Microbiology test 1 Galen college of nursing Louisville, KY – Flashcards
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Importance of microorganisms r/t the biosphere?
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Essential for cycling C, N, O; food chains- at the base of all good chains.
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.. R/t endosymbiotic relationships?
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Present in our intestines and aid digestion.
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.. R/t foods production?
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Making bread, cheese, beer, and other fermented foods.
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.. R/t disease?
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Microbial infections, viral infections.
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A pathogenic microbe is?
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Disease causing?
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Explain the binomial nomenclature system.
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Q organism has 2 names: genus and specific epithet. Genus is cap. The specific epithet is lowercase. Both are italicized or underlined. Ex: Escherichia coli.
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What are the 3 domains?
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Eubacteria Archaea Eukarya
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Eubacteria?
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(true bacteria)-prokaryotic, unicellular, peptidoglycan cell wall.
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Archaea?
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prokaryotic, unicellular, no peptidoglycan in cell wall, unusual metabolism.
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Eukarya?
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- eukaryotic (protista- protozoa/algae, fungi- yeast, molds and mushrooms, animals and plants), unicellular or multicellular.
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Explain bacteria.
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Prokaryotes, has peptidoglycan cell wall, various energy sources: organic chemicals, inorganic chemicals, or photosynthesis.
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Explain archaea.
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Prokaryotes, no peptidoglycan, love in extreme environments, unusual metabolisms. Includes methanogenes, extreme halophiles, extreme thermophiles.
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Fungi?
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Eukaryotes, chitin cell walls, use organic chemicals for energy, molds and mushrooms are multicellular, yeasts are unicellular.
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Protozoa?
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Eukaryotes, absorb or invest organic chemicals, motile via pseudopods, cilia, or flagella.
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Algae?
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Eukaryotes, photosynthesis for energy, produce O2 and organic compounds.
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Viruses?
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Acellular (not considered living), surrounded by a protein coat which may be enclosed in a lupus envelope, can only replicate when in a loving host.
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What are helminths?
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Eukaryotes, multicellular, parasitic Flatworms and roundworms.
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What is Linnaeus known best for establishing?
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The binomial nomenclature system.
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What is Robert Hooke known for?
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Reported that living things are composed of little boxes, or cells.
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Anton van Leeuwenhoek?
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Described live microorganisms as "animalcules"
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Louis Pasteur?
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Used curved neck flasks and boiled material in the flasks, showed microbes are responsible for fermentation, and demonstrated pasteurization..
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Lister (a surgeon)?
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Used a chemical disinfectant to prevent surgical wound infections.
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Koch?
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Provided experimental steps, kochs postulates, too prove that a specific microbe causes a specific disease.
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Jenner?
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Discovered the first vaccination, smallpox.
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Ehrlich?
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Developed salavarsan, too treat syphilis.
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Fleming?
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Discovered the 1st antibiotic, penicillin.
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Microbial ecology?
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Bacteria recycle carbon, nutrients, sulfur, and phosphorus that can be used by plants and animals.
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Bioremediation?
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Bacteria degrade organic matter in sewage; bacteria the grade or detoxify pollutants such as oil and Mercury.
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Biotechnology?
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The use of microbes to produce foods and chemicals, is centuries old.
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Recombinant DNA technology?
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A new technique for biotechnology, enables bacteria and fungi to produce a variety of proteins, including enzymes. Handb used for gene therapy and genetically modified bacteria to protect crops from insects and freezing.
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Normal microbiota?
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Microbes normally present in and on the human body, prevent growth of pathogens, produce growth factors such as folic acid and vitamin K.
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Resistance?
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Ability of the body to ward off disease. Factors include skin, stomach acid, and antimicrobial chemicals and specific immunity.
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What are biofilms?
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Microbes attach to solid surfaces and grow into masses. Grow on rocks, pipes, teeth, and medical implants.
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Emerging infectious diseases?
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New diseases and diseases increasing in incidence. Overcomes the host resistance, disease results. Example avian influenza A.
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Avian influenza A?
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This can be a major problem if it is ever able to pass from human to human. Currently is only found primarily in waterfowl and poultry. Human to human transmission has not occurred yet.
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Other infectious diseases MRSA?
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Methicillin-resistant Staphylococcus aureus.
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What is the leading cause of diarrhea worldwide?
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Escherichia coli
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Other current infectious diseases?
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Ebola Hemorrhagic Fever, Cryptosporidiosis, AIDS.
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Centimeter =?
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10^-2 (cm)
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Millimeter=?
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10^-3 (mm)
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Micrometer=?
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10^-6
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Nanometer=?
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10^-9
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If a microbe is measures 10 micrometers in length, how long is it in nanometers?
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10,000 nm?
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A RBC is about what size?
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5 micrometers
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Light microscopy?
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Can be compound, darkfield, phase contrast, differential interference contrast, fluorescence, or confocal.
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What is a compound microscope?
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In this kind of microscope, the image from the objective lens is magnified again by the ocular lens.
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What is total magnification?
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Objective lens times ocular lens
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Refraction?
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Is the bending of light as it passes from 1 medium into another. Example air and glass lens
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Refractive index?
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A measure of how much a substance slows the velocity of light. It's a measure of the light bending ability of a medium. Immersion oil is used to keep light from bending too much so that it may be seen.
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Resolution?
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Is clarity, the ability to see two objects as separate and distinct.
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Parfocal?
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The image stays in focus when changing to higher power objective.
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Brightfield illumination?
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Dark objects are visible against a bright background. Stains are used.
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Dark field illumination?
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Light objects are visible against a dark background. Useful to see live organisms because no stain is used.
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Fluorescence microscopy?
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Uses UV light, fluorescent substances absorb UV light and emit visible light, cells may be stained with fluorescent dyes known as fluorochromes.
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Confocal microscopy?
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cells are stained with fluorescent dyes, blue light is used to excite the dyes, the light illuminates to produce a three-dimensional image.
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Two photon microscopy?
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Cells are stained with fluorescent dyes, red light are used to excite the dyes. Used to study the surface of cells.
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Scanning acoustic microscopy (SAM)?
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Measures sound waves that are reflected back from an object. Used to study cells attached to it.
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Transmission electron microscopy (TEM)?
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Ultrathin sections of specimens, may be stained with heavy metal salts, uses electrons instead of light.
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Scanning electron microscopy (SEM)?
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An electron gun produces a beam of electrons that scans the surface of the whole specimen. Used to see the surface.
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What is a smear ?
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A thin film of a solution of microbes on a slide. Is usually fixed to attach the microbes to the slide in to kill the microbes., stains the background and not the cell structures.
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What are some basic dyes?
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Methylene blue, basic fuchsin, crystal violet, safranin, and malachite green.
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Simple stains?
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Uses a single basic died. A mordant may be used to hold the stain or coat the specimen to enlarge it.
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Gram stain?
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Classifies bacteria into positive or negative. Positive bacteria tend to be killed by penicillin and detergent. They have a thick peptidoglycan layer. Gram negative are more resistant to antibiotics and have a thinner layer.
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Procedure for a Gram stain?
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Crystal violet is the primary stain, iodine is added acting as a mordant causing the cells to adhere to the crystal violet more strongly, ethanol is used to decolorize (+ cells won't lose their color), safranin is the counter stain (adds color back to the - cells).
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What do Gram negative and Gram positive cells look like?
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Negative, rod shaped. Positive, cocci.
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Acid fast stain?
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They contain mycolic acids a waxy substance in their cell walls the waxy substance is not decolorized by acid alcohol. They are important pathogens like leprosy and TB.
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Acid fast staining procedure?
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Primary stain- carbolfuchsin, decolorizer-acid alcohol, counterstain-methylene blue.
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Results of acid fast test?
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Primary stain- both will be red. Decolorizer - acid-fast will be red, non acid fast will be colorless. Counterstain- acid-fast will be red and non acid fast will be blue.
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What are special stains used for?
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Capsule stain, endospore stain, flagella stain.
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Endospore stain?
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Requires heat to drive the malachite green stain into the endospore. Then cold, decolorized buy a water rents, counter stained with safranin. Yield green endospores and pink cells.
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Why do we need to know about endospore identification?
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Endospores are heat, drought resistant structures formed by some bacteria as an adaptation for survival in unfavorable conditions. Its valuable and identification for presence or absence of shape.
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Flagella staining?
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A mordant is used on flagella. Carbolfuchsin simple stain.
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Some differences between prokaryotic and eukaryotic cells?
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Prokaryotic cells have no nuclear membrane or nucleoli, no organelles, two protein building blocks for flood Gela, a capsule or slime layer, peptidoglycan for the cell wall, plasma membrane does not have carbohydrates and lacks sterols, divides by binary fission, and transfer of DNA only for sexual recombination.
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Eukaryotic cells continued
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True nucleus consisting of nuclear membrane and nucleoli, membrane enclosed organelles present ( lysosomes, Golgi complex, endoplasmic reticulum, mitochondria, and chloroplasts), flagella consists of multiple microtubles and is complex, cell wall is chemically simple and include cellulose and chitin, sterols and carbohydrates serve as receptors in plasma membrane, cytoskeleton receta plasmid streaming present, multiple linear chromosomes with histones in the DNA, and divides by mitosis.
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Prokaryote comes from the Greek word for?
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Pre nucleus.
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Eukaryote comes from the Greek words for?
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True nucleus.
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Describe prokaryote chromosome and membrane status.
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One circular chromosome and does not have a membrane.
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Prokaryotes knowledge
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No histones no organelles, bacteria have peptidoglycan cell walls, Archara have pseudomeuein (false) cell walls, and they all divide by binary fission (one split).
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Eukaryote knowledge
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Paired chromosomes in a nuclear membrane, histones, organelles, polysaccharide cell walls, divide by mitosis or meiosis.
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How do prokaryotes differ from eukaryotes.?
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Difference in size and lack of internal membrane systems, prokaryotes divide into bacteria and archaea, bacteria are divided into two groups based on the Gram stain reaction.
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Cocci shape
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Spherical, round
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Bacilli shape
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Rods. Coccobacilli-Betty short rods. Vibrios- comma shaped
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Spirilla shape
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Rigid helices
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Spirochete shape
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Flexible helices
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Mycelium shape
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Network of long, multinucleate filaments, mostly eukaryotic
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Pleomorphic
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Vary in shape.
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Bacterial arrangements
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Pairs :diplococci, diplobacilli (diplo) Clusters:staphylococci (staphylo) Chains :streptococci, streptobacilli (strepto)
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What is/purpose of glycocalyx?
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Is outside cell wall and sticky. capsule: neatly organized which helps evade mucocytosis, slime layer: unorganized and loose. Capsules prevent phagocytosis and is significantly larger that cell.
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Flagella?
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outside so wall, made of chains of flagellin, attached to a protein hook, anchored to the wall and membrane by the basal body.
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What does fimriae do for the cell?
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Allows attachment
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What is pili for?
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Usually there is only one or two, facilitates transfer of DNA from one cell to another, gliding motility or twitching motility. Neither works great but it does help get the job done
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Purpose of peptidoglycan cell walls in bacteria?
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Prevents osmotic lysis.
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Gram positive cell wall
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Has thick peptidoglycan, teichoic acids (which is only found in Gram positive cells), and are more simple. Has 2 ring basal body in flagella, disrupted by lysozymes, PENICILLIN SENSITIVE.
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Gram negative cell walls.
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Thin peptidoglycan, outer membrane, periplasmic space, and is more complex. 4 ring basal body in flagella, endotoxin, tetracycline sensitive.
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Acid fast cell walls
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Is atypical. Similar to gram + cells walls, waxy lipid (mycolic acid) bound to peptidoglycan.
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Mycoplasmas and archaea atypical cell walls
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Mycoplasmas lack cell walls, has sterols in plasma membrane. Archaea are wall-less or walls of pseudomurein (false)
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Simple diffusion?
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Movement of a Salyut from an area of high concentration to an area of low concentration
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Facilitated diffusion?
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Salyut combines with the transporter protein in the membrane. Needs to be specific for receptor to bind to glucose thus will change shape and allow solute to enter cell.
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Osmosis?
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The movement of water across a selectively permeable membrane from an area of high water to an area of low water concentration.
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Osmotic pressure?
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The pressure needed to stop the movement of water across the membrane.
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Active transport?
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Requires a transporter protein and ATP. Can go against gradient.
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Eukaryotic flagella and cilia
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Forms microtubles. Distinctly different from prokaryotic flagella and cilia.
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Eukaryotic Glycocalyx
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Carbohydrates extending from animal plasma membrane. Bonded to proteins and lipids in membrane
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Similarities of plasma membrane prokaryotes versus eukaryotes?
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Phospholipid bilayer, peripheral proteins, integral protein, trans membrane proteins.
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Differences in plasma membrane prokaryotes versus eukaryotes?
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eukaryote cell membranes contain cholesterol and carbs and. endocytosis. most prokaryotes lack cholesterol which makes the cell membrane less rigid
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Metabolism is?
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The total of all chemical reactions in the cell and is divided into two parts catabolism and anabolism.
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Anabolism?
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The synthesis of complex organic molecules from simpler ones, requires ATP.
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Catabolism?
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Breakdown of complex organic compounds into simple ones (AB-->A+B), generally hydrolysis which use water to break chemical bonds, release ATP. provide energy for anabolic reactions.
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Describe enzymes.
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Encoded by genes, lower amount of ATP needed for activation, reactions would not take place at the temperature of life. Enzymes assist this process and don't get used up in this process.
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Oxidoreductase?
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Oxidative-reduction reactions.
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Transferase?
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Transfer functional groups.
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Hydrolase?
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Hydrolysis
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Lyase?
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Removal of atoms without hydrolysis.
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Isomerase?
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Rearrangement of atoms.
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Ligase?
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Linking of molecules; uses ATP.
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What factors influence enzyme activity?
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High temperature and extremes of pH denature (unfold) proteins, inhibitors (competitive and noncompetitive, aka allosteric, inhibition.
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Denatured proteins..
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Unfolding of protein making it not functional. This can be permanent or temporary.
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Competitive inhibition
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Inhibitor competes with the normal substrate for the active sites of enzymes
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Non-competitive or allosteric inhibition
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Inhibitor binds at a different site than the substrate (allosteric site). Changes shape of enzyme.
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Oxidation reduction reactions
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Oxidation- removal of electrons, reduction- gain of electrons, redox reactions- an oxidation reaction paired with a reduction reaction.
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Oxidation reduction reactions are associated with what type of atoms?
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Hydrogen atoms. Biological oxidations are often dehydrogenations.
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ATP is generated by the phosphorylation of what?
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ADP.
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What is oxidative phosphorylation?
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Energy released from transfer of electrons, oxidation, of one compound to another, reduction, is used to generate ATP in the electron transport chain.
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What is photo phosphorylation?
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Light causes chlorophyll to give up electrons. Energy released from oxidation of chlorophyll is used to generate ATP.
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What is phototrophy?
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Photosynthesis. Energy from light trapped and converted to chemical energy. A two-part process, light reactions and dark reactions.
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Light reactions?
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Light energy is converted to chemical energy. Light absorbing pigments are excited and transfer electrons and protons. Electrons are energized and used to make ATP and NADPH.
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Dark reaction?
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Is a light independent reaction. Calvin cycle is carbon fixation.
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What is oxygenic photosynthesis?
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eukaryotes (in chloroplasts) and cyanobacteria. Uses co2 as C source, produces O2 (use h2o). Chlorophyll is the photosynthetic pigment. creates ATP and NADPH. have photosystems 1&2.
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Anoxygenic photosynthesis.
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Phototrophic green and phototrophic purple bacteria and Helio bacteria. Use organic C or co2, creates ATP only, only have photosystem 1.
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In cellular respiration ATP is generated by what?
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By oxidative phosphorylation. Involves use of an electron transport chain
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Fermentation (anaerobic)
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In the absence of o2 get energy only from glycolysis. No citric acid cycle or electron transport system involved.
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Examples of fermentation products
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Pyruvic acid (pyruvate) -->lactic acid and pyruvic acid -->acetaldehyde-->ethanol. Named according to what they make. Very little ATP is made by fermentation.
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Carbohydrate catabolism
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Aerobic respiration. Breakdown of carbohydrates to release energy by glycolysis, by fate of pyruvate, Krebs cycle, or electron transport chain.
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What does glycolysis produce in carbohydrate catabolism?
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The oxidation of glucose to pyruvic acid produces ATP and NADH.
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What does fate of pyruvate produced in both carbohydrate catabolism and fermentation?
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Aerobic, pyruvate --> acetylCoA. Anaerobic, pyruvate-> fermentation then lactic acid.
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For each Electron transport chain with carbohydrate catabolism (aerobic respiration)
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Most of ATP is produced this way
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Summary of glycolysis
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Start with one 6 carbon molecule of glucose and becomes 2 pyruvate (indirectly feeds citric acid cycle), 2 net ATP (cellular energy), 2 NADH (feeds electron transport chain)
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Krebs cycle
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Oxidation of acetylCoA produces NADH and FADH2.
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Summary of Krebs cycle (TCA cycle)
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For each acetylCoA oxidized, TCA cycle generates: 2 CO2, 3 NADH, 1 FADH2, 1 GTP. There are 2 turns off the TCA cycle per 1 molecule of glucose.
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Electron transport chain
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Series of electron carriers that operate together to transfer electrons to an electron acceptor. 1 glucose yields about 38 ATP from glycolysis TCA and electron transport.
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Electron transport chain continued
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Carrier molecules are oxidized and reduced as electrons are passed down the chain. Energy released can be used to produce ATP by chemiosmosis.
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Oxidative phosphorylation chemiosmotic theory
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ATP is synthesized as the result of electron transport driven by the oxidation of a chemical energy source. Electron transport system creates the proton motive force (a high concentration of protons on 1 side of the membrane)
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A summary of respiration
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Aerobic- 38 ATP, final electron acceptor in transport chain is O2 (carb breakdown). Anaerobic-final electron acceptor in transport chain is not O2 (glycolysis), yields less energy than aerobic respiration.
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Fermentation
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glycolysis with or without 02. Produces alcoholic beverages or acidic dairy. Releases energy from oxidation of organic molecules, does not require o2, does not use the Krebs cycle or ETC, users organic molecule as the final electron acceptor.
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Alcohol and lactic acid fermentation
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Alcohol fermentation produces ethanol and co2 lactic acid fermentation produces lactic acid
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What are biochemical tests used to identify?
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To identify bacteria.
