Carbohydrates and Carbohydrate metabolism
Carbohydrates and Carbohydrate metabolism
It is hardly surprising that much of the early biochemical research was concerned with the study of proteins.Proteins form the class of biological macromolecules that have the most well-defined physico- chemical properties and consequently are generally easier to isolate and characterize than nucleic acids,polysaccharides,or lipids. Furthermore,proteins,particularly in the forms of enzymes,have an obvious biochemical function.The central role that proteins play in biological processes has therefore been recognized since the earliest days of biochemistry.In contrast,the task of nucleic acids in the transmission and expression of genetic information was not realized until the late 1940s,the role of lipids in biological membranes was not appreciated until the 1960s,and the biological functions of polysaccharides are still somewhat mysterious. (Donald Judith Voet,1990)
Carbohydrate metabolism
1.Complex carbohydrates are heterogenious and not easy to characterize by physical and/or chemical analysis. 2.Carbohydrates are not genetically determined.Complex structure are build by a sequential addition of monomeres using different enzymes. 3.Carbohydrates have usually passive functions within cells.Thus functional assays to measure its biological activity are difficult to develop. Nevertheless:carbohydrates are essential compounds in all cells 1.Energy metabolism and energy storage. 2.Ribose and deoxyribose as components of RNA DNA. 3.Carbohydrates are essential components of glycoproteins and glycolipids. 4.Carbohydrates are important components of zell walls of bacteria and plants
1. Complex carbohydrates are heterogenious and not easy to characterize by physical and/or chemical analysis. 2. Carbohydrates are not genetically determined. Complex structure are build by a sequential addition of monomeres using different enzymes. 3. Carbohydrates have usually passive functions within cells. Thus functional assays to measure its biological activity are difficult to develop. Nevertheless: carbohydrates are essential compounds in all cells ! 1. Energy metabolism and energy storage. 2. Ribose and deoxyribose as components of RNA / DNA. 3. Carbohydrates are essential components of glycoproteins and glycolipids. 4. Carbohydrates are important components of zell walls of bacteria and plants
Important terms of Carbohydrate Chemistry ●Aldoses Ketoses ●Trioses,Tetroses, Chair and Boat Configurations Pentoses,Hexoses, Furanoses Pyranoses Heptoses Hemiacetals Hemiketals Haworth-/Fischer-Projection Isomeric ●Mutarotation ●Epimeric Forms ●Sugar alcohols Anomeric ●Sugar acids Deoxy sugars,Amino sugars
Aldoses I Ketoses Chair and Boat Configurations Furanoses I Pyranoses Hemiacetals I Hemiketals Haworth- I Fischer-Projection Mutarotation Sugar alcohols Sugar acids Deoxy sugars, Amino sugars Important terms of Carbohydrate Chemistry Isomeric Epimeric Forms Anomeric Trioses, Tetroses, Pentoses, Hexoses, Heptoses
Isomeric structures Isomeric(greak ioouapng):isos equal;meros part Compounds of identical molecular formula but different structures I constitutional isomers structural isomers like ethanol and dimethylether CH3-CH,-OH CHz-O-CH3 ll stereomeric isomers 1.Configurational isomers In stereoisomers the bond structure is the same,but the geometrical positioning of atoms and functional groups with respect to optically active C atoms differs. This class includes enantiomers where different isomers are non-superimposable mirror-images of each other,and diastereomers when they are not.This also in- cludes cis-trans isomers or geometric isomers,respectively
Isomeric structures Isomeric (greak ἰσομερής): isos = equal; meros = part Compounds of identical molecular formula but different structures I = constitutional isomers structural isomers like ethanol and dimethylether CH3 -CH2 -OH CH3 -O-CH3 II = stereomeric isomers 1. Configurational isomers In stereoisomers the bond structure is the same, but the geometrical positioning of atoms and functional groups with respect to optically active C atoms differs. This class includes enantiomers where different isomers are non-superimposable mirror-images of each other, and diastereomers when they are not. This also includes cis - trans isomers or geometric isomers, respectively