Related topics: obesity
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 metabolism
Extinct goat was cold-blooded
Nov 18, 2009 |
4.9 / 5 (39) |
11
(PhysOrg.com) -- An extinct goat that lived on a barren Mediterranean island survived for millions of years by reducing in size and by becoming cold-blooded, which has never before been discovered in mammals.
Scientists pinpoint origin of dissolved arsenic in Bangladesh drinking water
Nov 15, 2009 |
4.8 / 5 (21) |
1
Researchers in MIT's Department of Civil and Environmental Engineering believe they have pinpointed a pathway by which arsenic may be contaminating the drinking water in Bangladesh, a phenomenon that has puzzled ...
Warm-blooded dinosaurs worked up a sweat
Nov 11, 2009 |
5 / 5 (5) |
1
(PhysOrg.com) -- Were dinosaurs endothermic (warm-blooded) like present-day mammals and birds or ectothermic (cold-blooded) like present-day lizards? The implications of this simple-sounding question go beyond ...
How cigarettes calm you down
Apr 24, 2009 |
4.8 / 5 (9) |
0
The calming neurological effects of nicotine have been demonstrated in a group of non-smokers during anger provocation. Researchers writing in BioMed Central's open access journal Behavioral and Brain Functions suggest that n ...
Disabling enzyme allows mice to gorge without becoming obese, new study finds
Jan 11, 2009 |
5 / 5 (13) |
1
Researchers at the University of California, Berkeley, have identified a new enzyme that plays a far more important role than expected in controlling the breakdown of fat. In a new study to be published Jan. 11 in the journal ...
Study shows how gene action may lead to diabetes prevention, cure
Dec 11, 2009 |
4.3 / 5 (7) |
2
A gene commonly studied by cancer researchers has been linked to the metabolic inflammation that leads to diabetes.
Dessert on your mind? Your muscles may be getting the message
Dec 01, 2009 |
5 / 5 (1) |
0
Even the anticipation of sweets may cause our muscles to start taking up more blood sugar, say researchers reporting in the December issue of Cell Metabolism. That message is delivered via neurons in the brain's hypothalamus contai ...
Western diets turn on fat genes
Nov 30, 2009 |
4.7 / 5 (7) |
3
Those extra helpings of gravy and dessert at the holiday table are even less of a help to your waistline than previously thought. According to a new research report recently appearing online in The FASEB Journal, a diet t ...
Research sheds light on workings of anti-cancer drug
Chemistry / Analytical Chemistry
Nov 26, 2009 |
5 / 5 (1) |
0
(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 |
5 / 5 (6) |
0
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 ...
Protein critical for insulin secretion may be contributor to diabetes
Oct 26, 2009 |
not rated yet |
0
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 |
5 / 5 (1) |
1
(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 |
2.7 / 5 (10) |
0
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 ...
'Promiscuous' protein interactions found in the nuclear pore complex
Sep 29, 2009 |
5 / 5 (1) |
0
(PhysOrg.com) -- The NPC is the only way in or out of a cell's nucleus. It plays a key role in cellular metabolism and signaling, and any malfunction in these pores can have lethal consequences. Now new research reveals further ...
Exotic life beyond Earth? Looking for life as we don't know it
Space & Earth / Space Exploration
Sep 18, 2009 |
4.8 / 5 (24) |
8
Scientists at a new interdisciplinary research institute in Austria are working to uncover how life might evolve with "exotic" biochemistry and solvents, such as sulphuric acid instead of water. Their research ...
