hi everyone Dr hinke here for our final section of chapter one our introduction to microbiology we're getting a big broad overview of everything that we'll be covering so right now I'm getting familiar with the terms so she's generally recognizing these are the concepts we'll be exploring in more depth is what we're going for so if as you read these or hear about the organisms like I don't know anything about these that's right because we're at the beginning of class um so that should be how you feel but we're building some some foundational knowledge that will expand on as we go so let's take a look at our our points for this section here we are and so section 1.3 just covers the types of microorganisms that are studied in microbiology our objectives for this section by the end of this you should be able to list the types of microorganisms and acellular infectious agents and their characteristics you should be able to describe the similarities and differences between archaea and bacteria you should give examples of different types of cellular and viral microorganisms and infectious agents and provide an overview of the different areas in the study of microbiology the first if we look at microbes what we're talking about when we talk about microbiology and microbes are things that are not visible with the Naked Eyes and this image shows us this scale that we're talking about we don't become visible to the naked eye and to learn about 100 micrometers so raw gigs you can see those in the past they're bigger they're visible um an average about one millimeter uh human egg that's the largest cell in the human body very tiny but but at about the limits of visibility as well as following a typical plant animal cell there's a lot of variation in here as we can see will range between 10 micrometers some are smaller like red blood cells um and some blue booty larger but between 10 micrometers 100 we look at this scale along the bottom of this image each unit is a tenfold increase so this isn't just voices big three times four times this is ten times larger 100 times larger than this first atom 1000 and so on Ten Thousand we go up five one by ten each unit so a red blood cell is about one-tenth the size of other animal cells the mitochondria an organelle within eukaryotic cells like ours that's responsible for producing energy um is and 102 units smaller about 100 the size of the entire cell mitochondria are similar in size too many bacteria and we'll talk about why that is in our next chapter then as we can see there's a range of viruses we have a very small polio virus of blue virus smallpox virus but even the smallpox one of our larger viruses is smaller than a bacteria um almost half as large and then of course if we think about this scale as we go down our viruses are complex infectious organisms we'll learn all about those but they're made of a nucleic acid surrounded by a protein so they're made of multiple different types of molecules organized in a specific way that means they contain proteins that protein go so proteins must be smaller proteins are a macromolecule a big molecule but they're still smaller they're the building blocks of larger things so they are one of the welding blocks that make up viruses so obviously proteins the building blocks have to be smaller than the entire thing lipids example are plasma membrane that surrounds all cells is made up of phospholipid bilayer they must be significantly smaller if it takes millions of them organized into an envelope to surround the cell so when we look at that molecules must be smaller than the things they make up and atoms which make up molecules must be smaller than those molecules um so this just sort of makes sense as we go down here so our living things when we talk about microbes we're looking at microscopic organisms things that are not visible to the naked eye um and really we're looking down at this end we will look at some eukaryotic cells there are some prokaryotes some eukaryotic cells that we'll study in microbiology those that are microscopic or at least one stage of their life cycle so the specific organisms ever primarily bacteria we spent a lot of time with bacteria you think about bacteria again smaller than our own eukaryotic animal cells about the size of one of the organelles in Love cell the mitochondria the PowerHouse of ISO most bacteria are harmless to humans and in fact the majority of bacteria are helpful they recycle nutrients they remove waste and toxic materials from ecosystems and they serve as the primary producers for many food webs some bacteria are pathogens a pathogen is an organism that causes disease that will be the focus because we are a clinical microbiology class most of you are preparing for healthcare Fields so while we focus on pathogens and just know that some are pathogens but the majority are not the majority provides helpful services and are essential for our existence and so valuable so bacteria have a wide range of metabolic capabilities it can grow in a variety of environments we already talked about the fact that bacteria are ubiquitous we find them everywhere the archaea this is our other domains we have our domain bacteria are the Wayne Archaea and then our domain eukaryotes the Eukarya nucleated cells organisms with nucleated cells the archaea do not have a nucleus they are similar to bacteria in size um but we've discovered that they have distinct molecular differences I'm in the membrane makeup in there in there sell wall makeup shoot a peptidoglycan as opposed to the cell wall of bacteria which is peptidoglycan there's sort of this transition species between the bacteria and the eukaryotes they have some uh of their components that are more similar to eukaryotes than they are to bacteria these are often found in extreme environments so we sometimes hear them referred to as extremophiles so very cold very hot very basic very acidic high pressure high salinity um environments that other living things would have difficulty living in find archaea have adapted to those and survive and thrive in those there are no known and pathogens in the archaea um but as we learn more and more about those we are finding that they aren't all extremophiles they well many of them can be and are extremophiles they're the groups were most likely the group were most likely to find in these extreme environments uh they also live in some not very extreme environments including on and in our bodies but none of these are known pathogens so we won't be spending a lot of time on the archaea so if we look at our bacteria the way we differentiate our bacteria often is based on morphology this is our first differentiation remember we talked about taxonomy and we start with domains and then we classify to more and more similar and more and more similar until we get down to genus and species some of the very first classifications that we do to separate into smaller and smaller and smaller units in our taxonomy of bacteria first is shape and that semi-rigid structure that pepinoglycan gives us a rigid uh external support structure so the bacteria have distinct shapes because of that cell wall uh it's in common morphologies that we'll see a lot in the lab and we'll talk about frequently uh are spherical or Focus cocci plural bacillus which are Rod shaped Orbison plural vibrio are comma shaped so comma slightly curved priscillas we can have cocoa bacillus cocoa bacilli which are not quite as oblong it's from this cross spherical but a little bit more oblong slight modification um kind of a combination of our caucus and bacillus bacteria so cocoa with shalai and then we have spirulum which are um spiral shaped and flexible uh and spyroots which are very illegal rigid like a corkscrew structure it's our general broad overview of bacteria and archaea prokaryotes Pro before carry out and not are the seeds that nucleus so we also have some new periods that we study in microbiology are eukaryotic microorganisms uh many of them fall into the eukaryotic Kingdom Protista remember we have the kingdoms Animalia lamb tide fungi and protista in our eukaryotes the protists this is a kingdom that's not based on evolutionary history and relationships but based on we don't know what else to do with you so we're going to put you in this single-celled Kingdom for now now that we have this great molecular technology and we can look at these organisms on the DNA level the molecular level in their bio molecular makeup their DNA and RNA we're able to figure out what those evolutionary histories are and so in taxonomy right now we're in the process of dividing those into Super groups based on an evolutionary history so this is really a an influx Kingdom at the moment but right now um we subgroup the protists basically by how they get their nutrients and their energy so in within the protest with some single-celled organisms that are plant-like uh you know photo autotrophs okay both photosynthesis we include the algae in here most algae are single-celled phytoplankton aqueous floating in the oceans but even the macro algae fall into the protista group they're the one exception to that single cell rule um because LG don't have the same complex structures that plants do then we have the fungus-like protists they are sap probes they neither eat nor photosynthesize but they absorb nutrients from the environment around them they release EXO enzymes enzymes outside of their body that break down dead and became organic matter and then they absorb the nutrients so they acquire their nutrients and energy and I'm just like manner or sad probes so some things like water molds and slime molds and then we have the animal like protists for those as protozoans they're animal-like or female heterotrophs that means they eat other living things and then we have some that are both photosynthetic and heterotrophs they have the ability if there's no food available they can photosynthesize they have chloroplasts that photosynthetic organ that plants have and if they're Stark Earth there's food around and it's easier they'll eat other organisms and you can lean are an example of that for anyone who's taken 101 and 102. so our protozoans the animal-like group are primarily the ones we'll focus on we won't look at algae at all photosomes are very diverse some are free living at others are applicant internal parasites they must live inside a host and these are the ones that can be pathogenic typically are often we differentiate direct or differentiate the protozoans by how they move whether that's your pseudopods fake feet right pushing out their cytoplasm making cytoplasmic extensions and then pulling themselves forward with those or through flagella with like tail cilia short or like extensions hair like extensions and some are non-rotile they don't move in our adult phase so we'll look at protists typically single cell protozoans fungi it's another Brew we think about mushrooms on our pizza well they're fungus they're not microscopic we do have some that are multicellular not microscopic red mold um lots of fungus that we can see as a mold especially those are the multicellular form but we also have some single-celled varieties yeast single-celled fungus many fungus are dimorphic meaning they can either be a single-celled yeast fungus or they can be multicellular made of piping long threads multicellular threads like you can see with bread mold out of the molds so they can be yeast to our molds either one and often the environment the conditions in the environment the temperature the pH the moisture will determine which form they take fungus are not photosynthetic as we've talked about with the protists that our fungus like they acquire their nutrients by decomposing debtor decaying organic matter in the environment around them externally and then absorbing it and then our another group of eukaryotic microorganisms we'll look at are the helmets worms these are multicellular they can be very large um three meter long tapeworms we study these in microbiology and considered microorganisms because many of the disease-causing helmets have microscopic eggs and larvae and that is primarily primarily when they are transmitted is through the release of eggs and larvae but often in water and then that's how they get into a new host and grow into that larger macroscopic worm that we think of when we think of worms we also have an acellular group of microorganisms that we study a cellular that prefix a means not not cellular I will look at some other types as well but viruses are the primary one we'll talk about now let's talk about prions but viruses are obligate intracellular parasites sometimes you'll see them referred to as obligate intracellular infectious chemical compounds because they're not living they have to use their host cell to multiply is that word obligations we must be inside a host cell outside of the host cell viruses are inert they are acellular they're not composed of cells so they're not considered a living so in order to be considered cellular we have to have cellular level organization meaning we have to have excited a cell membrane surrounding cytoplasm aqueous solution that has dissolved substances this cell requires the resources it needs and nutrients it needs of a building block compounds and needs and within that cytoplasm we must have DNA gotta have the instructions for how we will metabolize or function we have to have ribosomes ribosomes or organelles where we make proteins since chemical reactions out of our metabolism requires proteins enzymes for us to function without those ribosomes and ability to build our own proteins we don't meet many other requirements that it takes to be considered living so all living things have organization and they have the cellular level of organization that at least viruses do not have that metabolism is the sum total of chemical reactions in a cell and so must have the ability to take small molecules and build large ones and the ability to break down large molecules to release energy to do work viruses have no metabolism they're unable to carry out chemical reactions on their own they must use the host cells and Machinery to do that living things have to be able to reproduce viruses can only reproduce when they're inside a host and use the host sales Machinery they do have adaptations because adaptations just with virtue of the accumulation of mutations that allow an organism to survive so because when they replicate inside a host cell using the host cell Machinery mistakes can happen we can have mutations they do have those and another criteria for living things is they have to be able to respond to stimuli this is a big debate debate among biologists and virologists um because the only interactions that viruses have with their environment are chemical reactions so is it a legitimate response to stimuli or is it just a chemical reaction that would happen anyway uh is that an actual motivated response to stimuli based on senses so there's some debate on whether or not that chemical reaction is a response so these are the six criteria for something to be classified as living and you have to meet all six of those viruses do not and so they're not classified as living only as an obligate infectious particles I will get interest cellular infectious particles but viruses will spend quite a bit of time on viruses so our areas of study when we talk about microbiology it's a broad term and there are lots of sub-disciplines so all those different types of microbes can be their own area of study so we can be we can study bacteriology we study bacteria structures functions metabolism of bacteria mycologies mycologists study fungus protozoologists study protists are protozoans parasitologists often study both protozoans not so parasitic protozoans as well as helmets virology is the study of viruses and immunologies included in this because that's a study of an infectious agent the interactions between an infectious agent and the host immune system so those are the main broad areas but microbiology can also be divided into sub-disciplines based on a habitat or environment of the micro or specific function so we can have marine or aquatic microbiology in my my background in Marine microbiology environmental microbiology a little broader not just in aqueous environments we can have agricultural microbiology looking specifically at microbe interactions with agriculture Geo microbiology and we study the biogeochemical cycles that bacteria and Archaea and other microbes are intricately involved in aeromicrobiology you can study the bacterial they're present in the air we can focus on specific areas just like with Agriculture and microbiology and can focus on Veterinary microbiology or Astro microbiology you get microbes that may exist outside of our atmosphere on other planets in space those are all different areas or subsections within microbiology that people can focus in it's one of my favorite quotes if you remember in our previous unit we talked about Carlos and the Box they used ribosomal RNA to come up with the most recent and most accurate phylogenetic tree that we have I'm helping to divide out the archaea and the bacteria seeing those differences and so Carlos that's a great boat about why are we studying microbiology why should we care and hopefully this will pique your interest a little bit so that you're taking this class not just to check this box off not just because you have to do it to get into the nursing or some other Allied Health field but because this is what you will be doing in most health Fields this is what you will be doing every day so it's intricately involved it's important that you know this but also why should we care we can't see these things but let's do a thought experiment and take these things away let's take all the bacteria in the world away do you know what's going to happen all the life that we can see with our Naked Eyes all that life is going to disappear in short order the microbial world is the basis upon which our whole ecosphere rests and without it there's no multicellular life and The Humbling thought is if you do the converse and take away all the animals and plants you'll see big adjustments in the bacterial world but it will still be there growing happily along and evolving we need them that they don't need us with this humbling thought isn't it and also shows the importance of understanding microbes and their function all right so let's go ahead and check our learning from this short section match each description with the appropriate microbiology subdiscipline so a study of how antibodies are released in response to a pathogen which of those sub-disciplines studies antibodies response of our immune system the presence of a pathogen she said Immunology the study of fungi including their genetic and biochemical properties taxonomy and their ability to cause illness or disease fungus mycology that's the study of the morphology ecology genetics and biochemistry of bacteria I'm just going to add allergy bacteriology and the branch of biology or medicine concerned with the study of parasitic organisms all right a blank is a disease causing organism so now everybody should know the correct answer to that is not a bacteria not all bacteria cause disease germs is a generic word that really means nothing we want to be more specific what causes what's a disease causing organism correct term is a pathogen which of the following is not considered a microorganism mosquitoes bacteria protozoans or fungus well mosquitoes can be small but they're not microorganisms and fungus can be large but not conformities are so we can study those so it was not considered a microorganism about this one which of the following is true of the microbial world all microbes are harmful humans could survive without microbes many microbes are helpful or most microbes are pathogenic Ally everyone now understands that many microbes are helpful the study of viruses is called Urology okay I'm just going to add allergy and which of the following indicates how bacteria and viruses compare in size bacteria are indistinguishable from viruses bacteria are much larger than viruses bacteria are much smaller than viruses or bacteria are similar in size to viruses like everybody remembers that chart that we started out with that shows bacteria are much larger than viruses ten to A Thousand Times larger Bell quick review learning objectives but at this point everyone should be able to list the types of microorganisms like acellular infectious agents and their characteristics but those we'll be studying describe the similarities and differences between archaea and bacteria pseudo peptidoglycan and archaea versus peptidoglycanion bacteria no archaicans disease some bacteria can be pathogens and then there's some other distinct molecular differences in their cell membrane the ribosomes and their function you should all be able to give examples of different types of cellular and viral microorganisms and infectious agents and provide an overview of the different areas in the study of microbiology this third one and the first one okay saying the same thing but hopefully we are all ready to do that and now you are hopefully very excited for what's to come as we dive further into all of these things we briefly touched on in chapter one I will sing in chapter three