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.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with cell metabolism
Protein critical for insulin secretion may be contributor to diabetes
Oct 26, 2009 |
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A cellular protein from a family involved in several human diseases is crucial for the proper production and release of insulin, new research has found, suggesting that the protein might play a role in diabetes.
Study Shows How Normal Cells Influence Tumor Growth
Oct 21, 2009 |
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(PhysOrg.com) -- It was once thought that the two communities of cells within a cancerous breast tumor - fast-growing malignant cells and the normal cells that surround them - existed independently, without interaction. Then ...
Could antioxidants make us more, not less, prone to diabetes? Study says yes
Oct 06, 2009 |
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We've all heard about the damage that reactive oxygen species (ROS) - aka free radicals - can do to our bodies and the sales pitches for antioxidant vitamins, skin creams or "superfoods" that can stop them. In fact, there ...
Dynamic changes in DNA linked to human diabetes
Sep 01, 2009 |
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A study in the September issue of Cell Metabolism, a Cell Press publication, may give new meaning to the adage, "You are what you eat."
Unstable proteins can cause premature ageing
Aug 06, 2009 |
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(PhysOrg.com) -- The normal ageing process has long been linked to problems with cell respiration, the process through which the cells extract energy from nutrients. Researchers at the Swedish medical university Karolinska ...
Gut hormone has 'remote control' on blood sugar
Aug 05, 2009 |
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A gut hormone first described in 1928 plays an unanticipated and important role in the remote control of blood sugar production in the liver, according to a report in the August 6th Cell Metabolism, a Cell Press publication. What's ...
Link between obesity and diabetes discovered
Jul 08, 2009 |
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A Monash University study has proven a critical link between obesity and the onset of Type 2 diabetes, a discovery which could lead to the design of a drug to prevent the disease.
Researchers show new antioxidant could help treat cardiovascular disease
Jun 29, 2009 |
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(PhysOrg.com) -- Researchers at the University of Glasgow believe they have found a potential new treatment for cardiovascular disease which reduces blood pressure.
Researchers discover pathway with implications for obesity
Jun 03, 2009 |
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(PhysOrg.com) -- Cornell scientists have discovered how two related proteins and their roles in a key molecular pathway are critical to creating obesity-causing fat cells.
Key protein in cellular respiration discovered
Apr 08, 2009 |
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Many diseases derive from problems with cellular respiration, the process through which cells extract energy from nutrients. Researchers at the Swedish medical university Karolinska Institutet have now discovered a new function ...
High-fat diets plus extra protein make for bad mix
Apr 07, 2009 |
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It's basically a given that diets loaded with fat can lead to considerable health problems. But a new study in the April issue of Cell Metabolism, a Cell Press publication, shows that in some cases diets that are high in bot ...
Scientists reveal mechanism that regulates cancer-causing gene
Mar 26, 2009 |
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Two University of Rhode Island scientists have revealed how a cancer causing protein is regulated by reactive oxygen species (ROS) -- a type of stress signal. Their findings provide new insight into how this protein normally ...
Drugs that act on 'fasting signal' may curb insulin resistance in obese
Mar 03, 2009 |
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A report in the March issue of Cell Metabolism, a Cell Press publication, has found that a signal known to play a role during fasting also switches on early in the fat tissue of obese mice as they progress toward type 2 diab ...
New clues to pancreatic cells' destruction in diabetes
Biology /
Feb 03, 2009 |
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Researchers have found what appears to be a major culprit behind the loss of insulin-producing β cells from the pancreases of people with diabetes, a critical event in the progression of the disease.
Fat-free diet reduces liver fat in fat-free mice
Biology /
Feb 03, 2009 |
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Researchers at UT Southwestern Medical Center have uncovered crucial clues about a paradoxical disease in which patients with no body fat develop many of the health complications usually found in obese people.
