in this video, we're gonna be talking about something pretty interesting how life first began on Earth, and so a B O Genesis is the natural process of the origin of life on Earth, and it describes how life first formed from non living simple molecules. And the theory suggests that life originated in the oceans of Earth about 3.8 billion years ago, and this is billion with a B. So we're talking about an incredibly long time ago, and the theory suggests that life arose from non biological materials, and these non biological materials are also known as prebiotic materials or just pre biotics. And these probiotics were in high abundance on early Earth and include molecules such as hydrogen gas, water, ammonia, carbon dioxide and methane. And so the question is, how did these probiotics, or these non biological molecules convert into the very first biomolecules? And so there are a few different theories. The atmosphere conversion theories suggest that the sun and lightning converted the pre biotics into the first simple biomolecules, and the hydrothermal vents theory suggest that the first bio molecules were formed in areas where the sunlight and lightning could not penetrate and that the vents on the ocean floors were the ones toe provide the energy to convert the pre biotics into the first bio molecule monomers. And so let's take a look at our example to clear this up. And in this example of the bio molecule monitor information on the left. Over here, what we have are the prebiotic materials or the non biological materials. And so the first theory suggests that solar radiation and lightning provided the energy to spark the pre biotics to convert into the first bio molecule monomers. And, uh, the second theory theory to suggest that again, uh, the first bio molecule monomers formed in areas where the sunlight enlightening could not penetrate and that hydrothermal vents provided the energy to convert the first prebiotic materials into the first bio molecule monomers. And so these air two competing theories that both have a lot of supporting experimental evidence. Uh, and over here we have a bio molecule monomer, and the example that's being shown is an amino acid, and so we may never know which of these two theories is correct. But we do know that bio molecule monomers were formed. And so the next video. What we're going to talk about is how did the first bio molecule polymers form? And so I'll see you guys in that video.

So now that we know how the first bio molecule monomers likely formed, we can now focus our attention on the polymers. So question. How did these Mawr complex bio molecule polymers begin to form if living cells were not around yet to produce them? And so the answer to that is that the first bio molecule polymers likely prelim, arised or linked together by proper alignment, using the charge mineral surfaces of objects such as clay. So let's take a look at an example here and in this example. What you'll see is we have these free bio molecule monomers that air negatively charged, and we also have this positively charged clay surface. And so there's an attraction between the opposite we charged components and notice. In the next image, we have thes bio, these negatively charged bio molecule monomers that are aligned on the positively charged clay surface. And if there's proper alignment between neighboring bio molecule monomers and the conditions are right, then Covalin bonds can form and link the bio molecule monitors together to create a bio molecule polymer, and there's lots of experimental evidence out there that shows that RNA and other polymers can prelim arise in this fashion, so it's likely that the very first polymers formed in this way. So now that we've got biomolecules polymers formed, the next step is to get these bio molecule polymers toe interact with one another, and that's where membranes and proto cells come into play. So membrane formation was important because it enclosed bio molecule monomers and polymers and prevented them from defusing away from each other, which increased the likelihood off. Those molecules toe interact, and so membranes formed via what's known as the hydrophobic effect. And we'll talk more about the hydrophobic effect later on in our course. But for now, I want you to know that membranes formed via the hydrophobic effect and that the formation of membranes was an important step for a B O genesis. So in our next example, what we're going to see is that we have thes phosphor lipids and the fossil lipids will talk more about in our later in our course. But in an aqueous solution, these fossil lipids clump together and they accumulate, and in the way that they accumulate, you can see that they create a phosphor oh, lipid membrane and notice that previous to the formation of the lipid membrane. We have these bio molecule monomers and polymers that are just floating around in solution, and they're likely defusing away from each other. However, after the formation of the membrane, we have our bio molecules, monomers and polymers enclosed within the membrane, which increases the likelihood of their interaction. And so this poll of molecules that are enclosed in a lipid membrane is known as a proto cell, and a proto cell is not a cell yet. It's actually the precursor to a cell, and it has the ability to acquire characteristics over a long period of time and develop into a cell. So in the next video, what we're gonna do is talk about how these proto cells link to the double origin theory of life. So I'll see you guys in that video.

so the double Arjun theory states two different things. The first is that Life has two origins, a coding system as well as an enzyme catalysis system. And the second thing that the double Arjun Theory states is that these two systems developed in completely separate proto cells, and so they developed in separate proto cells, and then later these two separate proto cells would have combined together. So let's take a look at our example down below and notice that we have to separate proto cells. And again, the double Arjun Theory states that a coding system developed in one pro tosel, whereas an enzyme catalysis system developed in the other proto cell. And then these two separate proto cells with different systems would have merged together to generate a single proto cell with both systems. And then this proto cell would have had plenty of time to acquire characteristics and to develop into the first life or the first cells. And so the next thing I want to tell you guys is that RNA, not DNA, is believed to have been the first coding material, and we can see that down here where RNA is shown as the coding system. And that's simply because, during the origin of life, it would have been better to have a single molecule that could doom or things. And RNA could do more things than DNA. RNA has both encoding and catalytic abilities, whereas DNA on Lee has encoding abilities. And so you might be thinking that this contradicts the double origin theory because we have RNA in a single proto cell that has a coding and catalysis system. But there is no contradiction, and that's because of this word here enzyme. So, yes, Arna has a catalysis system, but it doesn't have an enzyme catalysis system and recall the enzymes or proteins. And proteins and enzymes are way better catalysts than RNA. And so this proposal here, with an enzyme catalysis system, can do things that this coding RNA system cannot do, so there's no contradiction. So, uh, DNA is believed to have shown up later down the line. And so the very first cells would have had an RNA coding system, an enzyme catalysis system and DNA. And so to summarize the double origin theory, it states that life, which is shown over here on the far right, has two origins. The first origin is a coding system, which developed in one proto cell, and the second origin is an enzyme catalysis system which developed in a separate proto cell. And so that concludes our lesson on HBO Genesis and I'll see you guys in the practice problems.