so to finish up chapter 1 part 2 we're going to talk a little bit about microbiology and microbiology and the history of microbiology itself so we're gonna start about four hundred years ago and it seems like a lot but remember we went back four billion years ago in the last section so we've gotten a lot more current at this point. So about four hundred years ago around the time of a man named Francisco Redi the general consensus among people one that life very commonly arose through something called spontaneous generation or what we like to term abiogenesis now we're talking abiogenesis again break down the word in "a" meaning with out or absence of the "bio" life and "genesis" creation. So abiogeneis the thought here is creation without life the gist of spontaneous generation is that if four hundred years ago/ five hundred years ago you walked outinto a barn and there was a sack grain that had left out on the floor of the barn and mice came running out of the bag of grain that would be because if you leave grain long enough eventually it turned into mice eventually it develops mice what is saying is that you don't need another living organism to make a living organism that grain is sufficient to make mice. now at this point in time the hope is and and obviously we don't believe this we actually know that it not abiogenesis it's what we consider biogenesis, that living things come from other living things and I'm eating Francisco Redi was actually trying to prove this to his peers so aside from the grain and the mouse we can also look at maggots beingderived from meat if you leave meat out long enough eventually the meat looks like it grows maggots Redi tried to disprove this is very common thought that meat graws maggots with a pretty simple experiment three individual flasks and placed meat in each of the flasks left one completely unsealed, sealed the other and then covered the third flask with gause or with cheesecloth at the time and try to get people to wait and see what happened in and pretty much everybody should listen Francisco we know what's going to happen the meat is going to grow maggot because everyone knows maggots come from meat. if you leave meat out long enough it's going to grow maggots and Francesco said I don't think that's what it is I think something else is going on we're just not being observant enough so he left the meat in the flask out for a time period and eventually the unsealed flask did absolutely "grow" maggots and everyone that yeah Francisco we know that in the sealed flask however what you see is that there are maggots in the sealed flask and the actual consensus was a well that's because you're suffocated them and Francisco's that but wait wait what about no one covered with the cheesecloth/with the gauze? it's very breathable air could get in there why are there no maggot the third flask and Redi said it's not the meat that's growing the maggots. if you watched while this was happening what you would notice that flies we actually attracted to the smell of the decaying meat and the flies that can get anywhere near the meat were actually putting the maggot there and he saw this because if you look, the fly still smell the decayed meat in the cheesecloth covered flask and the maggot actually grew on top of the cheesecloth nobody believed Redi unfortunately he was still considered to not be correct at this point in time eventually about two hundred years later we give some credit to a man named Louise Pasteur Pasteur frenchmen actually did a lot in the way of microbiology is very commonly considered the father of microbiology and Pasteur disproves a biogenesis with an experiment that's very similar to Redi's in Pasteur's experiment what he'd noticed as he tried to work with various types of organisms including microorganism was that if he left the media, the growth media for the microorganism out long enough eventually it started to kind of get cloudy and change color we all done this left something in the refrigerator too long and pull it out a liquid that is supposed to be clear suddenly has cloudy gook in it and you know not to drink that or use it hopefully because it is contaminated. So Pasteur says where does come from I didn't put it in there may be something in the air maybe just because we can't see these organisms there floating around in the air and they're actually making their way to the media and Pasteur attempted to prove he heated the growth media and by heating the growth media it sterilizes it and removes all organisms good bad ugly you name it everything is gone and then he took the necks of the flask the opening the flask and bent into the what we call swan neck curve, now the goal of this swan neck curve is that because of the way this is curved you will not actually get air down into the media Pasteur did this with several flasks swan necked all of the necks to the flasks and took some of the flasks and left them intact and other words the neck was left alone the air cound not get down the growth media and then took several other flasks and broke off the swan neck so they had all gone through the exact same condition the only difference is broken vs intact neck as the time went on one thing Pasteur noticed was that the broken flasks actually seem to change color/get cloudy and have growth them pasture took from this the fact that just because we cannot see something that does not mean that it is not there just because you cannot see your heart beating but I know that it's there I cannot see viruses in the air but I know that they're there so we think this is Pasteur disproving abiogenesis thing that there's something out there just because we can't see it happen doesn't mean that it doesn't happen. It took two hundred years poor Redi rolled over in his grave at this point and Pasteru was touted as being be disapprover of abiogenesis now if we're going to talk about microbiology we obviously have to talk about the microscope most of the credit here not necessarily for inventing the microscope but for perfecting them well, I wouldn't say perfecting they still need work but for making great stride and how the microscopes work. around the 1660s nothRobert Hood and Anton van Leeuwenhoek added to our abilities indicate the microscope a little bit more of a scientist studying objects or specifically while van Leeuwenhoek was manufacturing simple microscope not for scientific use but for use to further his business originally van Leeuwenhoek was working for a textile merchant which would mean that he was using the microscope to take thread counts the higher the thread count the more expensive the fabric and eventually he became his own self made microbiologist looking at anything he get his hands on its sparked an interest in him you name it van Leeuwenhoek looked at it very often he saw small moving organism and what he was looking at he actually gave them a name you call them "animalicules" we have since done away with this term because we know that they are not just small animals there are lots of different types of organisms over his lifetime van Leeuwenhoek constructed about two hundred and fifty small microscopes that actually got really good magnification up to about 300 X which is about 300 times normal vision sovan Leeuwenhoek got very very good at making microscopes and a few other important figures when it comes to microbiology Joseph Lister actually pioneered the use of aseptic techniques and surgeries in the mid 1800s aseptic actually mean with out contamination up until this point we saw a lot of use of equipment in one surgical suite moving into the next now we obviously would not dream of doing this a lot of individual not washing their hands in moving from one surgeries to the next not changing their clothes and moving from wonders reach the next So sometimes it is the simplest of ideas and Lister saying things like a guy we want to clean off the saw, you might want to clean off that scalpel before you use it on someone else when it comes to the handwashing however Holmes and Semmelweis Oliver Wendell Holmes and Ignaz Semmelweis actually pioneered importance of handwashing mainly because one thing that they notice was that women that gave birth in hospitals actually had a much higher frequency of death than those that were giving birth at home at the time this is the late 1800's sort of the turn of the century 1800 -1900 and part of that actually had to do with the fact that physicians were not washing their hands between deliveries among patient Pasteur and his contributions with aseptic technique also the introduction of pasteurization which we will talk about more when we get to chapter 9 I believe he also conducted some of the first studies that link human disease to infection probably a little bit more well known for that and who I would consider a major contributor to microbiology is a man named Robert Koch (German so it depends on your pronunciation sometimes it's pronounced "coke") developed a series of postulates that actually help verify that certain diseases were caused by specific types of microorganisms he managed to link the disease and the microorganism coming up with what we now considered germ theory of disease not a particularly technical theory when it comes to science Germ Theory states that germs cause disease then we know this now it is a widely widely accepted tenant so the last little bit of this chapter Cellular organization it's an introduction and chapter four we're going to spend a lot of time talking about the eukaryotes in Chapter three we're gonna talk more about the prokaryotes but as a reminder the Eukaryotes you're looking for organelles if it has mitochondria rough ER smooth ER a nucleus any of these showing up is going to mean it is a eukaryote! Prokaryotes lack all membrane-bound structures So Rough ER, Smooth ER, nucleus, and Golgi mitochondria all of these are membrane bound structures any instance of these (i.e. possibly on a test) automatically indicate that you are dealing with a eukaryote even if others are missing multicellularity is also something that is exclusive to Eukaryotes. prokaryote are ALWAYS unicellular organisms they do not exist as multicellular organisms the prokaryotes what we're talking about here is bacteria or Archaeans. Honestly a lot of times the terms bacteria/prokaryotes are used sort of interchangeably they're gonna be about 10 times smaller than Eukaryotes they are not going to have any organelles see here this is a much simpler diagram nowhere near as many arrows. all of them will be microorganisms now the viruses are gonna be their own special category We'll do more when we get to chapter 5 these are not independently living organism they're pretty much bundle of hereditary material that is DNA or RNA coated with a protein they miss out on a lot of the tenants of what it means to be a living organism in essence I will commonly referred to these as host hijackers so there you have it this is the end of chapter one and we'll move on to the next chapter in the next lecture