Hemiacetal Formation and Anomers Quiz

Hemiacetal Formation = Reaction of aldehydes/ketones with alcohol to give an alcohol and ether attached to the same carbon Anomers = Cyclic monosaccharides that differ only in the positions of the substituents on the anomeric (hemiacetal) carbon atom Pyranose = A cyclic monosaccharide containing a six-atom ring Intramolecular Hemiacetal Formation = Formation that occurs when the aldehyde (or ketone) are attached in the same chain

Cyclic Hemiacetals Form Readily = When hydroxyl and carbonyl groups are part of the same molecule Alpha and Beta Anomers = Cyclic monosaccharides that always produce two stereoisomers Anomeric Carbon Atom = The hemiacetal carbon atom present in a cyclic monosaccharide structure Pyranose Structure = A cyclic monosaccharide containing a six-atom ring

Cyclic Monosaccharide Formation = Produces two stereoisomers—an alpha form and a beta form Polysaccharides = Long chains of monosaccharide units linked by glycosidic bonds Disaccharides = Formed by the condensation of two monosaccharides Oligosaccharides = Short carbohydrate chains composed of 3-10 monosaccharide units

Hemiacetal formation = Formation of a cyclic form of a carbohydrate with an alcohol group and an aldehyde or ketone group Pyranose structure = Six-membered ring structure found in carbohydrates Furanose structure = Five-membered ring structure found in carbohydrates Haworth projection = 2D representation of a 3D cyclic carbohydrate structure

Disaccharides = Carbohydrates composed of two simple sugar molecules linked by a glycosidic bond Oligosaccharides = Carbohydrates containing from three to ten units of simple sugars Polysaccharides = Complex carbohydrates made up of many simple sugar units Anomers = Isomers that differ at the configuration around the hemiacetal or hemiketal carbon atom

Homopolysaccharides = Carbohydrates composed of repeating units of a single sugar or its derivative Heteropolysaccharides = Carbohydrates made up of different types of sugars or their derivatives Chirality center = A carbon atom in a carbohydrate molecule with four different groups bonded to it Fischer projection = A way to represent the 3D structure of carbohydrates in a 2D format

Monosaccharides = Simple sugars with one type of sugar molecule or its derivative Dihydroxyacetone = The only exception among carbohydrates that lacks chirality centers Glycan = Another term for a form in which most natural carbohydrates occur Glycosidic bond = The linkage between monosaccharides in disaccharides or polysaccharides

Pyranose = 6-membered ring structure Furanose = 5-membered ring structure Hemiacetal formation = Reaction involving an alcohol and an aldehyde/ketone Anomers = Epimers that differ at the anomeric carbon

α-L-ribofuranose = Haworth projection showing -OH of C4 to C1 α-D-tagatopyranose = Haworth projection showing -OH of C5 to C1 β-D-psicofuranose = Haworth projection showing -OH of C4 to C2 β-D-galactopyranose = Haworth projection showing -OH of C4 to C1

Oxidation of glucose = Produces gluconic acid Oxidation of galactose = Produces galactonic acid Weak oxidizing agents = Tollens and Benedict’s solutions Reducing sugar definition = Carbohydrate giving positive tests with Tollens and Benedict’s solutions

Disaccharides = Consist of two monosaccharide units linked together Oligosaccharides = Short chains of monosaccharides (3-10 units) Polysaccharides = Long chains of monosaccharides (more than 10 units) Aldaric acids = Produced by strong oxidation, containing two carboxylic acid groups

Glucose oxidation = Gluconic acid production Galactose oxidation = Galactonic acid production Tollens solution test = Glucose reducing Ag+ ion to Ag Benedict’s solution test = Glucose reducing Cu2+ ion to Cu+ ion

Monosaccharide oxidation with weak agents = Produces aldonic acids Strong oxidizing agents on monosaccharides = Produce dicarboxylic acids Polyhydroxy dicarboxylic acids definition = Aldaric acids resulting from oxidation of both ends simultaneously Oxidation at aldehyde end of aldose = Forms aldonic acid