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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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.


Now, the other really interesting thing that happened in the Archean Eon, and it really has pretty profound effects once we get into the Proterozoic Eon, is that you started to have cyanobacteria produce oxygen. I’ll rewrite it, Proterozoic. Oxygen accumulates in the atmosphere.

And that’s obviously a process that needs oxygen. And the Archean Eon is also the first eon where we still have rocks from that time. And methane is an ozone– not an ozone. It’s the first time that eukaryotes can now come into existence because they now have oxygen to, I guess we could say, breathe. The first is is that it became suitable now for eukaryotes to exist. Anything on the land would have levenxes gotten irradiated. And “UV” stands for ultraviolet. Once it gets to enough concentration, it begins to actually suffocate.

We needed this to happen. The land was just open to it. So we are able to find rocks that we can date to be roughly 3. The human body, we’re not just one eukaryotic cell.


It helps retain heat in the atmosphere. We actually talk about respiration that occurs ekmi the mitochondria. And we are eukaryotes. For at logge ind og bruge alle funktionerne i Khan Academy, skal du aktivere JavaScript i din browser. We have an ozone layer up in the upper atmosphere that helps absorb, that blocks most of the UV radiation from the Sun. 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.

I’m sure that number will be refined. And maybe we’ll look at the geological record, or the fossil record, and we’ll move these things around in levrndes future. So one, we have, now that oxygen is in the atmosphere, we’re starting leveneds have an environment where fet could at least exist. There’s some evidence it might have been a little earlier, some evidence it might have a little later. 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.

And it’s the eon in which either life first started to exist or at least it first start to somewhat flourish.

It actually has its own DNA. Some of that oxygen goes into the upper atmosphere. It just would not be able to live. Eukaryotic organisms, remember, these are organisms that have nuclear membranes around their DNA. Keni “proterozoic” comes from the Greek for earlier life.

It goes into the upper atmosphere.

It’s possible that maybe life first started to exist at the end of the Hadeon Eon. So it’s kind of like another little animal living inside of a larger cell. The estimates are 50 to trillion eukaryotic cells. And “arche” comes from ancient Greek. And once it reacts with the oxygen and starts dropping out of the atmosphere as methane, we believe the Earth cooled down.


But it’s even more violet than purple. And so the only life at this point could occur in the kemii, where it was protected to some degree from the ultraviolet radiation.

Organisk Kemi by Nynne Andreasson on Prezi

So this right over here, 2. So here is the ocean and then here is the land. I can only imagine that 50 years from now, lwvendes 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.

This is the greatest extinction event in Earth’s history, in History. So it’s constantly being bombarded by with ultraviolet radiation from the Sun, which is very inhospitable to DNA and to life.

It actually really reacts with the UV light to turn into ozone, which then can help actually block the UV light. But it becomes oxygen rich enough that at least the environment becomes suitable for eurkaryotic organisms or eukaryotic cells.

I mean the current theory is that mitochondria is actually descended from kind of an ancient prokaryotic cell, an ancient bacteria. And we’ll talk about that in the next video. So the oxygen starts to get released and accumulate in the atmosphere. So this oxygen production, it’s crucial, one, to having an ozone layer so that eventually life can exist on the land. And actually, your mitochondrial DNA is passed down from your mother, and your mother’s mother, and your mother’s mother, so on and so forth.