Microbiology - Antibiotics Mechanisms of Action

armonica student biology in medicine videos please make sure to subscribe join the forum in group for latest videos please visit Facebook Carmona Selena in this video I'm going to talk about the mode of action of antibiotics so we're not going to look into extreme detail but we'll just look at the overview in a way so a mode of action of antibiotics now we have to know that antibiotics either destroy or slow down the growth of bacterias so therefore if it destroys a bacteria it is bacterial seidel if it slows down the growth of bacteria its bacteriostatic here I am drawing a typical bacteria with cell membrane and cell wall the wall the cell wall and cell membrane structure I am drawing is characteristic of a gram positive bacteria but we will just assume it is any type of bacteria within the cytoplasm within the bacteria we have a circular DNA we can have RNA being synthesized and ribosomes here ribosomes will synthesize proteins the first type of antibiotic are the ones that I want to talk about other ones that target the cell membrane these antibiotics will disrupt the cell membrane function which means that they disrupt the phospholipid bilayer so here is the cell membrane and here is the cell wall known as the peptidoglycan they are different the antibiotic binds here to the cell membrane it will alter the cell membrane structure and will make it more permeable this will just disrupt the osmotic balance causing leakage of cellular molecules and essentially it will increase the word uptake leading to cell death examples of these drugs are poly mix-ins which I spelled wrong and Pauline's now Pauline's are actually specific Klee used against fungal pathogens but that's just a note to know that you can use our pollens that target some cell membranes impact in fungus so poly mix-ins and pollens target cell membranes other antibiotic classes target the cell wall these antibiotics will inhibit cell wall synthesis so these drugs are there for bacterial seidel they will cause bacterial bacteria to die example of these drugs are penicillin cephalosporin and bassett bacitracin opportunist all right all these drugs have different mechanisms of action when it comes to inhibiting the cell wall synthesis a good thing about these drugs is that it won't affect human cells because human cells do not have peptidoglycan x' we do not have cell walls penicillin and step for several sport our beetle lac dams and then you have the bacitracin and other glycol peptides that prevent the synthesis of cell walls as well antibiotics that disrupt the cell wall is pretty extensive and so hopefully i will make a video on that cell walls are important to bacterias disrupting the cell wall or preventing in cell wall synthesis will result in cell death the next type of antibiotic class is that ones that can inhibit here DNA synthesis or what's occurring here RNA synthesis so these antibiotics will inhibit RNA or and DNA synthesis so here the bacteria are typically having DNA replicated of course like so so we have antibiotics that prevent from DNA from being synthesizing for being synthesized these are quinna lanes and also a class known as Nelly Dixie acids and then of course RNA can be made when the deep from the DNA and there are drugs such as reefer myosin which prevents RNA synthesis and therefore protein synthesis other classes of antibiotics also inhibit protein synthesis itself protein synthesis is carried out typically by ribosomes which translate mRNA into proteins bacteria need to make proteins in order to survive however there are antibiotics that target either the 30s subunit or the 50s subunit of the ribosomes erythromycin and pleura finical target the 50s subunit of ribosomes whereas there are tetracycline streptomycin and Ginter myosin that target the 30s subunit either way this will disrupt the ribosomes from making proteins which will result in the bacteria obviously unable to make proteins so the bacteria is pretty much useless thus the bacteria can still be alive but it just is unable to make anything and so these antibiotics that target protein synthesis are bacteriostatic they prevent bacterial growth last type of antibiotic are the ones that inhibit folic acid metabolism so normally normally this green thing here called P ABA which stands for para and mineral benzoic acid it's a precursor to folate so the bacteria can can metabolize pa ba Baba into folate there are antibiotics out there that inhibit folate or folic acid metabolism C paba normally can be metabolized to folic acid within the bacteria and folic acid or folate is essential for the synthesis of adenine and thymine two of the four nucleic acids that make up DNA these antibiotics such as sulfur no sulfur no halides and try a methyl prim prevent conversion of PABA to Follett and therefore prevent a proper DNA synthesis you can say humans do not synthesize folic acid and so these back antibiotics are okay to take for humans and are selective towards bacteria I hope you enjoyed this short video on antibiotics thank you for watching

Channel: Armando Hasudungan

Views: 788,959

Keywords: Microbiology (Field Of Study), Antibacterial (Drug Class), mechanism of action, Cell wall synthesis, cell membrane synthesis inhibitors, inhibition of DNA and RNA synthesis, in bacteria, drugs against bacteria, protein synthesis inhibition, peptidoglycans, Erythromycin (Drug), penicillin, vancomycin, Tetracycline (Drug), antimetabolites, nucleic acid inhibitors, cephlasporins, polymixins, naldixic acid, macrolides, inhibitors, penicillin binding proteins, armando hasudungan

Id: IVBCrzjOl40

Length: 7min 16sec (436 seconds)

Published: Mon Dec 16 2013