Metabolism
hideMetabolism is the set of chemical reactions that occur in living organisms to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories. Catabolism breaks down organic matter, for example to harvest energy in cellular respiration. Anabolism, on the other hand, uses energy to construct components of cells such as proteins and nucleic acids.
The chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is transformed into another by a sequence of enzymes. Enzymes are crucial to metabolism because they allow organisms to drive desirable but thermodynamically unfavorable reactions by coupling them to favorable ones, and because they act as catalysts to allow these reactions to proceed quickly and efficiently. Enzymes also allow the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells.
The metabolism of an organism determines which substances it will find nutritious and which it will find poisonous. For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals. The speed of metabolism, the metabolic rate, also influences how much food an organism will require.
A striking feature of metabolism is the similarity of the basic metabolic pathways between even vastly different species. For example, the set of carboxylic acids that are best known as the intermediates in the citric acid cycle are present in all organisms, being found in species as diverse as the unicellular bacteria Escherichia coli and huge multicellular organisms like elephants. These striking similarities in metabolism are most likely the result of the high efficiency of these pathways, and of their early appearance in evolutionary history.
For more information about Metabolism, read the full article at
Wikipedia.
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News tagged with metabolism
Research sheds light on workings of anti-cancer drug
Chemistry / Analytical Chemistry
Nov 26, 2009 |
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(PhysOrg.com) -- The copper sequestering drug tetrathiomolybdate (TM) has been shown in studies to be effective in the treatment of Wilson disease, a disease caused by an overload of copper, and certain metastatic cancers. ...
Upending textbook science on Alzheimer's disease
Medicine & Health / Neuroscience
Nov 23, 2009 |
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Alzheimer's disease is caused by the build-up of a brain peptide called amyloid-beta. That's why eliminating the protein has been the focus of almost all drug research pursuing a cure for the devastating neurodegenerative ...
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Nov 27, 2009 |
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It doesn't seem like a fair fight. In one corner loomed the Thanksgiving table, groaning with poultry, pie and mashed potatoes.
Molecule discovered that makes obese people develop diabetes
Nov 24, 2009 |
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Many people who are overweight or obese develop insulin resistance and type 2 diabetes at some stage in their lives. A European research team has now discovered that obese people have large amounts of the ...
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Feeding the clock: Cycles of feeding and fasting drive circadian gene expression in the liver
Nov 25, 2009 |
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When you eat may be just as vital to your health as what you eat, found researchers at the Salk Institute for Biological Studies. Their experiments in mice revealed that the daily waxing and waning of thousands ...
Does a placebo gene exist?
1hour ago |
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A short time ago, Swedish scientists published a paper suggesting the existence of a genetic disposition to respond to placebo, thus giving rise to debate in the media about a possible "placebo gene." In the current issue ...
Systems biology approach provides insulin resistance insights
Nov 23, 2009 |
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Researchers from the University of California, San Diego recently offered the sharpest-yet picture of how core biochemical pathways in skeletal muscle cells and fat cells are altered in people who suffer from ...
Metobolomics uncovers key indicators of nonalcoholic fatty liver disease
Nov 24, 2009 |
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A recent metobolomics study by researchers from Virginia Commonwealth University Medical Center in Richmond found that impaired peroxisomal oxidation of polyunsaturated fatty acids (PUFA) is associated with the progression ...
First-ever blueprint of a minimal cell is more complex than expected
Nov 26, 2009 |
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What are the bare essentials of life, the indispensable ingredients required to produce a cell that can survive on its own? Can we describe the molecular anatomy of a cell, and understand how an entire organism ...
America's increasing food waste is laying waste to the environment
Nov 25, 2009 |
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Food waste contributes to excess consumption of freshwater and fossil fuels which, along with methane and carbon dioxide emissions from decomposing food, impacts global climate change. In a new paper published in the open-access, ...
Scientists discover soy component may be key to fighting colon cancer
Nov 24, 2009 |
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A study conducted by Children's Hospital & Research Center Oakland scientists identifies a new class of therapeutic agents found naturally in soy that can prevent and possibly treat colon cancer, the third most deadly form ...
A RANK insider resolving the enigma of the fever chart
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Mammals have evolved a complex system for controlling bone remodeling. Babies require calcium for healthy bones and they obtain it from their mother's milk. Nursing mothers release calcium from their bones. Surprisingly, ...
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