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Vil man fra en aminosyresekvens konstruere det tilhørende RNA eller DNA er Skal man aflæse en DNA-kode, er tabellen s i Det Levendes Kemi bedst. Her siges det, at faget er en blanding af Biologi B og Kemi B. Faget fokuserer på anvendes biologiske systemer, levende organismer, eller afledninger deraf. retninger; således fordybede han sig grundig i kemi ved Den polytekniske Læreanstalt. Det blev dog fornemmelig Paris, der fængslede ham. Han måtte bort fra det døde og til det levende, fra teori til praksis, og dette lykkedes ham, da .

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So we’re now in this time period right over here.

And I’m not a Greek scholar. So this oxygen production, it’s crucial, one, to having an ozone layer so that eventually life can exist on the land. But this, as far as I can tell, is our best current understanding. And so the whole– as the theory goes– the whole Earth essentially just iced over. And we said in the last video that they were producing oxygen, but most of that oxygen was being absorbed by iron in the oceans.

And “arche” comes from ancient Greek. The first is is that it became suitable now for eukaryotes to exist. Eukaryotic organisms, remember, these are organisms that have nuclear membranes around their DNA.

It means beginning llevendes origin. And we are eukaryotes. But what happens is we enter into the Proterozoic Eon. It’s a greenhouse ,emi. It’s possible that maybe life first started to exist at the end of the Hadeon Eon. It’s the first time that eukaryotes can now come into existence because they now have oxygen to, I guess we could say, breathe. It’s poisonous to most of the other organisms on the planet that were krmi, that did not need oxygen, that actually found oxygen poisonous.


And now that oxygen began to accumulate, we have the Oxygen Catastrophe. I mean the current theory is that mitochondria is actually descended from kind of an ancient prokaryotic cell, an ancient bacteria. And methane is an ozone– not an ozone.

But it’s even more violet than purple. And once it saturates, it starts to get released into the atmosphere. They marked it this right here, 2.

So this right over here, 2. So any of you Greeks out there, forgive me if I’m not getting the translation exactly right.

Ozonlaget og eukaryoter dukker op i æonen Proterozoikum (video) | Khan Academy

We actually talk about respiration that occurs in the mitochondria. There’s some evidence it might have been a little earlier, some evidence it might have a little later. But this is the current understanding of when things happened.

And Proterozoic Eon, it’s right over here. And once it reacts with the oxygen and starts dropping out of the atmosphere as methane, we believe the Earth cooled down. So it’s constantly being bombarded by with ultraviolet radiation from the Sun, which is very inhospitable to DNA and to life.

I’m sure that number will be refined. For at logge ind og bruge alle funktionerne i Khan Academy, skal du aktivere JavaScript i din browser. But it becomes oxygen rich enough that at least the environment becomes suitable for eurkaryotic organisms keni eukaryotic cells.

Video udskrift We left off in the last video in the Archean Eon.


Ozonlaget og eukaryoter dukker op i æonen Proterozoikum

Now, the third thing that happened, and this is also pretty significant event, we believe that that oxygen that started to accumulate in the atmosphere, reacted with methane in the atmosphere. It’s sometimes called the Huronic glaciation. Oversigt over menneskets evolution. So as we go through the Proterozoic Eon, I guess the big markers of it is it’s the first time levenddes we now have an oxygen-rich atmosphere.

Organisk kemi by charlotte Rosenvinge on Prezi

I can only imagine that 50 years from now, or years from now, if someone is still watching this video, a lot of this might say, hey, we found out later that oxygen started to accumulate in the atmosphere earlier or later or that eukaryotes occurred earlier or later. So we are able to find rocks that we can date to be roughly 3. It helps retain heat in the atmosphere. And the other big thing is now this is where the ozone forms.


And maybe we’ll look at the geological record, or the fossil record, and we’ll move these things around in the vet. So what happened, and what I guess has to happen, and the reason why we are able to live on land now is that we have an ozone layer.

Now, the other interesting thing that happened– remember, we’re being bombarded with UV radiation from the Sun.