Introduction Carbohydrates are more than just fuel for the body and have other uses. Carbohydrates are hydrocarbons containing one carbonyl group and many alcohol groups. Their polymers can complex or be simple and contain a single repetitive monosaccharide, the roles of the polymers can be multiple, for example structural, storage or even signaling. (Tymoczko et al, 2012 p. 131)MonosaccharidesMonosaccharides come in 2 forms, aldoses and ketoses. There can be up to seven carbon atoms in the chain, however most monosaccharides contain six called hexoses. Monosaccharides undergo optical isomerization and for monosaccharides they are in the D form or the L form. Most of those found in nature are found in the D form. Monosaccharides can have more than one asymmetric carbon so they can have diastereoisomers. Like D-glucose, it contains three chiral carbons so it has 2 epimers, D-mannose an epimer at C-2 and D-galactose an epimer at C-4. (Nelson, et al, 2003, p. 294-297) Monosaccharides exist in a cyclic form when in solution, this is because the aldehyde group reacts with the alcohol group on the same monosaccharide to form a hemiacetal. Ketoses have the same reaction but with their own ketone group to form hemiketals. They can be pyranoses which are 6-membered cyclics or furanoses, which are 5-membered cyclics. (Tymoczko et al, 2012 p. 133-134) The creation of these rings forms a new asymmetric carbon called anomeric carbon. This anomeric carbon forms 2 anomers, alpha and beta. Beta is above the anomeric carbon, alpha is below. Alpha and beta anomers have mutarotation, where alpha and beta transform into each other through equilibrium. The equilibrium mixture is unique for each monosaccharide. (Nelson, et al, 2003, p. 299) Monosaccharides...... middle of paper......MA, Yao, W., Decicco, C., Tortorella, MD, Liu, R., Copeland , R.A., Magolda, R., Newton, R.C., Trzaskos, J.M. and Arner, E.C. (2003) 'Aggrecan Protects Cartilage Collagen from Proteolytic Cleavage'. Journal of Biological Chemistry, November 14, 278 (46), pp. 45539-45545 DOI 10.1074/jbc.M303737200.Nelson, DL Cox, MM (2003) Lehninger Principles of Biochemistry, 3rd edition, Worth publishers, New York.Tymoczko, JL Jeremy, MB Stryer, L. (2011) Biochemistry a short course , 2nd edition, WH Freeman and Company, New York.Murray, RK Granner, DK Mayes, PA Rodwell, VW (2003) Harpers Illustrated Biochemistry, Lange Medical Books/ McGraw-Hill Medical Publishing DivisionRajic, A (2013) "Carbohydrates: structure and function" [PowerPoint presentation]. IMDBIS 105 Bioscience Available at: https://learn.ucs.ac.uk (accessed: 24 November 2013)