hey everybody doctor here if you're watching this series and antibiotics you'll see we're switching gears so we just went through all the cell wall inhibitors and now we're gonna look at the major classes of antibiotics that inhibit protein synthesis so what you see here is a ribosome you've got the 50 s large subunit the 30 s small subunit and there's gonna be antibiotics that interfere with different parts making with what would be a 70 s ribosome with bacteria so one of the reasons this is a selectively toxic treatment in most cases is that bacteria prokaryotic cells have 70 s ribosomes whereas eukaryotic cells have 80s ribosomes now hopefully remember that our cells our mitochondria do have some 70 s ribosomes so there is always a little bit of a concern there and I think that might be why some people do have maybe some evidence of impaired mitochondrial function when they take antibiotics but that's gonna that's a discussion for another day so as a group first of all this is not true with all of them but if you're a protein synthesis and HIPAA ting antibiotic you're much more likely to be broad-spectrum right if you're a cell wall inhibitor you're much more likely to impact gram positive bacteria then gram-negative bacteria because gram positive bacteria care about their cell walls more than gram negatives do they have that outer lipid membrane the gram negatives do but all back all bacteria have to make proteins so these are much more likely to be broad-spectrum not always the case but they're also more likely to be bacteriostatic meaning they they slow or inhibit growth of microbes rather than killing them and that's again not always true right some of the antibiotics are bacteriostatic at lower doses and bacterial seidel that kill bacteria at higher doses or they're bacteriostatic alone bacteria sidle in combination and this is not a pharmacology class but you know we'll cover the basics there so you can see that the top group there at chloramphenicol the macrolides and ling cosas minds they're going to actually bind at the 50s large subunit of the ribosome and they'll prevent the formation of peptide bonds which means that amino acids can't be added to the chain that's gonna stop protein synthesis the amino glycosides which we're gonna cover here in this first video they actually bind to the 30s subunit but not in a way to stop the production of proteins it actually impacts the ability of these of these the ribosomes to do their proper proofreading which means they're gonna make faulty proteins that hopefully won't work and hopefully will destroy and the cytoplasmic elements are the internal structures of bacteria and then you have tetracyclines they're gonna binder that's 30s subunit as well but they're actually going to block the production of proteins so we'll cover them separately all right so I'll probably show you this village several times just to remind you of what we're looking at here the protein synthesis or translation inhibitors all right so the first group we're going to talk about here are going to be the amino glycosides and these are the ones that they do impact the 30s subunit just like tetracycline but they're the ones I was reading here they cause mismatches between codons and anti codons which which means the wrong amino acids gonna be put into the chain of proteins leading to faulty proteins that insert into and disrupt cytoplasmic membrane so that again that hopefully that will destroy the cell but the sense they are making faulty cells these are bacterial site I looked on the right-hand side there all the rest say bacteriostatic and that's usually bacteriostatic but in this case these are the ones that are bacterial seidel all right let's see streptomycin i won't a lot of school whatever whatever streptomycin and then these aren't these are all broad-spectrum streptomycin isn't used a whole lot anymore it was it was cheap and used a lot which means there's now a lot of resistance you think about every single time using antibiotic there's the risk that that you were forcing evolution forward a little bit and antibiotics basically cause microbes to leap forward when it comes to evolution but it is it is still useful it's effective against micro bacterium which means that this could still be useful against Mycobacterium tuberculosis causative agent of TB and Mycobacterium leprae so it does still have some uses but you don't see it used a whole lot anymore let's see gentamicin another broad-spectrum one the reason this one is important is it's useful against Pseudomonas infections and Pseudomonas infections can be a problem for everyone we've talked about it as one of these potential you know coming up nightmare bacteria but Pseudomonas infections are a real big problem particular cystic fibrosis so it's used a lot so gentamicin is used a lot to treat Pseudomonas infections in patients with CF cystic fibrosis next we have neomycin so neomycin is used topically so this is going to be the neomycin that's in your triple antibiotic or neosporin that's the key thing with neomycin there all right the problem with some of these antibiotics yeah so we think we said streptomycin is not used a lot but it's useful against micro bacterium neomycin is just used topically really gentamicin used for these cystic fibrosis patients there's a lot of toxicity concerns of these antibiotics so nephrotoxic which means they impact the kidneys neurotoxic nervous system I think they can impact the ears as well so these antibiotics if you're going to use them you want to make sure that it's that it's worth the risk and that's why a life-threatening Pseudomonas infection of the patient's patient with cystic fibrosis or tuberculosis which is a which a huge scourge on our planet they might be worth some more risk but for other infections we moved on to other types of antibiotics all right so these are the I just wanted to quickly introduce the protein synthesis inhibitors because this happens to be the first video in the series and then also these are your aminoglycoside antibiotics I hope this helps I have wonderful day be blessed