Starch Glycogen Cellulose Most abundant organic compound on earth Found in plant cell walls Linear and unbranched polymer of glucose o Linked monomers with a 1 4 glycosidic linkages o Hydrogen bonds hold together linear polymers with adjacent strands Starch Found mostly in seeds fruits tubers and roots and stems of plants Used in energy storage Helical polymers if glucose that are either loosely branched or unbranched o Monomers inside chains bonded with an 1 4 glycosidic linkage o Chains connecting with one another by a 1 6 glycosidic link Glycogen Found in muscle and liver cells of animals Used in energy storage Highly branched molecules of glucose helical n shape o Monomers inside chain s linked with a 1 4 glycosidic link o Chains connecting with one another with a 1 6 glycosidic link