Carbohydrates are the most common biomolecules found in living organisms on earth, belonging to the class of organic compounds. Annually, photosynthesis convert over 100 billion cubic meters of CO2 and H2O into cellulose and other plant materials. Living matter is mainly composed of biomolecules formed of water and complex amino acid, lipid, and carbohydrate polymers.Carbohydrates are related to glycoprotein-forming amino acid polymers (proteins) and to lipids as glycolipids. Carbohydrates are one of the main component of DNA and RNA. The presence of sugars is known before life existed on earth. They caramelize and char at higher temperatures. So many sugars formed in alkaline solution from formaldehyde, or synthetic pathways. Formaldehyde condensation has participate in the development of triose, tetrose, pentose, and hexose sugars. Carbohydrates include a comprehensive group of naturally occurring substances which include large number of sugars and sugar derivatives, as well as long chained carbohydrates (polysaccharides) such as starch and cellulose in plants and glycogen in animals. Generally, the main function of carbohydrates in the metabolism of living organisms. The breakdown of carbohydrates represent adequate amounts of energy that needed by each organism for various vital processes. This research is made to give an idea of the sugars (monosaccharide, polysaccharides; their derivatives), their important functions, structure and biological values.
Definition: Carbohydrates are hydrates of carbon, composed of carbon (C), hydrogen (H) and oxygen (O) atoms, more often than not with a hydrogen-oxygen molecule proportion of 2:1 (as in water) and and have the general formula Cx(H2O)y (whereas x=y) ,This equation is for all carbohydrates. A few exemptions exist ; for case , 1-deoxy sugars(ex:Rhamnose C6H12O5) ; 2- Sugar alcohols (ex:Sorbitol C6H14O6) ; 3-Sugar acids (ex:Gluconic acids C6H12O7) ; 4-Amino sugars (ex:Glucosamine C6H13NO5) .Basically it is more particular to see them as aldoses and ketoses.
Importance of carbohydrates
The carbohydrates are a significant source of metabolic energy, both for plants and for food-dependent animals. Apart from the sugars and starch that fulfill this essential nutritional function, carbohydrates also serve as structural material (cellulose), a portion of the energy transport compound ATP, cell surface recognition sites.
A-Monosaccharides
The simplest and smallest carbohydrate unit is the monosaccharide (mono = one, saccharide = sugar), from which disaccharides, oligosaccharides, and polysaccharides are produced,and cannot be hydrolysed to simpler carbohydrates. Monosaccharides are either aldehydes or ketones with many hydroxyl groups; the six-carbon monosaccharides glucose (an aldohexose) and fructose (a keto hexose) have five hydroxyl groups. The carbon atoms which are bound to hydroxyl groups are mostly chiral centres. Simple monosaccharides are called tetroses, pentoses, hexoses, and heptoses, with four, five, six, and seven carbon atoms, respectively. Since these molecules have several asymmetric carbons, they exist as diastereoisomers, as well as enantiomers, isomers that are not mirror images of one another. The D and L symbol, the absolute configuration of the asymmetric carbon the farthest from the aldehyde or keto group in regard of these monosaccharides. D-Ribose, the portion of RNA in carbohydrates, is a five-carbon aldose. Six-carbon aldoses are found in D-glucose, D-manose, and D-galactose. It may be noted that D-glucose and D-mannose differ in configuration only at C-2. Sugars differing in configuration at a single asymmetric center are called epimers. Thus, D-glucose and D-mannose are epimeric at C-2; D-glucose and D-galactose are epimers at C-4.
B-Disaccharides
A disaccharides formed through linkage of two monosaccharides joined by glycosidic bond,this linkage may be (alpha) or (beta). Three most abundant disaccharides are sucrose, lactose, and maltose. In sucrose there is linkage between glucose unit and a fructose unit, Lactose, the major sugr in milk, composed of galactose linked to glucose, In maltose, there is a linkage joins two glucose units. Disaccharides can be homo-saccharides(ex: maltose) and hetero-disaccharides(ex:sucrose and lactose).they are hydrolysed by mineral acids to a simpler sugars,each of naturally occurring disaccharides is hydrolysed by its own specific enzymes.
C-Oligosaccharide
An oligosaccharide is a saccharide polymer formed of small number (typically two to ten) ,can be hydrolysed to a simpler carbohydrates. and is also known as simple sugars. The oligosaccharides are glycosides in which the monosaccharide units are linked through C-1 one unit and hydroxyl group at any position on the other unit.
D-Polysaccharides
Polysaccharides are complex carbohydrates formed of more than Ten units of monosaccharides,and can be hydrolysed to simpler carbohydrates . They are polymers composed of many monosaccharides bound together by glycosidic bonds. They are very large, often branched, macromolecules.They may be amorphous, insoluble in water, and have no sweet taste.When all the monosaccharides in a polysaccharide chain are of the same type, the polysaccharide is named a homo-polysaccharide and when more than one type of monosaccharides is found, they are named hetero-polysaccharides.Polysaccharides have a general formula of Cx(H2O)y where(x)can be any number between 200 and 2500,the general formula can also be represented as (C6H10O5)n where n={40...3000}.
Carbohydrates being the Next level in Pharmaceutical Research
Synthetic carbohydrates are used to study their functions in important biological processes such as inflammation, identification of cells, immunological response, and fertilization. The development of an automated oligosaccharide synthesizer significantly accelerates the modification of complex, naturally occurring carbohydrates as well as chemical-modified oligosaccharide structures, and guarantees to have major influence on the field of glycobiology. Tools such as microarrays, resonance spectroscopy of surface plasmon, and conjugates of fluorescent carbohydrates have shown to plan carbohydrate interactions in biological systems.Carbohydrate trials as active agents, such as fully synthetic oligosaccharide vaccines for the treatment of tropical diseases (e.g. malaria), bacterial infections (e.g. tuberculosis), viral infections such as
HIV, and cancer. Aminoglycosides serve as examples of drugs that operate by interactions between carbohydrates – nucleic-acids, while heparin managed by interactions between carbohydrates – proteins.
Determination of carbohydrates in biomass
Introduction : This technique is suitable for experiments not including extractives. This technique utilizes a two-step acid hydrolysis to break the biomass into more readily observable forms. It is also possible to combine ash and protein into the acid-insoluble material that must be accounted for during gravimetric investigation. During hydrolysis, the polymeric carbohydrates are hydrolyzed into the monomeric forms which are solvent in the fluid for hydrolysis. Then, HPLC is used to test them. Protein will split into fluid division too.
Carbohydrate Conjugates to Vaccine Improvement
Antibodies are effective tools effective of enacting the immune structure for assuring against various diseases.As carbohydrates can play critical parts in immune recognition,they have been widely connected in the advancement of immunization .Carbohydrate antigens were studied in different pathogenic species and cancer vaccination.Polysaccharides such as dextran and β-glucan can serve as intelligent vaccine carriers for successful transmission of antigens to immune cells.Many glycolipids, such as galactosylceramide and monophosphoryl lipid A, are potent immune stimulators that have been recognized as adjuvants to the antibody.
Monitoring for antibodies which bind carbohydrate epitopes of tumor-associated antigens:
Cells that produce antibodies that bind carbohydrate epitopes of glycoproteins are distinguished by screening in raw, or preferably partially decontaminated, form with mucinous body liquids. Fine differences in antibody specificity can be detected by further screening with mucinous body liquids treated to modify the value of the carbohydrate epitope, e.g. sialic acid expulsion from a sialosyl Lewis-a epitope. The antibodies chosen can be used in immunopurification, immunodiagnosis, and immunotherapy. Antibodies whose binding to carbohydrate epitopes such as sialosyl Lewis-a is relatively insensitive to pH have been identified via that strategy. Such antibodies are of specific value in immunological strategies where pH may be a consideration.
Monoclonal antibodies represent the most efficient class of biopharmaceuticals for cancer treatment. Therapeutic antibodies 'activity mechanisms are extremely different and reflect their ability to engage in antibody-dependent effector mechanisms, internalize to deliver cytotoxic payloads, and have direct impacts on cells via lysis or by modulating their target antigens' biological pathways. Critically, glycosylation is one of the fundamental changes in cancer, and carbohydrate-binding antibodies may be formed to precisely identify tumor cells over ordinary tissues. A promising category of cell surface antibody targets contains carbohydrates that are seen as glycolipids or glycoproteins.
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