Mitochondria produce adenosine triphosphate (ATP), commonly called the universal energy currency of the body.
The driver for this process is an electrochemical membrane potential, which is created by a series of proton pumps - positive charges and negative ones. These complex, macromolecular machines are collectively known as the respiratory chain.
The structure of the largest protein complex in the respiratory chain, that of mitochondrial complex I, has been examined by scientists from the Frankfurt "Macromolecular Complexes" cluster of excellence, working together with the University of Freiburg, by X-ray diffraction analysis.

Wise advice.
Julia Wolf,
CC BY-NC-SABy Arun Vishwanath, University at Buffalo, The State University of New York
What exactly is cometary globule CG4?
That's still a bit of a mystery. Despite the name, it has nothing to do with comets. In 1976, several elongated comet-like objects were discovered in pictures taken with the UK Schmidt Telescope in Australia. Because of their appearance, and despite any connection with comets, they became known as cometary globules. They were all located in a huge patch of glowing gas called the Gum Nebula. They had dense, dark, dusty heads and long, faint tails, which were generally pointing away from the Vela supernova remnant located at the center of the Gum Nebula. Although these objects are relatively close by, it took astronomers a long time to find them as they glow very dimly and are therefore hard to detect.
As predators go, cone snails are slow-moving and lack the typical fighting parts. They've made up for it by producing a vast array of fast-acting toxins that target the nervous systems of prey. A new study reveals that some cone snails add a weaponized form of insulin to the venom cocktail they use to disable fish.
"It is very unlikely that it is serving a different purpose," said lead author Helena Safavi-Hemami, a research assistant professor at the University of Utah.
"This is a unique type of insulin. It is shorter than any insulin that has been described in any animal," said senior author Baldomero M. Olivera, a distinguished professor of biology at the University of Utah. "We found it in the venom in large amounts."
Recent research has linked autism with a lack of "pruning" in developing brain connections, but a new Dartmouth study suggests instead it is the excessive growth of new connections that causes sensory overload in people with the disorder.
The results, which have broad implications for understanding the neurobiological basis of autism spectrum disorders, appear in The Journal of Neuroscience. A PDF of the study is available on request.
Every business wants to capitalize on imagination and innovation - but a corporate structure may be the wrong way to promote it. And if you really want to kill creativity, have social authoritarians in government controlling your culture.
Collectivism is bad for the imagination. It's hard to think about art when you have to think about the good of the state, according to a paper in the Journal of Business Research, which compared nearly 300 individuals from Taiwan, a collectivist society, and Canada, slightly more individualistic.
Scientists may be on the way to genetically modifying plants to naturally protect against pests in new ways. That is good news for people in developing nations and fans of the environment. Older insecticides present environmental and health risks and insects develop resistance to them, complicating pest-control strategies.
Along with that, millions of deaths result from diseases transmitted by insects each year, not to mention economic losses totaling billions of dollars annually.
In 1722, when Europeans arrived on Easter Island, nearly 2,300 miles off the west coast of Chile, the native Polynesian culture known as Rapa Nui were already in a demographic tailspin from which they would not recover.
Pick a fad belief of the moment, and someone has correlated it to Easter Island. Environmental damage? Easter Island. Climate change? Easter Island. Add in political partisanship and lifestyle diseases and you can also find a correlation-causation arrow being abused.
Will there ever be an answer? Hard to say, but a new paper attempts at least some clarification.
Throughout the 20th century, medical research and public health science was primarily done by corporations - the United States, with 5 percent of the population, generated more than 50 percent of the money and a whole lot more of the science.
No more. Medical research has declined in the United States. It's a win for multiculturalism and a win for globalization but a loss for the U.S. Yet we have no one else to blame. We are not being out-competed by China when it comes to science, we are losing medical research because we have been taught to hate drug companies and that new drugs should be cheap. That has had substantial impact on our policy.
Coating the mouth with foods stored in containers that used bisphenol A
(BPA), like soup, does not lead to high levels of BPA in blood.
BPA is used to make some plastics and to seal canned food containers against bacterial contamination. Food which picks up trace amounts of BPA from packaging is the major source of human exposure, according to environmental critics, and the health concerns about BPA center on potential to mimic certain hormones at really high exposures.