Notes for Exam 1 | Introduction to Microbiology with Lab | BIOL 2230, Study notes of Microbiology

Download Notes for Exam 1 | Introduction to Microbiology with Lab | BIOL 2230 and more Study notes Microbiology in PDF only on Docsity! Microscope: - 1632-1723 Anton van Leeuwenhoek: first person to see bacteria - 1840-1905 Ernst Abbe and Resolution: resolution is what defines - 1881: Paul Ehrlich and vital stain: living cell absorbs starch and dead cells do not - 1884: Hans Christian Gram and differential stain: separates microorganisms into groups Theory of Spontaneous Generation: hypothesis that living organisms can originate from nonliving matter. - 1668 Francesco Redi and flies with meat - 1822-1895 Louis Pasteur o Found that organisms found in putrefying materials originated from microorganisms present in the air and on the surfaces of the containers that held the materials. Cells are constantly being deposited on all objects and that they grow when conditions are favorable. o Aseptic technique: mechanism of handling equipment so that equipment stars sterile and bacteria that are being used do not become contaminated with other bacteria. (helps with transferring microbes) o Sterilization by heat  Killed all bacteria or other microorganisms in or on objects o Swan neck flask: countered the idea that boiling affected the air in the sealed flask so that it could no longer support spontaneous generation.  Nutrients could be heated to boiling and sterilized, but when cooled air was allowed to reenter but bends in the neck presented particulate matter from entering the main body of flask causing contamination.  Disproved spontaneous generation o Created vaccines for rabies, anthrax, and fowl cholera - 1843-1910 Robert Koch and germ theory of disease o proved that a specific microorganism causes a specific disease - Watson and Crick: proposed that the DNA molecule has a double helix chemical composition Chemotherapy - many chemicals were able to kill the disease, but the patient also died Microbial Physiology and Genetics - 1941 Beadle and Tatum: one gene one enzyme theory with Neurospora sp (fungi) o took x-rays of mold and found that genes direct the manufacture of proteins that control the basic metabolic functions o genes produce enzymes  Bacteriology-Bacteria  Virology- Viruses  Phycology- Algae  Mycology- Fungi Mold and Yeast  Protozoology –Protozoan 1  Parasitology- Parasites  Immunology- Immune system Chapter 2 Six Kingdoms of living forms - Plant, Animal, Fungi, Moneran, Protista, Archaea o Eukaryote: has nucleus containing DNA  Fungi-mold. yeast, slime mold  Protista  Algae-photosynthetic  Protozoan-not photosynthetic  Animal  Plants o Prokaryotic: DNA is held in the middle of the cell, not in a nucleus  Archaea: archaebacteria (< were believed to be the oldest form of a living thing)  Methanogenic, halophilic, thermophilic  Moneran-Eubacteria  Bacteria, bluegreen algae (Cyanobactera---perform photosynthesis), mycoplasma(do not have a cell wall), rickettsia and chlamydia Microscopy - light microscopes o Bright field or compound microscope  prokaryotes lack contrast with surrounding media. Have to stain bacteria to use o Fluorescent microscope  Uses UV or blue light and special dyes o Phase contrast microscope  Increases the contrast between the cell and the media without stain  Main advantage is in studying living cells o Dark field microscope  Greatest contrast between cell and media  Only the outlines of the organisms are seen - Electron Microscopes o Uses electrons instead of light and requires certain techniques  Transmission Electron Microscopy (TEM)  Thin sectioning: shows internal structure  Shadow casting  Negative staining (stains background)  Freeze etching o Sample is frozen rapidly and then fractured along natural planes of weakness to show its internal structure  Scanning Electron Microscopy (SEM) 2 - Cytoplasmic Content o Ribosomes  60% RNA and 40% protein  Sedimentation rate 70 S ( 30 S + 50 S )  Has a big subunit and a small subunit because of how it floats  S: Svedberg unit--unit of sedimentation (measured with centrifuge)  function - protein synthesis(make more protein) o Nucleoid  contains DNA (1 chromosome) that is highly folded, supercoiled circle.  contains Ca++ and Mg++  DNA has a (-) charge so Ca++ and Mg++ allow strands to come together - Capsule (Slime Layer or Glycocalyx) o biofilm or protective coating that allows bacteria to grow o a gel- like structure composed of complex polysaccharides, nitrogen containing compounds and polypeptides o varies in thickness, density, and adherence o Function:  prevent desiccation  resist phagocytosis  resist bacteriophages  aid in attachment o thick/sticky: capsule o thin/ slimy: slime layer o unknown: glycocalyx - Bacterial Endospores (“spore stain”) o Resistant to heat, drying, chemical disinfection, stains, radiation  Combination of all of these are able to kill spores o Ca++ and dipicolinic acid found in spores o Sporulation - when conditions become unfavorable  Bacterial cell protects DNA inside bacteria that holds spores 5  Endospores formed from cells in vegetative state o Germination- when favorable conditions return  Bacteria pops out of spore and is much bigger and is vegetative - Bacterial Flagella o Function – motility  Move like a propeller, clockwise or counter-clockwise o Types  Polar (monotrichous)  1 flagella  Amphitrichous  2 flagella on opposite ends  Lophotrichous  Several flagella all close together in a clump  Peritrichous  Several flagella spread evenly throughout bacteria o Amphi, Lopho, and Peritri can go side to side but if they want to go up or down they have to stop and reorient o Not all bacteria have flagella and those that do have different numbers and different arrangements o Helical structure composed of protein flagellin o Rotation of hook (protein) causes motion  - Bacterial movement o Chemotaxis (b)  Flagellar movement across a chemical gradient o Phototaxis (d)  Flagellar movement across a light gradient  Due to light 6 - Fimbrae and Pili o Fimbriae -Short straight filamentous protein structures on surface of cell  Solid proteins  Function- help organism stick o Pili- Short straight filamentous hollow protein structure on surface of cell  Purpose- allow DNA transfer between bacteria  Viruses can attach an infect through pili - Gas vesicle o Found in cyanobacteria  Uses sunlight (in photosynthesis) to produce O2 o Spindle shaped structure o Allows them to float o Composed only of protein  Doesn’t have membranes like other vesicles o Very rigid  Able to store gas because of this o 2 proteins  GvpA: pleasted sheet (folded)  Can stretch and contract  Size of gas vesicle is dependent on this protein  GvpC: perpendicular to GvpA - Inclusion Bodies o nuclear or cytoplasmic aggregates of stainable substances, usually proteins  typically represent sites of viral multiplication in a bacterium or a eukaryotic cell  usually consist of viral capsid proteins  Not all bacteria have them o Poly-B-hydroxybutyric acid (PHB) o Can be converted into plastic o Glycogen/starch o Polyphosphate o Sulfur o Magnetosomes Eukaryotic Cell o Structurally more complex than prokaryote  Membrane containing organelles: mitochondria, nucleus, golgi apparatus, etc o Has membrane enclosed organelles o Ribosomes: make proteins  Sedimentation rate 80S 7 - Flagella (long, not many)and Cilia(short, usually tons together) o Cilia and flagella are protein microtubule extensions of the plasma membrane  1. Aid in movement of simple organisms  9+2 configuration  9 tubules on outside  2 tubules in center (central microtubules)  basal body: bottom of flagella/cilia  doublets: 2 tubules connected to make each of the 9 tubules  center has two single tubules not connected - Nucleus o Nucleus is control center of the cell  Membrane bound (nuclear envelope)  Contains nucleolus, which synthesizes ribosomal RNA  DNA in chromosomes (DNA and proteins)  More than one chromosome per cell and different sizes o Nuclear pores: proteins and rRNA can go through the nucleus but DNA cannot leave nucleus. - Endoplasmic Reticulum 10 o consists of folded, branching and fusing, membranes tubules and sacs attached to the nucleus  Rough ER makes protein (contains ribosomes)  Smooth ER makes lipid (no ribosomes) o Golgi Apparatus:  membranous sacs associated with ER a. Processing and transport of proteins, lipids b. Synthesis and transport of polysaccharides 11 - Lysosomes o Lysosomes are Golgi-derived vesicles containing digestive enzymes  Used to digest bacteria  Used to digest worn out cell parts  Ex: mitochondria not working -> call parts used for something else  Causes the breakdown of the cell wall by cleaving the two amino sugars in the glycan layer of the peptidoglycan - Cell Division o Mitosis- exact identity and number of chromosomes retained  asexual reproduction (for unicellular organisms), growth, and maintenance and repair (multicellular organisms) o Meiosis-half number of chromosomes retained  is used for sexual reproduction  A reductional division resulting in haploid cells  Involves two sequential divisions resulting in four cells  Produces cells that are genetically different Chapter 17: Diversity of Eukaryotic Organisms - Uses 18S rRNA genes for phylogeny of eukaryotes - Relationship of 18S rRNA genes is much less strong for eukaryotes than 16S rRNA genes are for prokaryotes - Phylogenies have been constructed using other genes (i.e., tubulin, RNA polymerase, and ATPase) 12 o conidiospores  sexual reproduction (common) o basidiospores   Deuteromycetes - fungi imperfecti  No known sexual cycle  Mold and yeast o Examples: Histoplasma capsulatum,  Septate hyphae  Most Human pathogens  Biphasic or dimorphic o Fungal phase and yeast phase Protozoans - Classification was based on motility o Diplomonads and Parabasalids – flagellates o Euglenozoans – flagellates o Alveolates – ciliates, flagellates, apicomplexans o Stramenopiles – water molds, diatoms, and golden algae o Cercozoans and Radiolarians - threadlike pseudopodia o Amoebozoa- Amoeboid movement - Some protozoa produce cysts o Protect against the environment o Reproductive function o Means of transfer from one host to another - Parabasalids o Trichomonas vaginalis  STD o Contain a parabasal body o Lack mitochondria, but have hydrogenosomes(lack cristae and citric acid cycle enzymes) for anaerobic metabolism o Genomes lack introns - Diplomonads o Giardia intestinalis (Giardia lamblia)  Cause of Giardiasis, a common waterborne disease o Have two nuclei of equal size o Have mitosomes Euglenozoans - Unicellular flagellated eukaryotes - Have a crystalline rod in their flagella - Kinetoplastids o Trypanosoma brucei gambiense  Causes African sleeping sickness 15 o Named for the presence of the kinetoplast, a mass of DNA present in their single large mitochondrion o Live primarily in aquatic habitats feeding on bacteria - Euglenids o Euglena sp. o Nonpathogenic and phototrophic o Contain chloroplasts, can exist as heterotrophs o Can feed on bacteria by phagocytosis (consumes things) Alveolates - characterized by presence of alveoli which are sacs underneath the cytoplasmic membrane - Members are ciliates, dinoflagellates, and apicomplexans o Cilliates – organisms with cilia  Paramecium sp. , Balantidium coli o Dinoflagellates - Have two flagella with different insertion points on the cell  Pfiesteria piscicida < (red tide) o Apicomplexans- Obligate parasites of animals Apicomplexans (Sporozoan) - Non motile ; parasitic o Plasmodium sp. -Malaria o Toxoplasma gondii –Toxoplasmosis (1/2 population has it) o Eimeria sp. - Coccidiosis o Cryptosporidium sp.  Disease:  Cryptosporidiosisasis  Mostly asymptomatic, mild diarrhea, stomach ache, abdominal tenderness  Etiology  Oocysts of Cryptosporidium  Epidemiology  Transmitted by oocysts to food and water  Found in intestinal tract of man, and other mammals  Control  Proper hygiene  Municipal sanitation Strameopiles - Oomycetes, diatoms, golden algae, and brown algae - Oomycetes o water molds based on their filamentous growth and the presence of coenocytic hyphae - Diatoms o Over 100,000 species of diatoms o Freshwater and marine habitats 16 o Cell walls are made of silica and are called frustules - Golden algae o Chrysophyta (chrysophytes) o Most are unicellular, however, some are colonial o Golden algae are named because of their golden-brown color o photosynthetic Industrial microbiology: involves the use of microorganisms to make products such as antibiotics, vaccines, steroids, alcohols, vitamins, amino acids, and enzymes. Streptococcis pneumonia contains a capsule Bacillus subtilis : spore-forming bacteria Streptomycin: Waxman discovered it 17