Monosaccharides (OpenStax Biology 2e)
Monosaccharides (mono- = “one”; sacchar- = “sweet”) are simple sugars, the most common of which is glucose. In monosaccharides, the number of carbons usually ranges from three to seven. Most monosaccharide names end with the suffix -ose. If the sugar has an aldehyde group (the functional group with the structure R-CHO), it is an aldose, and if it has a ketone group (the functional group with the structure RC(=O)R’), it is a ketose. Depending on the number of carbons in the sugar, they can be trioses (three carbons), pentoses (five carbons), and/or hexoses (six carbons).– Monosaccharides are the simplest form of sugar and the most basic units of what biomolecules?
The chemical formula for glucose is C6H12O6. In humans, glucose is an important source of energy. During cellular respiration, energy releases from glucose, and that energy helps make adenosine triphosphate (ATP). Plants synthesize glucose using carbon dioxide and water, and glucose in turn provides energy requirements for the plant. Humans and other animals that feed on plants often store excess glucose as catabolized (cell breakdown of larger molecules) starch.Monosaccharides, largely hexoses and pentoses, require no intestinal digestion prior to absorption, but oligosaccharides must be hydrolyzed to monosaccharides before they can be absorbed.
Galactose (part of lactose, or milk sugar) and fructose (found in sucrose, in fruit) are other common monosaccharides. Although glucose, galactose, and fructose all have the same chemical formula (C6H12O6), they differ structurally and chemically (and are isomers) because of the different arrangement of functional groups around the asymmetric carbon. All these monosaccharides have more than one asymmetric carbon.– What is a polysaccharide consisting of polymerized galactose?
Glucose, galactose, and fructose are isomeric monosaccharides (hexoses), meaning they have the same chemical formula but have slightly different structures. Glucose and galactose are aldoses, and fructose is a ketose.Glucose and fructose occur not only in living cells, but also in the xylem sap of certain trees such as maples and birches.
Monosaccharides can exist as a linear chain or as ring-shaped molecules. In aqueous solutions they are usually in ring forms. Glucose in a ring form can have two different hydroxyl group arrangements (OH) around the anomeric carbon (carbon 1 that becomes asymmetric in the ring formation process). If the hydroxyl group is below carbon number 1 in the sugar, it is in the alpha (α) position, and if it is above the plane, it is in the beta (β) position.– What is a monosaccharide containing one ketone group per molecule?
Clark, M., Douglas, M., Choi, J. Biology 2e. Houston, Texas: OpenStax. Access for free at: https://openstax.org/details/books/biology-2e
Research Article: A co-utilization strategy to consume glycerol and monosaccharides by Rhizopus strains for fumaric acid production
Date Published: April 30, 2018 Publisher: Springer Berlin Heidelberg Author(s): Sylwia Kowalczyk, Elwira Komoń-Janczara, Agnieszka Glibowska, Adam Kuzdraliński, Tomasz Czernecki, Zdzisław Targoński. http://doi.org/10.1186/s13568-018-0601-8 Abstract: The ability of Rhizopus oryzae to produce fumaric acid in the presence of glycerol and/or various monosaccharides as carbon sources was examined for seventeen different strains of this fungi. These strains … Continue reading
Research Article: Pyranose Dehydrogenase Ligand Promiscuity: A Generalized Approach to Simulate Monosaccharide Solvation, Binding, and Product Formation
Date Published: December 11, 2014 Publisher: Public Library of Science Author(s): Michael M. H. Graf, Lin Zhixiong, Urban Bren, Dietmar Haltrich, Wilfred F. van Gunsteren, Chris Oostenbrink, Alexander MacKerell Abstract: The flavoenzyme pyranose dehydrogenase (PDH) from the litter decomposing fungus Agaricus meleagris oxidizes many different carbohydrates occurring during lignin degradation. This promiscuous substrate specificity makes … Continue reading
Research Article: Characterization of Chlorella sorokiniana growth properties in monosaccharide-supplemented batch culture
Date Published: July 3, 2018 Publisher: Public Library of Science Author(s): Shuaijie Chai, Jianan Shi, Teng Huang, Yalu Guo, Jian Wei, Meicen Guo, Liyun Li, Shijuan Dou, Lijuan Liu, Guozhen Liu, Yiu Fai Tsang. http://doi.org/10.1371/journal.pone.0199873 Abstract: To reveal growth properties of Chlorella sorokiniana UTEX 1230, four monosaccharides (glucose, fructose, galactose and xylose) were individually supplemented … Continue reading
Research Article: Heterogeneity in the expression and subcellular localization of POLYOL/MONOSACCHARIDE TRANSPORTER genes in Lotus japonicus
Date Published: September 20, 2017 Publisher: Public Library of Science Author(s): Lu Tian, Leru Liu, Yehu Yin, Mingchao Huang, Yanbo Chen, Xinlan Xu, Pingzhi Wu, Meiru Li, Guojiang Wu, Huawu Jiang, Yaping Chen, Hernâni Gerós. http://doi.org/10.1371/journal.pone.0185269 Abstract: Polyols can serve as a means for the translocation of carbon skeletons and energy between source and sink … Continue reading