 Hey everybody, Dr. O. I'm going to do a two-part video series where I quickly introduce all the different types of microorganisms that are going to be covered in microbiology. So I'll talk about the bacteria, the archaea, and the viruses here. So I want to talk very briefly about bacteria because there's entire chapters on them, but they are prokaryotes, which means, technically means pre-kernel or pre-nucleus. It means they don't have a nucleus. It also means they don't have membrane-bound organelles, but we'll cover all their structure later. One of the things that makes bacteria at least unique compared to the archaea is their special peptidoglycan cell walls, but there's an entire video on that. How they divide. I will talk about binary fission, which is how bacteria they divide later on. But binary fission looks an awful lot like mitosis. If you've ever learned about mitosis, the division of body cells, the only reason we can't call it that is because mitosis means that it is the division of the nucleus and bacteria don't have a nucleus. So their requirements as far as like temperature, pH, food, shockingly similar to yours, that's why you are such a good host for many of the different types of bacteria. So we will cover bacteria so much later, let's just kind of fly past them. Next we have the archaea. We will cover these less than anything else in the class, some for years. We didn't believe that we even came into contact with them. They are kind of, I like to call them prehistoric bacteria. They're similar to bacteria. They don't have the same cell wall though, but most of them, at least the ones that we know about, live in pretty extreme environments. It's almost like they've been crowded out. Like the bacteria showed up, they were better at evolving and adapting, and the archaea either had to go extinct or they had to find extreme environments to live in. So examples would be like your extreme halo files. They'll live in places with really high salt concentrations where other organisms wouldn't live. Also extreme thermophiles. They can live like in volcanoes and stuff, live at extreme temperatures where other organisms wouldn't live. So they kind of, most of them, so I used to teach, when I used to teach this class I used to say, you know, when I first started teaching it, I used to say, they're out there and they kind of matter, but you've never met them. But we, not only that, that's not true. We don't know of any real human pathogens per se, but there are archaea that can live in you, and there's an important family of them called the methanogens. So if you have an overgrowth of these archaea, especially in your small intestine, producing a lot of methane, the methanogens means methane-generating organisms, then they can actually de-constipation. So I think more people than you might think have a lot of methane being produced inside of them because of these organisms. And methane in your bowel can lead to constipation. So I think a lot of people that have the constipation form of irritable bowel syndrome may actually be dealing with an overgrowth of these methanogens. So there are breath tests you can do to look for things like methane gas and hydrogen gas. So I do think you'll hear more about that in the future. All right. The most important one for this video then is the viruses. So because we'll talk about viruses a lot, I especially like to talk about two types of viruses. This here is a phage virus. I'll circle it. Phages or bacteria phages are viruses that eat bacteria basically. So they play a major role in controlling bacterial growth. And I think phage therapy is going to become wildly popular. And then obviously we have some of the big viruses we talk about in class like HIV and Ebola, those types of things. So viruses are acellular, which means they're not actually cells. To be a cell, you have to have a plasma membrane, genetic material, DNA, and you have to have metabolism. So viruses aren't made of cells. They don't all have DNA. They either have DNA or RNA, and that's super important. And then they don't have their own metabolism. They need the host in order to survive and replicate. So they're not cellular. They're technically not alive, but not a big deal. They're still super important. I was at a conference one time where someone said that bacteria only exists so viruses have something to eat. I think that's pretty telling. You may have a quadrillion viruses living in your microbiome right now. So they're not cells. They're not alive, but that doesn't take anything away from their significance or the fact that they can be super, super scary. So viruses are generally just a core with genetic material, DNA or RNA, surrounded by a protein coat. This one kind of looks like a lunar lander. Like what's special about them is what's on the outside, so they know where to go. What cells are they looking for? How do they find them? How do they dock? So they don't have their own metabolism. They have to hijack the metabolic machinery of their host. Like we'll talk about HIV a lot where it actually takes over the CD4 positive T cells and uses that cell, turning it into a factory, making more viruses. So outside of living host cells, viruses will die some in hours, some in days, but they're not doing anything until they find that host metabolism. All right, so those are your bacteria, your archaea, and your viruses. I hope this helps. Have a wonderful day. Be blessed.