Monosaccharides : Monosaccharides are classified based on the position of their carbonyl group and the number of carbons in the backbone. Aldoses have a carbonyl group indicated in green at the end of the carbon chain, and ketoses have a carbonyl group in the middle of the carbon chain.
Trioses, pentoses, and hexoses have three, five, and six carbon backbones, respectively. Glucose C 6 H 12 O 6 is a common monosaccharide and an important source of energy. During cellular respiration, energy is released from glucose and that energy is used to help make adenosine triphosphate ATP. Plants synthesize glucose using carbon dioxide and water, and glucose, in turn, is used for energy requirements for the plant.
Galactose a milk sugar and fructose found in fruit are other common monosaccharides. Although glucose, galactose, and fructose all have the same chemical formula C 6 H 12 O 6 , they differ structurally and stereochemically. This makes them different molecules despite sharing the same atoms in the same proportions, and they are all isomers of one another, or isomeric monosaccharides.
Glucose and galactose are aldoses, and fructose is a ketose. During this process, the hydroxyl group of one monosaccharide combines with the hydrogen of another monosaccharide, releasing a molecule of water and forming a covalent bond. A covalent bond formed between a carbohydrate molecule and another molecule in this case, between two monosaccharides is known as a glycosidic bond. Glycosidic bonds also called glycosidic linkages can be of the alpha or the beta type.
Disaccharides : Sucrose is formed when a monomer of glucose and a monomer of fructose are joined in a dehydration reaction to form a glycosidic bond. In the process, a water molecule is lost. By convention, the carbon atoms in a monosaccharide are numbered from the terminal carbon closest to the carbonyl group.
In sucrose, a glycosidic linkage is formed between carbon 1 in glucose and carbon 2 in fructose. Common disaccharides include lactose, maltose, and sucrose. Lactose is a disaccharide consisting of the monomers glucose and galactose.
It is found naturally in milk. There are two enantiomers mirror-image isomers of the sugar — D-glucose and L-glucose, but in living organisms only the D-isomer is found. Explanation: Glucose, galactose, and fructose are carbohydrates, and monosaccharides in particular. The isomers glucose, glactose, and fructose all have the same chemical formula, C6H12O2.
Glucose is an optically active compound as it possesses four asymmetric carbon atoms or the chiral centers. The net optical rotation of a racemic mixture becomes zero. Thus structure 1 is the same as 9 and 7 is the same as They are meso compounds and optically inactive. Statement-2 : Alderic acid produced from allose II has plane of symmetry. Glucose can be found in nature as either D-Glucose or L-Glucose. The main difference between D and L Glucose is that D-Glucose rotates plane polarized light clockwise whereas L-Glucose rotates plane polarized light anticlockwise.
Glucose is by far the most common carbohydrate and classified as a monosaccharide, an aldose, a hexose, and is a reducing sugar. It is also known as dextrose, because it is dextrorotatory meaning that as an optical isomer is rotates plane polarized light to the right and also an origin for the D designation. D- and L- notation provides a quick shorthand for designating enantiomers. Dec 14, Glucose and galactose are diastereoisomers. Explanation: The structures of glucose and galactose are Diastereoisomers are Optical isomers of each other.
Not mirror images of each other. Not superimposable on each other. They are therefore diastereoisomers. Related questions What are diastereomers?
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