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Tom Cech Interview - Can you explain what the RNA world is?

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When scientists in the past have tried to think about what would be the simplest... ...self-reproducing system, a primitive start to Life, they said: Well, this is a tough problem, because in order to have one generation... ...provide the information to allow the next generation, which is very fundamental to Life, you have to have some kind of reproduction, you have to have offspring which can carry on the life form to the next generation, you need to have some kind of informational molecule... ...and in our cells that’s DNA, the double helix that makes up the genes. But then, DNA by itself can’t do anything. Even just to copy it into daughter molecules of DNA, from the mother molecule, you need to have DNA polymerase, which is a very sophisticated protein enzyme. So the people who were theorizing about the origins of life... ...were sort of stuck, because they said: It just seems very improbable that by random chemical processes... ...in some small drop of liquid, you would get an informational molecule... ...and a protein that could reproduce that informational molecule. DNA and a protein, by just random chemistry – seems unlikely. Now that we know that RNA can be both an informational molecule and a biocatalyst, and in fact it can do this sort of reaction of replicating, of taking one molecule and... ...making another identical molecule to it, then maybe at the very beginning there was an RNA world. No DNA, no proteins, just RNA replicating itself. And then, as time went on, the RNA could catalyze the assembly of amino acids to make the proteins... ...and now you can do a much wider range of biological catalysis. DNA is thought now to be a very recent invention. It’s not even that important. Simple systems, viruses for example, have RNA and protein - - many viruses don’t even have any DNA. They just use RNA as their informational molecule. So DNA is now thought of as being a relatively recent invention in Evolution, that allows larger genomes to be stable and it protects the genetic information.

Video Details

Duration: 2 minutes and 58 seconds
Country: Sweden
Language: English
Producer: MoleClues TV
Director: Per Thoren
Views: 326
Posted by: locumele on Sep 24, 2009

Nobel Prize winner Tom Cech interviewed for MoleClues.org

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