quagmire02
All American
44225 Posts
user info
edit post |
http://arstechnica.com/science/2012/11/remodeled-enzyme-converts-carbon-dioxide-into-methane/
| Quote : | "An engineered enzyme is the first single biological catalyst that converts carbon dioxide into a renewable form of energy: methane. Surprisingly, the same enzyme can use carbon dioxide to make an important ingredient in plastics as well.
Recycling carbon dioxide by turning it into fuels like methanol (CH3OH) or methane (CH4) might be one way to slow the CO2 accumulation in our atmosphere. But that's quite a challenge, because CO2 is a pretty inert molecule and doesn't readily participate in chemical reactions. So chemists have developed metal-containing catalysts to assist in the reduction reactions that convert it to methane and other carbon-containing small molecules. Alternatively, bacteria can use CO2 to make methane, but they use a series of proteins to catalyze the transformation.
Lance Seefeldt at Utah State University and his colleagues study a bacterial enzyme called a nitrogenase, which reduces nitrogen gas (N2) to ammonia (NH3) with the help of a cluster of iron and molybdenum atoms buried inside the protein. The reduction of carbon dioxide to methane requires a transfer of eight electrons, just as ammonia production does, so the scientists wondered if an altered version of this enzyme could accept and reduce carbon dioxide.
They changed two amino acids in one subunit of this protein. The altered nitrogenase converts carbon dioxide to methane for 20 minutes and then slows down. The enzyme’s reaction rate and the number of reactions it catalyzes are comparable to similar soluble metal catalysts.
But the real surprise to Seefeldt was that the enzyme triggered a more complex reaction: it combined two molecules, carbon dioxide and acetylene, to form propylene, a three-carbon ingredient in many plastics. That particular reaction is new for any catalyst, inorganic or biological, he says.
The scientists want to test other versions of the enzyme to see if it can use CO2 to build other kinds of molecules, too. Enzymes are used as biocatalysts to make some chemicals on an industrial scale, but that’s not Seefeldt’s ultimate goal in engineering this enzyme. He wants to extend this enzyme’s catalytic ability to better understand how the protein works.
Lessons about how the binding site environment helps catalyze a particular reaction might translate into clues that help other scientists build better catalysts for the production of methane and other commercially relevant chemicals. This altered enzyme won’t solve our carbon dioxide or energy problems on its own. But its structure, or that of its yet-to-be-found mutant cousins, might provide some useful hints that do help us address those issues by recycling CO2 through chemistry." |
i'm not serious, but i thought it was neat 11/16/2012 2:06:51 PM
|
Sweden
All American
12288 Posts
user info
edit post |
further reading on the issue:
| Quote : | " NEW YORK - A man was charged with withdrawing $2 million from an account after a bank confused him with a man who has the same name.
ADVERTISEMENT
Benjamin Lovell was arraigned Tuesday on grand larceny charges. The 48-year-old salesman said he tried to tell officials at Commerce Bank in December that he did not have a $5 million account. He says he was told it was his and he could withdraw the money.
Prosecutors said the bank — which advertises itself as America's Most Convenient Bank — confused Lovell with a Benjamin Lovell who works for a property management company.
The lesser-funded Lovell gave away some of the withdrawn money and blew some of it on gifts, but lost much of it on bad investments, prosecutors said.
The district attorney's office did not immediately have information on his lawyer. Calls left with" |
11/16/2012 2:15:53 PM |
