Carbohydrate
hideCarbohydrates [α] or saccharides[β] are the most abundant of the four major classes of biomolecules. They fill numerous roles in living things, such as the storage and transport of energy (e.g., starch, glycogen) and structural components (e.g., cellulose in plants and chitin in animals). In addition, carbohydrates and their derivatives play major roles in the working process of the immune system, fertilization, pathogenesis, blood clotting, and development.
Carbohydrates make up most of the organic matter on Earth because of their extensive roles in all forms of life. First, carbohydrates serve as energy stores, fuels, and metabolic intermediates. Second, ribose and deoxyribose sugars form part of the structural framework of RNA and DNA. Third, polysaccharides are structural elements in the cell walls of bacteria and plants. In fact, cellulose, the main constituent of plant cell walls, is one of the most abundant organic compounds in the biosphere. Fourth, carbohydrates are linked to many proteins and lipids, where they play key roles in mediating interactions between cells and interactions between cells and other elements in the cellular environment.
Carbohydrates are simple organic compounds that are aldehydes or ketones with many hydroxyl groups added, usually one on each carbon atom that is not part of the aldehyde or ketone functional group. The basic carbohydrate units are called monosaccharides; examples are glucose, galactose, and fructose. The general stoichiometric formula of an unmodified monosaccharide is (C·H2O)n, where n is any number of three or greater; however, not all carbohydrates conform to this precise stoichiometric definition (e.g., uronic acids, deoxy-sugars such as fucose), nor are all chemicals that do conform to this definition automatically classified as carbohydrates.
Monosaccharides can be linked together into what are called polysaccharides (or oligosaccharides) in a large variety of ways. Many carbohydrates contain one or more modified monosaccharide units that have had one or more groups replaced or removed. For example, deoxyribose, a component of DNA, is a modified version of ribose; chitin is composed of repeating units of N-acetylglucosamine, a nitrogen-containing form of glucose.
While the scientific nomenclature of carbohydrates is complex, the names of carbohydrates very often end in the suffix -ose. Glycoinformatics is the specialised field of study that deals with the specific and unique bioinformatics of carbohydrates.
For more information about Carbohydrate, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with carbohydrate
Study identifies genetic predeterminants for diabetes in African-Americans
Dec 09, 2009 |
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For years, scientists have tried to determine the basis for discrepancies between race and the predisposition for development of diseases such as type II diabetes and cardiovascular disease. Could factors ...
Mood improves on low-fat, but not low-carb, diet plan
Nov 09, 2009 |
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After one year, a low-calorie, low-fat diet appears more beneficial to dieters' mood than a low-carbohydrate plan with the same number of calories, according to a report in the November 9 issue of Archives of Internal Me ...
Alzheimer's researchers find high protein diet shrinks brain
Medicine & Health / Neuroscience
Oct 20, 2009 |
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One of the many reasons to pick a low-calorie, low-fat diet rich in vegetables, fruits, and fish is that a host of epidemiological studies have suggested that such a diet may delay the onset or slow the progression of Alzheimer's ...
Genome sequence published for important biofuels yeast
Oct 06, 2009 |
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(PhysOrg.com) -- A strain of yeast that thrives on turning sugar cane into ethanol for biofuel has had its genome completely sequenced by researchers at Duke University Medical Center.
Low-carb diets linked to atherosclerosis and impaired blood vessel growth
Aug 24, 2009 |
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(PhysOrg.com) -- Even as low-carbohydrate/high-protein diets have proven successful at helping individuals rapidly lose weight, little is known about the diets' long-term effects on vascular health.
Flexible neck in cell-receptor DC-SIGN targets more pathogens
Jul 14, 2009 |
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Pathogen recognition is the foundation of the body's immune response and survival against infection. A small cell-receptor protein called DC-SIGN is part of the immune system, and recognizes certain pathogens, including those ...
Diets bad for teeth are also bad for the body
Jul 09, 2009 |
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(PhysOrg.com) -- Dental disease may be a wake-up call that your diet is harming your body.
Ozone depletes oil seed rape productivity
Jun 29, 2009 |
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With rising ozone levels scientists have found that high ozone conditions cause a 30 percent decrease in yield and an increase in the concentration of a group of compounds with toxic effects to livestock, but anticarcinogenic ...
Carb synthesis sheds light on promising tuberculosis drug target
Jun 22, 2009 |
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A fundamental question about how sugar units are strung together into long carbohydrate chains has also pinpointed a promising way to target new medicines against tuberculosis.
Moderately Reduced Carbohydrate Diet Keeps People Feeling Full Longer
Jun 11, 2009 |
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A modest reduction in the amount of carbohydrates eaten, without calorie restriction and weight loss, appears to increase a sense of fullness, which may help people eat less, a preliminary study found.
Carbohydrate restriction may slow prostate tumor growth
May 26, 2009 |
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Restricting carbohydrates, regardless of weight loss, appears to slow the growth of prostate tumors, according to an animal study being published this week by researchers in the Duke Prostate Center.
Revealing the long-awaited atomic structure of a well-known enzyme
May 20, 2009 |
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A Boston University-led research team has identified the structural underpinnings of a widely-known enzyme -- acetoacetate decarboxylase (AADase) -- that was first described correctly more than 43 years ago including how ...
Calorie restriction causes temporal changes in liver metabolism
May 04, 2009 |
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Moderate calorie restriction causes temporal changes in the liver and skeletal muscle metabolism, whereas moderate weight loss affects muscle, according to a new study in Gastroenterology, the official journal of the Americ ...
Chewing gum reduces snack cravings and decreases consumption of sweet snacks
Apr 19, 2009 |
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Men and women who chewed Extra® sugar-free gum three times hourly in the afternoon chose and consumed less snacks and specifically, less sweet snacks than they did when they did not chew gum. They still reached for a variety ...
Energy drinks work -- in mysterious ways
Apr 15, 2009 |
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Runners clutching bottles of energy drink are a common sight, and it has long been known that sugary drinks and sweets can significantly improve athletes' performance in endurance events. The question is how?
