Bio 2051 – Microbiology – Flashcards
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| 1. Cytoplasm 2. Cytoplasmic Membrane 3. Nucleus or nucleid 1. Eukaryotic has nucleus prokaryote has nucleoid 4. ribosomes- site of protein synthesis in eukaryotes and is also found in prokaryotes 5. Cell Wall - found in plants & most prokaryotes; not in animals |
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| What are the basic cellular structures? |
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| Algae (chlorophyll), fungi, protozoa, plants, animals |
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| What are some Eukaryotes? |
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| Prokaryote |
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| • Simpler internal structure • lack membrane bound organelles • has 2 domains: Bacteria & Archaea |
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| Eukaryotic |
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| • larger & more complex • __membrane enclosed organelles__ (nucleus, chloroplast, mitochondria, etc) |
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| Viruses |
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| • Reproduce only inside a host cell |
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| HIV virus, Rhinoviruses (colds) |
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| What are some examples of viruses? |
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| rabies |
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| The virus Rhabdovirus causes what? |
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| •Cytoplasm surrounded by envelope o Cytoplasm contains DNA in nucleoid • Envelope has lipid membrane boundary oPlus structural cell wall |
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| What does the bacterial cell consist of? |
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| Cytoplasmic membrane |
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| "fluid” selective permeability barrier made of phospholipids & proteins that form a bilayer with hydrophilic exteriors & a hydrophobic interior |
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| Phospholipid bilayer |
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| The Cytoplasmic membrane is also known as what? |
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| leaflet |
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| Each layer of the CM is called what? |
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1. Hydrophilic heads 2. Hydrophobic tails |
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| 1. group faces cytoplasm or periplasm 2. fatty acids line up inside membrane |
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| phospholipid |
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| ester-linkage links glycerol to fatty acid to form what? |
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| very small UNcharged particles |
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| What can easily cross through the selectively permeable CM |
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| integral membrane protein |
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| spans the width of the CM |
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| peripheral membrane proteins |
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| These are bound to the surfaces of the CM |
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| Permeability barrier |
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| Prevents leakage of cytoplasmic metabolites into environment |
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| Permeability barrier structural support Energy conservation |
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| The CM functions as what? |
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| Cytoplasmic membrane |
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| Where does respiration occur in prokaryotes? |
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| mitochondria |
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| Where does respiration occurr in eukaryotes? |
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| cytoplasmic membrane |
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| where do photosynthetic prokaryotes carry out photosynthesis? |
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| chloroplast |
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| what do eukaryotes have in order to carry out photosynthesis? |
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| cholesterol |
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| What do eukaryotes use in order to reinforce membranes? |
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| Hopanoids |
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| What do bacteria have in order to reinforce their membranes? |
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| Terpenoids |
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| What do Archae have in order to reinforce their membranes in high temp and low pH? |
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| Peptidoglycan (a porous cage-like structure) |
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| What is the bacteria cell wall (sacculus) composed of? |
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| Peptidoglycan |
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| ? sugar chains wrapped in circles around cell • “glyco” = “sweet” ? Sugar chains linked to each other by short polymers of amino acids • amino acid = “peptide” |
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| N-acetylglucosamine (NAG) N-acetylmurmaic acid (NAM) |
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| What two sugars make up the backbone of Peptidoglycan? |
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| Crosslinks (short chains of acids) |
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| Chains of Peptidoglycan are held together by _________ between N-acetylmuramic acids (NAMs) |
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| True |
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| Crosslinks differ among species. T/F? |
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| meso-diaminopimelate (mDAP) |
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| Gram negative bacteria have unusual amino acid __________ in crosslink |
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| Gram Negative |
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| If you see mDAP then you know the bacteria is what? |
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| True |
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| proteins can give a cell its shape. T/F? |
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| provides rigidity and shape to cell and prevents it from exploding due to high pressure inside cell. |
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| What is the function of the bacterial cell wall? |
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| transpeptidase |
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| how peptidoglycan can be used as an antibiotice: Penicillin inhibites what that crosslinks the peptide bonds in peptidoglycan? |
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| beta-lactamase |
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| Sometimes strains of illnesses become resistant to certain antibiotics: Many organisms produce __________ which cleaves the lactam ring of penicillin, inactivating the penicillin |
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| It is made up of polysaccharides and it lacks peptidoglycan |
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| What are Archae's cell walls made of? |
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| True. It is a "false" peptidoglycan |
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| Some Archae's cell walls consist of a pseudopeptidoglycan. T/F? |
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| Gram negative bacteria has a small amount of layers of peptidoglycan and Gram Positive bacteria has very many layers of peptido glycan (UP TO 40!) |
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| What is the main difference between gram negative bacteria and gram positive bacteria? |
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| Gram Positive Bacteria |
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| What is reinforced by negatively charged Techoic Acids? |
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| The crosslinks within peptidoglycan often have L-lysine instead of Meso-DiAminoPimelate(mDAP) |
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| How are the crosslinks in Gram Positive Bacteria different from other bacteria? |
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| Lysozome |
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| - Enzyme thats common in many bodily fluids. Destroys beta-1-4 linkage. - Destroys peptidoglycan, leading to cell lysis |
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| Lysozomes |
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| found in animal secretions & thought to be a major line of defense against infection of bacteria |
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| Outer - Lipopolysaccharide layer (LPS) Inner - Phospholipid layer |
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| What is the outer and inner layers made of in the lipid bilayer of the outer membrane of Gram Negative Bacteria |
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| Porins (= proteins) |
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| transmembrane proteins allow for permeability through the outer membrane by creating channels that cross the membrane |
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| Non-specific porins |
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| In Gram Negative Bacter these are water-filled channels through which small substances can pass. |
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| Specific Porins |
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| In Gram Negative Bacteria these are channels with binding sites for certain molecules that only allow those molecules to pass through |
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| Periplasm |
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| In Gram Negative bacteria, This is the area between the outer and cytoplasmic membranes |
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| hydrolytic enzymes & Nutrient transporter binding proteins |
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| In Gram Negative Bacteria the Periplasm contains proteins such as ________ & __________ |
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| - Polysaccharide capsule - S layer made of protein - Thick cell wall with techoic acids and held together by AA crosslinks in peptidoglycan - A thin periplasm - cytoplasmic membrane |
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| The Gram Positive envelope consists of what? |
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| - Polysaccharide capsule - Lipopolysaccharide Outer Membrane - Thin Cell Wall - Thick Periplasm - Cytoplasmic membrane |
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| The Gram Negative envelope consists of what? |
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| Genome |
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| a cell's complete set of genes. Bacterial cells may have chromosome and plasmid |
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| Chromosomes |
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| DNA is arranged to form? |
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| Prokaryotes |
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| These have a single circular chromosome & sometimes circular extrachromosomal DNA (Plasmids) |
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| Eukaryotes |
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| These have several linear chromosomes |
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| Nucleus |
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| membrane-enclosed structure that contains the chromosomes – found in eukaryotes |
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| •Nucleoid |
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| mass of DNA not bound by a membrane- found in prokaryotes |
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| Bacterial Nucleoid |
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| o Single loop of double-stranded DNA ? ~4x106 bp (base pairs) in many bacteria ? Compacted via supercoiling - Attached to cell envelope - No membrane separates DNA from cytoplasm - Replicates_ once for each cell division |
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| binary fission |
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| Growth of most microorganisms occurs by |
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| binary fission |
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| Growth of most microorganisms occurs by |
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| Divisome |
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| division apparatus in the cell formed by Fts proteins |
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| Fts Proteins |
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| required for cell division & chromosome replication |
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| FtsZ protein |
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| o Defines (determines) the division plane in prokaryotes o Polymerizes to form a ring where cell division will occur |
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| FtsA protein |
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| o ATP – hydrolyzing enzyme o Provides Energy for assembly of other proteins to the ring |
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| FtsI protein |
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| o involved in peptidoglycan synthesis for the new cell wall o activity is blocked by penicillin |
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| MreB |
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| o helps define cell shape(not just the peptidoglycan that determines shape) o forms filamentous spiral shaped bands aroud the inside of the cell under the cytoplasmic membrane (CM) o defines cell shape by directionally exerting pressure against CM (cytoplasmic membrane) o _Coccus__ shaped bacteria lack MreB gene ? Coccus is the default shape o default bacterial shape- Sphere |
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| Autolysins |
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| create opening in existing cell wall to make space for new cell wall glycans to be inserted |
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| Autolysis (spontaneous cell lysis) |
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| may occur if there is an error in inserting new cell wall material |
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| bactoprenol |
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| During peptidoglycan synthesis: helps transport these new glycan units through Cell membrane to become part of growing cell wall |
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| Hydrophobic lipid alcohol |
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| bactoprenal is a? |
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| Bactoprenol |
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| binds the N-acetylglucosamine / N-acetylmuramic acid / pentapeptide peptidoglycan precursors |
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| Transpeptidation |
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| • formation of peptide cross links between NAMs • bonds peptidoglycan precursors into expanding peptidoglycan layer • reaction is inhibited by penicillin (cell lysis occurs) |
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| Inclusion Granules |
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| Densely compacted material in cytoplasm |
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| Magnetosomes |
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| intracellular particles of magnetite (Fe3O4); allow organisms to respond to a magnetic field |
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| Glycogen |
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| bacteria stores these as carbon & energy source |
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| Polyphosphate |
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| bacteria stores this as inorganic phosphates to make cellular structure |
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| Poly-B-hydroxybutyrate |
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| Excess nutrients are stored as this and later if they don’t have enough carbon and energy then they convert this into carbon & energy source |
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| Sulfur |
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| stored in cytoplasm or periplasm and can use this as an energy source. |
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| Fimbriae |
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| ? Non-motile extensions that help bacteria attach to surfaces and to other bacteria (Neisseria, biofilms) |
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| Porphyromonas gingivalis |
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| has fimbriae that help attach to teeth |
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| Pili |
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| -Hollow, non-motile tubes made of protein called pilin that connect some cells. -Longer than fimbriae, shorter than flagella; may have 1-10 per cell |
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| Pili |
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| - Used to move DNA from 1 cell to another by conjugation - It reaches out and connects to another cell, then becomes shorter and brings 2 cells together |
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| Fimbriae |
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| Shorter than flagella and cell's have 100's per cell |
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| capsule/slime layer/ glycocalyx |
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| • Sticky polysaccharide or polypeptide layer surrounding cell • Protects cell from: o Phagocytosis o Desiccation (drying out) |
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| Proton passage |
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| What drives the rotation of flagella? |
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| TRUE |
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| Flagella can turn either clockwise or counterclockwise. Which way it turns determines the way which the cell moves. T/F? |
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| 1. Monotrichous 2. Lophotrichous 3. Peritrichous 4. Amphitrichous |
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| 1. single flagellum at 1 end 2. several flagella at 1 or both ends 3. several flagella all around cell 4. one on each end |
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| 1. Basal body 2. Hook – connects to filament 3. Filament |
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| What are the three parts of a flagella? |
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| C ring MS ring P ring L ring |
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| In Basal Body of Flagella: in G+ & G- in G+ & G- in G- only in G- only |
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| Basal Body |
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| In Basal Body of Flagella: • Imbedded within cell envelope • Made of 2 or 4 protein rings connected by a central rod |
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| C Ring |
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| In Basal Body of Flagella: - In cytoplasm. Attached to inner surface of cytoplasmic membrane |
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| MS ring |
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| In Basal Body of Flagella: In cytoplasm membrane. End of central rod is attached to MS ring. |
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| P Ring |
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| In Basal Body of Flagella: In peptidoglycan layer |
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| L ring |
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| In Basal Body of Flagella: In LPS layer |
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| Hook |
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| Curved structure made of protein; connects filament to basal body |
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| Filament |
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| • Long, rigid, helical structures made of protein called flagellin |
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| filamentous cyanobacteria, Myxococcus, Cytophaga & Flavobacterium |
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| Prokaryotes such as _________ move by gliding motility instead of flagella |
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| slime secretion |
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| Gliding can occur from ________ that moves cell along solid surfaces |
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| chemical & physical gradient |
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| Motile bacteria can respond to _______________ in environment by moving toward or away from the signal molecule. |
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| Chemotaxis Phototaxis |
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| o directed movement of organisms in response to chemical signals. o directed movement of organisms in response to light. |
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| TRUE |
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| Phototrophic bacterium rhodospirillum moves toward light. T/F? |
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| Aerotaxis Osmotaxis |
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| odirected movement of organisms in response to oxygen. directed movement of organisms in response to ionic strength (salt). |
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| Attractant |
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| - cause counterclockwise rotation o Flagella bundle together and all spin together o Push cell forwards • “Run” |
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| Repellents |
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| - cause clockwise rotation o Flagella fly apart • “Tumble” = change of direction |
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| "random walk" |
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| Runs + Tumbles = ? |
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| Receptors |
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| - detect attractant concentrations • Examples of attractants are sugars and amino acids |
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| • ELECTRON FLOW, to drive all life processes • Drives ions into, out of cells • Ion flow is Used to create ATP • ENERGY, to move electrons • MATERIALS to make cell parts • Macro-Nutrients – CHONPS (carbon, hydrogen, oxygen, … •organisms absolutely need a lot of these to survive |
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| All life requires what? |
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| Lithotrophs and Organotrophs |
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| What are two sources of electrons that contribute to electron flow? |
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| Lithotrophs -Iron |
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| What are Inorganic molecule that donates elctrons? ex.? |
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| Organotrophs -Glucose |
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| What are Organic molecules that act as;electron donors? Ex.? |
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| Nitrogen and Oxygen Respiration |
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| What are examples of ultimate Inorganic electron acceptors If these Inorganic acceptors are being used then the molecule is growing by _____________ |
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| Pyruvate Fermentation |
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| What is the most common ultimate Organic electron acceptor If this is being used then the molecule is growing by __________________ |
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| Phototrophs and Chemotrophs |
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| Sources of enery for microbes? |
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| Phototrophs |
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| • Light energy excites electrons • Excited molecules are electron donors |
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| Chemotrophs |
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| • Chemicals are electron donors • oxidation of chemical o Oxidation = donation of electrons |
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| Macro-Nutrients |
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| • Major elements in cell macromolecules needed in large amounts o C, H, O, N, P, S • Ions necessary for protein function o Mg2+, Ca2+, Fe2+, K+ |
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| Mg2+, Ca2+, Fe2+, K+ |
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| Macro-Nutrients: Ions necessary for protein function? |
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| C, H, O, N, P, S |
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| Major elements in cell macromolecules needed in large amounts |
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| Micro-Nutrients |
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| •Needed in very small amounts •Trace elements (Co, Cu, Zn, etc) •Growth factors (organic compounds) necessary for enzyme function |
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| Carbon |
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| large amount needed by cells to form organic compounds (amino acids (proteins), fatty acids, sugars, & nitrogenase bases) to carry out cellular functions |
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| Autotrophs |
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| prokaryotes that can make all cellular structures from CO2 |
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| Heterotrophs |
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| must obtain carbon from organic compounds (most prokaryotes) |
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| 79% |
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| What percent of the air we breathe is nitrogen gas? |
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| Ammonia and Nitrate |
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| Most prokaryotes obtain nitrogen from compounds such as |
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| Chemoorganitrophs |
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| energy from oxidation (removing electrons) of organic compounds |
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| Chemolithotrophs There is less competition |
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| Energy from oxidation of Inorganic compounds. Only in Prokaryotes. Why is this an advantage? |
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| Heterotrophs |
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| Carbon sources: Carbon source is Organic Carbon compounds |
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| Autotroph |
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| Carbon source is carbon dioxide |
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| Photoautotroph "Photo"autotroph" |
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| What obtains energy from light and carbon from CO2? |
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| Passive diffusion |
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| • Some substances pass freely through membranes O2, CO2 |
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| Facilitated diffusion |
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| - Protein transporters pass material into/out of cell - follows gradient |
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| ATP binding cassette(ABC)Transporters Symport and Anitport Phosphotransferase (PTS) system (type of group translocation) |
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| Examples of Active Transport |
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| Active Transport |
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| type of transport when materials are passed against the gradient |
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| ATP binding cassette transporters (ABC transporters) |
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| - Use ATP to pass material into cell - Efflux ___ transporters can pump antibiotics out of cell |
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| Symport and Antiport |
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| - The gradient of one molecule transports another - K ion or Na ion helps sometimes and must determine the charge. |
