D- and L- Designation
Sugars are divided into two families: the D-family and the L-family which have definite configurations. These configurations are indicated with respect to glyceraldehyde as the standard. Glyceraldehyde can be presented in two forms:
In the D-configuration -OH is attached to the carbon adjacent to -CH2OH while in the L-configuration – OH is attached to the carbon adjacent to the -OH on the left. The sugar is referred to as D- or L- depending on whether the configuration of the molecule is related to D-glyceraldehyde or L-glyceraldehyde.
It has been found that all naturally occurring sugars are related to the D-chain D-glucose, D-ribose, and D-fructose.
However, it may be noted that D- and L- do not represent dextrorotatory levorotatory. The optical activity of the molecule is represented by (+) and (−) which represents the direction of rotation of the plane polarized light ether dextrorotatory or levorotatory.
Monosaccharides
The branch of chemistry that deals with the molecules involved in living things is called biochemistry. Carbohydrates, proteins, vitamins, and nucleic acids are some of the major components of our body. These are collectively called biomolecules.
A biomolecule is sometimes associated as a biological molecule, a term that refers to molecules found in living objects that are important for one or additional biological processes, analogous to cell division, morphogenesis, or development. Large macromolecules (or polyanions) similar to proteins, carbohydrates, lipids, and nucleic acids, as well as primary metabolites, secondary metabolites, and smaller moieties, similar to natural products, are all examples of biomolecules. Natural material is the more broad term for this type of material. Biomolecules are essential factors of living organisms. While endogenous biomolecules are made within the organism, organisms usually require external biomolecules, such as specific nutrients, to be present.
Carbohydrates are optically active polyhydroxy aldehydes or polyhydroxy ketones or substances that upon hydrolyzed would produce these types of compounds.
Table of Content
- What are Monosaccharides?
- Structures of Monosaccharides
- D- and L- Designation
- Where can we find Glucose?
- Presence of Asymmetric Carbon Atoms
- Examples of Monosaccharides
- Sample Questions on Monosaccharides
- Preparation of Glucose