DISCOVERY OF MICROBES Our earliest knowledge of microbes started in 1835 but they ve been on earth for approximately 3 8 billion years o This makes them the oldest organisms with modern eukaryotes what makes up the human coming into perspective about 2 billion years ago study protozoa bacteria fungi viruses algae and diatoms Microbiologists Microbes noncellular o When microbes are in VERY large numbers you can see them with the too small to be seen with naked eye can be cellular and naked eye mold on bread Microbiology MICROBIAL COMMUNITIES o All habitats are different and each microbe is habitat specific algae needs Lakes human mouth sewage plant etc is the study of microorganisms light HOW MICROBES IMPACT HUMANS AGRICULTURE o This includes things such as cows and plants o Plants have bacteria to help them perform natural processes soybeans such as getting rid of nitrogen ENERGY o Biofuel o Cellulose Corn starch Glucose Fermentation Ethanol FOOD o Canned goods alcohol beer cheeses etc o Saccharomyces cerevisiae yeast used to make beer o Canned goods have added preservatives in order to keep microbes from developing MICROBES AND DISEASE Use to cause A LOT of disease o Microbes cause 25 of death worldwide o EXAMPLES HIV respiratory infections diarrheal disease TB Malaria Meningitis Pertussis Measles Hep B PROKARYOTIC AND EUKARYOTIC CELL Eukaryotic cells are A LOT more complex DNA is enclosed in nucleus in eukaryotic but is free floating in bacteria prokaryotic ORIGINS OF EUKARYOTIC CELL now called mitochondria Ancient eukaryotic cells came in contact with respiratory bacterium which is Came to be a respiratory eukaryotic cell From taking it in it provided the cell with ATP which it needs to do BACTERIA TAKE IN EVERYTHING After mitochondria cell took in cyanobacteria photosynthetic bacterium The cyanobacteria make ATP out of light Chloroplasts today Gives cell advantage because it has two ways to receive ATP to do work work Not all cells evolved like the cells in our mouths 3 DOMAINS OF LIFE 1 Bacteria 2 Archaea 3 Eukarya Carolous Linnaeus decided names for living organisms after observing mainly physical attributes Said we had PLANTS and ANIMALS Name things by their first and last name he started this Naming is mostly Latin In 1950 we figured out the structure of DNA Carl Woese sequenced organisms by DNA 1990 and said that it was a lot more complex than animals and plants Also said that DNA can reveal secrets Today we group things by a GENUS and SPECIES Bacteria DOES NOT have a kingdom Bacteria has a large number of phyla which don t change often Archaea and Eukarya also have a few phyla but are always changing and perplexing due to research ROBERT HOOKE First to describe cells and microorganisms Created a very small microscope He drew fruiting bodies of yeast NOT bacteria Looked at cork plant cells ANTONI VAN LEEUWENHOEK First to describe bacteria Started the study of bacteria COMPOUND LIGHT MICROSCOPE Used for light microscopy like bright field and fluorescence 1000x magnification 0 2 micron limit of resolution making something bigger Magnification Resolution separately and not as one organism Microscopy allows cell shape and arrangement to be seen how much space is needed in between cells in order to see them o Like the chains of rod shaped Lactobacillus o Stain cells because they are 70 water o Cells stay in one shape and arrangement Staphylococcus means grouping and round Mycoplasma Streptomyces no defined shape due to no cell wall fungal bacterial forms branching o Microscopy allows you to see the branching structure o Also can see endospores by Bacillus and Clostridium species Those are very hard to dye because they re inside of cells Microscopy allows you to see pathogens o Mycrobacterium in pathogens prevent stain so you have to acid fast them in order for the stain to be seen Microscopy allows you to distinguish between Gram negative and Gram positive o Gram developed a staining protocol since all cells stain differently o Gram pink Gram purple o You can determine what organism needs to be treated based on the Gram stain ELECTRON MICROSCOPE 200 000x magnification Couldn t see a virus until the electron microscope 2 types Limit of 0 2 0 4 micron resolution o Transmission TEM You have to embed the cells with plastic and use diamond to for observing internal cell structure cut them in half o Scanning SEM for 3D imaging and viewing the surfaces of cells Have to plate the cells in gold in order to see them Mycrobacterium leprae bacteria that cause leprosy main host is the armadillo just because you come in contact with it does NOT mean you will contract it CELL STRUCTURE AND FUNCTION CYTOPLASMIC MEMBRANE o Also called cell or plasma membrane o Surrounds cell and acts as a barrier o Has a lipid bilayer fat Every cell has lipids proteins carbs and nucleic acid Things that cant pass due to their charge If there are a lot of solutes outside protein moves stuff in after molecule binds to protein No connection between two layers Heads are hydrophilic tails are hydrophobic o Hydrophobic interactions keep the bilayer together but high heat can denature them o Archaea DO NOT have a bilayer they have a MONOLAYER no space covalently bonded won t denature o Water passes freely but other molecules must go through proteins to enter exit cell transport proteins CELL WALL o Peptidoglycan is found in most bacterial cell walls that surround the cell membrane has many layers o Cell wall is outside of cell membrane o Telchoic acid binds things inside of cell o 2 sugars involved N acetylglucosamine NAG N acetylmuramic acid NAM Peptides strings of amino acid form cross bridges because they link sugars and hold them together o Have to penetrate in order to kill bacteria but things don t like to cross Gram usually structure o Cell envelope cell wall cell membrane o Mycobacterium is VERY hard to penetrate due to mycholic acids in wall weakens cell and than antibiotic kills it takes 6 9 months Gram thin peptidoglycan layer but have another membrane outside of peptide layer Have 2 lipid bilayers and 1 pep Layer Outer layer has lipid A and sugar extensions Body recognizes gram bacteria by outside sugars Sugars are species specific If gram cell dies it falls apart Lipid A can become free and cause a fever PLANTS ALGAE FUNGI o Eukaryotic o Doesn t have a peptidoglycan layer o Cellulose is main sugar o Fungi have chitin made of NAG CELL SURFACE STRUCTURES longer protein filaments used for conjugation