Hey everybody doctor O here. In this video I'm going to do a quick overview of all of the keys for structure of bacteria. So if they need, if I need to give you anymore detail i'll do seperate videos on those topics. Im just going to use this image and follow right along here in clockwise fashion so starting at the top with the fimbriae so fimbriae in a word think attachment so attachment is very important because if an organism can't attach then it can't colonize an area which means it cant infect and area and lead to disease so there are some examples. Like uh for example if you take ecoline remove its fimbriae it actually will not even be pathogenic the pathogenic strains will be colie so fimbriae think attachments i always think of crackle burrs or some people call them sticker burrs when you walk through the tall grass and you come out and you shoe lace and socks are covered in these little structures well that's kinda what these fimbriae do so they are necessary for attachment which is really the first part of an infection okay so that's fimbriae. next we have cytoplasm so cytoplasm is basically everything inside the cell membrane or plasma membrane exempt for what is in the nucleus which doesn’t matter here because bacteria don’t have a nucleus so cytoplam think all the guts on the inside of a cell now um compare that to cytosol. Cytosol would just be the fluid inside of this just in case you hear those words uh they're not exactly interchangeable next we have the ribosome so the ribosome is the site of protein synthesis or the site of translation if you want to use the fancy terms so um bacterial ribosomes are called 70s ribosomes stands for uh s stands for svedberg unit as of must of our human are eukaryote ribosomes are Ads so thats an important target for a lot of antibiotics so ribosomes think protein synthesis the nucleoid or nucleoid region is where the dna is in a bacteria so we obviously eukaryote have a nucleus that that protects our dna bacteria dont so the bacteria or the but all bacteria have one circular chromosome so its its tucked into this nucleoid region so thats what the nucleoid is next we have inclusion so inclusion would be um really storage vesicles would be the best way to think of it this would be this bacterial would be storing glycogen so it could be used as a fuel source etcetera etcetera so inclusion just think storage vesicles. Next we have the plasmid so plasmids are wickedly important we’ll talk about them in a couple other videos the definition of plasmid and ill put it up on the screen because its hard extrachromosomal genetic material so it's telling you its genetic material its DNA but its not part of that one circular chromosome that bacteria have the reason these are important are these are vectors these there self replicating they can make copies of themselves and they can actually they're transmissible so this bacteria here could quote on quote infect its neighbor with a gene that actually gives it some sort of resistance factor that teaches it to evade antibiotics or evade our immune response etcetera this is part of the reason that bacteria can evolve so quickly alright thats the plasmid next here we see the flagella or the flagellum so um these are actually way more complex then then eukaryotic flagella so like the flagella on a human sperm is just a single whip like flagella but bacteria can have hundreds of flagella on there surface and they have a rotary motor that actually powers them so its quite fascinating the way i like to think of it is the bacterial flagella has to be this powerful complex mechine uh uh the formor editor of the journal nature called it the most complex machine in the universe but the reason for that is because bacteria are so tiny and and theres so much surface tension and and forces holding water molicules together this bacteria swimming through water would be like you swimming through peanut butter so kinda interesting alright next we have a pilus so there the the an organism that has a pilus would have usually one or two of these and the pilus is generally used to transfer DNA now they can be used for attachment and movement but i like to say when i hear hooves i think horses the most important thing the pilus does is to transfer genetic material in a process called conjugation so the pilus might be names uh a sex pilus or conjagation pilus as well next we have a capsule so obviously not all of bacteria have capsules but they definitely make them more dangerous they increase virulence which virulence is a term for how pathogenic how dangerous a organism is uh the capsule is a a substance polymer substance usually made of uh carbohydrates and or proteins that coats the outside of the cell and the reason the capsule makes these organisms more dangerous is because it helps them evade phagocytosis so many of your immune cells will engulf and destroy bacteria but they cant or have a very hard time doing that with a bateria that has a capsule so thats the function of the capsule we’ll do a separate video on that next we have the cell wall there's lots of different cell walls but the two key ones would be grand positive and grand negative we’ll do a separate video on that but the function of the cell wall does give bacteria its shape and its structure but its primary for protection but its not like protection think about like a fortress wall its primarily to protects a cell from bursting so the plasma membrane is very weak and fragile especially in bateria so if water were to rush into this cell um it the the cell could literally pop if it weren’t for the cell wall so the cell wall think shape and structure but also protection then the last structure here uh on this diagram is the the plasma membrane aslo known as the cell membrane so all living things um are composed of cells and all cells have to have a plasma membrane so plasma membrane is a selectively permeable membrane which means it ke it forces somethings to stay in a cell forces other things to stay out of cell and its also where things move in and out so the function of the plasma membrane is to keep the things that are needed in a cell and while helping to get rid of the things that we have have to get rid of like waste products so very very important there alright so those are all the key structures here of a bacterial cell or a procarial have a wonderful day be blessed.