Micro Test 1: Lectures 1-7, 11 – Flashcards

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question
Early Microbiology attributed disease to:
answer

 

Evil spirits 
Bad Blood 
Bad air

     

    question
    Anton Van Leeuwenhoek
    answer

     

    invented first microscope
    "Animalcules"

       

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      Abiogenesis
      answer

       

      Live from Non-life
      AKA: Spontaneous Generation

         

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        Louis Pasteur
        answer

         

        Pasteurization of wine/milk/juice
         Vaccines: Cholera, rabies & anthrax(fail) 
        Associated with Koch germ theory

           

          question
          Robert Koch
          answer

           

          ID cause of anthrax; B. anthracis
          Koch's postulates; criteria to ID a disease from a pathogen
          Developed Pure culture technique and staining techniques

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            question
            Koch Postulates
            answer

            The cause of the disease must be:

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            1. found in all cases of the disease examined
            2. prepared and maintained in a pure culture
            3. produce originial infection after, even after several generations
            4. retrievable from an inoculated animal and cultured again

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            Ignaz Semmelweis
            answer
            Handwashing
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            Joseph Lister surgical technique

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            Edward Genner

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            Alexander Fleming

            answer

            Aseptic technique using phenol on surgical wounds


            Cowpox used for protection against small pox


            Pencillin discovery (1928)

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            Why Classify bacteria?;
            answer

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            Communication
            Evolutionary Relationships
            Illustration of diversity

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              question
              Three Domain System
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              Archae ; ; ; ; ; ; ;Eukaryota

              ;; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;;;;; ;; ;;;;;;

              ;; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;;;;

              Bacteria ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;

              ;; ; ;;;;;;;;;;;;;;;;;

              ;; ; ;; ;; ; ; ; ;Archae and Eukaryota more closely related

              question
              Naming species
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              Genus species or Genus species
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              Bacteria storing
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              Lyophilized (freeze-dried)

              Frozen at -80;C

              Liquid N2 (-196;C) for long term

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              Taxonomic Scheme

              Classical

              answer

              **Requires growth of organism ; observation used to classify microorgansims**

              structure/morphology

              biochemical/physiological

              cell surface

              GC composition

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              structure/morphology
              answer

              physical characteristics:;

              shape/size of colony/cell

              arrangement

              external features

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              question
              Biochemical/Physiological
              answer

              physiological characteristics:

              growth factors

              metabolic end products

              antibiotic sensitivites

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              Cell surface
              answer

              Serological; ex. capsule

              Phage typing (detecting single strains of bacteria)

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              Guanine-Cytosine content
              answer

              Determine percent GC content by:

              melting DNA; (higher GC content=higher mp)

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              Genetic Scheme
              answer

              Phylogeny: changes in DNA gene sequence over time; evolution

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              *Not always necessary to culture organism

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              Guidelines of which gene is used
              answer

              Universal. All bacteria should have the gene

              Identical function

              Easy to work with

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              16S or 23S in prokaryotes

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              Three methods of Genetic Scheming
              answer

              Nucleic Acid Hybridization

              Nucleic Acid Sequencing

              DNA fingerprinting (not used as much)

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              Nucleic Acid Hybridization
              answer

              Flourescent tagged probes of complimentary DNA that hybridize with the complimentary rRNA of the bacteria.

              Viewed with a Flouresence Microscope

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              Nucleic Acid Sequencing
              answer

              Extract gene for interest (rRNA)

              Polymerase chain reaction (amplify)

              use computer to align sequences (compares squence to known organisms)

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              Endosymbiotic Hypothesis
              answer

              Bacterial endosymbiont of eukaryote lost ability to live independently

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              DNA/Ribosomes similar to bacteria

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              Common bacteria used in lab
              answer

              Gram Positive

              ;cocci: ex. S. aureus ;

              ;;streptococcus ;;;

              ;;staphylococcus ;;;

              ;bacilli

              Gram Negative

              ;Bacilli

              ;;Lactose + (E. coli;)

              ;;Lactose -


              question
              Gram positive stain
              answer

              Thick peptidoglycan layer

              2 membranes

              polysaccharide capsule

              flagella: 2 support rings

              stains: dark purple

              S-layer attached to petidoglycan if present

              sporulate

              teichoic acid/lipoids form lipoteichoic acid;

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              Gram Negative
              answer

              Cytoplasmic Membrane

              Thin peptidoglycan layer

              stains: light pink

              porins (pores)

              flagella (4 support rings)

              s-layer attached directly to outer layer

              do not sporulate

              Lipopolysaccharide outer layer

              question
              Three Domain Characteristics
              answer

              Archae: single-celled, no nucleus/organelles

              Bacteria: large single-celled, prokaryotic


              Eukaryota: multicellular


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              question
              Magnification vs. Resolution
              answer

              Magnification: how big

              Resolution: distinguish fine detail (smaller wave length

              question
              Light Microscopy
              answer

              View living specimens at 1000x-1500x

              Types:;

              Brightfield: specimen is dark, field is light (heat-fixed and stained specimens)

              Phase Contrast: Best for unstained, living specimens

              Flourescent: uses UV light (smaller wave length=greater resolution)

              question

              Structure comparisons

              Prokaryote vs. Eukaryote

              answer

              Cytoplasmic membrane: BOTH

              Membrane-bound nucleus: Eukaryote

              Ribosomes: prokaryote (70S)/ eukaryote (80S)

              Cell Wall: petidoglycan(P)/ cellulose(E)

              Internal membrane-bound organelles: Eukaryote

              Flagella: flagellin(P)/ Microtubules(E)

              Cytoskeleton: **Actin(P);/ eukaryotes

              Cell Size: .3-3 microns(P)/ ;3 microns(E)

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              Bacterial Cell Structures
              answer

              Cocci

              Bacilli

              Spirilla

              Stalked

              Sheathed

              Pleomorphic

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              External Cell Structure;Types
              answer

              Capsule: slime

              S-layer: protein surface layer; protection

              pili: adhesion/conjugation

              flagella: motility

              chemotaxis: ability to move toward attractant (positive) or away from repellent (negative)

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              Capsule, Glycolax or slime
              answer

              protection

              hydrated polysaccharide or polypetide

              can be thicker than bacteria

              Creates immune response: antigenic reaction (ex. K-antigen)

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              Cell Envelope

              Peptidoglycan

              answer

              NAG-NAM structural component

              functions: maintain cell shape, resist osmotic stress

              Contain Teichoic Acid in Gram POSITIVE

              Lysozyme breaks down PG

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              NAG-NAM
              answer

              dissacharides bonded in rows/columns by polypeptides (sugars linked with proteins)

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              Pentaglycine bridge is Gram positive

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              Gram Negative Cell Wall
              answer

              2 layers:

              1) Thin layer of Peptido Glycan

              2) Surrounded by outer membrane

              linked by lipoproteins

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              Cell Membrane Properties
              answer

              membrane fluidity: short tails and double bonds (enables growth at lower temps)

              ;

              lack of fluidity (growth at higher temps)

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              Cytoplasmic membrane Function
              answer

              distinguishes self from environment

              site of ATP synthesis

              entry/exit control

              synthesis site for cell wall and surface components

              maintains proton motive force

              question
              Membrane Protein Function
              answer

              Proteins*20 amino acids connected by peptide bonds that fold into 3D structures*

              synthesis of cell wall components

              respiratory enzyme/ATP synthesis

              Transport across membrane

              question

              Protein Transport functions

              diffusion, facilitated diffusion, active transport, group translocation, secretion

              answer

              Diffusion: molecules move freely energy independent (hi;low)

              Facilitated Diffusion: carrier protein, requires concentration gradient (hi;low)

              Active Transport: works against concentration gradient, requires energy (ATP;ADP)

              Group Translocation: Phosphorolation (molecule chemically modified by phospho group), requires energy

              Secretion: multiple pathways

              question
              Are all Cellular Membranes the same?
              answer

              No.

              Phosopholipids: fatty acid composition, molecule attached to phosphate

              ;

              Differences used for classification

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              Nucleoid
              answer

              one circular chromosome in the;cytoplasm containing supercoiled DNA that is not membrane bound, additional DNA present as plasmids

              ;

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              Endospores (spores)
              answer

              Gram positive

              most resistant biological structure known

              Resting Stage; non reproductive

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              Flagella Types
              answer

              Polar: one flagella at one end of rod

              Bipolar: 2 flagella, on opposite ends

              Peritrichous: 4 flagella

              Lophotrichous: multiple flagella at one end

              *H-antigens

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              Cell Membrane Structure
              answer

              Phospholipids: polar head, nonpolar tail

              Amphiphatic: assembles into bilayers

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              Archael Membranes

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              answer

              No peptidoglycan

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              question

              Cytoplasm

              ;

              answer

              rudimentary cytoskeleton

              contains ribosomes

              question
              DNA replication
              answer

              semiconservative: each strand is a template for DNA

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              Initiation

              Elongation

              Termination

              question

              DNA replication (E. coli):

              Initiation

              answer

              Origin: ori;C (Adenine/Thymine rich)


              DnaA (initiator protein) binds and unwinds DNA at;ori C

              uses energy (ATP;ADP), forms replication bubble


              Helicase seperates unwound DNA into leading strand (3'→5') and lagging strand (5'→3')

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              question
              Important Elongation Polymerases
              answer

              DNA Pol I:

              reads fragments, replaces RNA nucleotides with DNA nucleotides


              DNA Pol III:

              Needs DNA template, Nucleotides, Primer

              question

              DNA replication

              Elongation

              answer

              Template strand (leading) always 3'-5'

              DNA pol III adds DNA on template strand in 5'-3' direction following RNA pol

              Okazaki fragments synthesize short pieces in the 5'-3' direction on lagging strand

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              Elongation cont'd
              answer

              DNA pol III falls off

              DNA pol I cuts of RNA nucleotides and replaces with DNA nucleotides

              Finally DNA ligase seals gaps

              question

              DNA replication

              Termination

              answer

              2 ways:

              Tus protein recognize ter sites

               

              Bacteria have a cyclic chromosome

              question
              Post-Replication Events
              answer

              DNA is methylated (protection): masks DNA to not destroy good DNA

               

              Methylation proteins recognize new strand (unmethylated) and old strand (methylated) and repairs errors

               

               

               

               

              question
              Plasmids
              answer

              *DNA not located on the chromosome

              replicates like DNA with pol, but on smaller level

               

               

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              Replisome
              answer
              Starts new round of replication to speed the replication process
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              Replication Summary
              answer

              Must be rapid and efficient

              Semiconservative

              DNA synthesis occurs in the 5'-3' direction

              Methylation protects/aids mutation recognition

              Multiple rounds of replication 

              question
              Plasmids
              answer

              Conjugation: bacterial sex; plasmids copied and transferred to another bacterium by sex pilus

              Selective advantage: Can spread genes 

              Types: 

              transmittance: F plasmids, fertility

              Antibiotic resistance: R plasmids

              Xenobiotic degradation: oil eaters

              Virulent

               

              question
              Plasmids cont'd
              answer

              Plasmids can be isolated and studied

              At higher temperatures, plasmids can be 'cured' from the organism, then see if the trait is lost

              Curing: growing bacteria at a higher temperature so it throws plasmid out because it's not necessary

               

               

               

              question
              Polymerase Chain Reaction (PCR)
              answer

              Amplifies specific regions of DNA

              in vitro (out of cell) replication of target DNA

              Needs: DNA, Taq polymerase, dNTP, DNA primers

              1) Heating: Melt H-bonds

              2) Annealing: primers find complimentary bases

              3) Elongation: DNA polymerase

              question
              Recombination Types
              answer

              Recombination: trade chromosomes

              Homologous Recombination: Rec proteins help incorporate new DNA

              Non-Homologous Recombination: rare in bacteria, 2 random ends of DNA glued by ligase

              question
              Transpons
              answer

              Mobile element or "jumping gene"

              Jumps to a different place on the chromosome and copies itself

              Plasmids can spread with transpons

              question
              Types of Media
              answer

              Solid/Liquid

              defined media: uses pure chemicals in known concentrations

              complex media: ingredients present, but not chemically defined

              question
              Classification of Media
              answer

              General Purpose: complex, nutrient agar/broth; general growth

              Differentiation: blood agar; bacteria lyse RBCs

              Selective: MacConkey agar; selective for Gram negative, first step in ID of bacteria

              Enrichment: contains components that promote growth; *defined medium

               

              question
              Growth Curve
              answer

              X-axis: Time

              Y-axis: log #of visible cells

              phase 1: lag phase

              Phase 2: log phase (exponential phase)

              Phase 3: stationary phase

              Phase 4: Death phase

              question
              Nutrient Limitation Adaptation Strategies
              answer

              *organisms in nature are usually stressed

              Dormacy: spore formation in bacteria

              Reproduction: spore reproduction in molds

              Habitat Selection: most important (food!)

              Alter Metabolism: shut down non-essential proteins, induce proteins that aquire nutrients

              Adhesion

               

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              Metabolism
              answer
              Chemical reactions occuring within an organism
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              Catabolism
              answer

              Metabolic break down

              **Releases energy**

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              Anabolism
              answer

              Biosynthesis: Synthesis of necessary cell components for growth; building up

              **Requires energy**

              question
              Metabolism is tightly controlled
              answer

              Specific enzymes and Regulated enzymes

              Nutrients, Energy & Reducing Power: Required for survival

              Metabolic energy is stored as membrane potential (ATP)

              Reducing power stored as NADH or FADH2

              question

              Polymers→Monomer→End products

              (building blocks)

              answer

              polymers are insoluble and broken down by secreted enzymes then the monomers are transported by active transport/group location

               

              eg. Cellulose (insoluble) → Cellubiose (soluble)→ Glucose (soluble)

              question
              Monomers
              answer

              Once transported inside the cell, they are burned (catabolic) and captured as ATP, NADH, FADH

               

              question
              Monomer Pathways
              answer

              Glycolysis: catabolic reax, break down glucose and stored; glucose in→pyruvate out

              Entner Douderoff: Catabolic reax; glucose→ATP, not as effective

              Pentose Phosphate: Generates Ribose; used for DNA/RNA

              Kreb's cycle: central hub

              substrate level phosphorylation: catabolic; coupled directly to ATP production

              question
              Respiration
              answer

              Uses electron transport chain (ETC)

              often implies aerobic catabolism; **not always (anaerobic respiration)

              question
              Biosynthesis of Proteins
              answer

              ;

              Polymers formed from Monomers

              Amino Acids;; Proteins

              (Transcription)

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