Introduction to Bacteria 1 Flashcards
<p>What does the structure of bacteria contain?</p>
<p>Capsule</p>
<p>Cell wall</p>
<p>Cytoplasmic/inner/plasma membrane</p>
<p>Cytoplasm</p>
<p>Ribosomes</p>
<p>Single chromosome, no nucleus</p>
<p>Flagellum</p>
<p>Finbriae</p>
<p>What does the cytoplasm do?</p>
<p>Contains nutrients taken up from the environment</p>
<p>What do ribosomes do?</p>
<p>Site of protein synthesis</p>
<p>What does the cytoplasmic membrane do?</p>
<p>Diffusion of ions and nutrients</p>
<p>What does the cell wall do?</p>
<p>Combats osmotic stresses</p>
<p>What does the capsule do?</p>
<p>Helps the bacteria to survive in humans, for example escaping macrophages</p>
<p>What do flagellum do?</p>
<p>Allows the bacteria to move</p>
<p>What does fimbriae do?</p>
<p>Important for attachment</p>
<p>What do chromosomes do?</p>
<p>Contains DNA</p>
<p>What does the plasmid do?</p>
<p>DNA outside of the chromosome</p>
<p>What kind of bacteria has an additional membrane?</p>
<p>Gram negative bacteria</p>
<p>What kind of bacteria has a thicker layer of peptidoglycan?</p>
<p>Gram positive bacteria</p>
<p>What are the layers (going inwards to outwards) in gram positive bacteria?</p>
<p>Plasma membrane</p>
<p>Periplasmic space</p>
<p>Peptidoglycan</p>
<p>What are the layers (going inwards to outwards) in the plasma membrane of gram negative bacteria?</p>
<p>Plasma membrane</p>
<p>Periplasmic space</p>
<p>Peptidoglycan</p>
<p>Periplasmic space</p>
<p>Outer membrane (lipopolysaccharide and protein)</p>
<p>What does the outer membrane of gram negative bacteria contain?</p>
<p>Lipopolyassacharide and proteins</p>
<p>What colour does gram positive bacteria appear in gram staining?</p>
<p>Purple</p>
<p>What colour does gram negative bacteria appear in gram staining?</p>
<p>Red</p>
<p>What are two classes of bacteria after aerobic/anaerobic?</p>
<p>Cocci or bacilli</p>
<p>What do cocci bacteria look like?</p>
<p>Spherical shaped</p>
<p>What do bacilli bacteria look like?</p>
<p>Rod shaped</p>
<p>What proteins are present on the cell surface of bacteria that creates cross links?</p>
<p>Penicillin binding proteins (PBP)</p>
<p>What are examples of penicillin binding proteins?</p>
<p>Transpeptidases</p>
<p>Carboxypeptidases</p>
<p>Endopeptidases</p>
<p>What are lipopolysaccharides?</p>
<p>They are present only on gram negative bacteria and elicit a strong immune response in animals and humans</p>
<p>What does the capsule provide bacteria with?</p>
<p>Water to survive in many environments</p>
<p>What are the different kinds of flagellum?</p>
<p>A-monotrichous vibrio cholera (one)</p>
<p>B-lophotrichious spirillum spp (one point)</p>
<p>C-amphitchous rhondospirillum rabrum (both sides)</p>
<p>D-peritichous (all over)</p>
<p>What do some bacteria release?</p>
<p>Spores which help it to obtain nutrients</p>
<p>When does spore formation occur?</p>
<p>When there is not enough nutrients for fission or environmental factors do not allow it</p>
<p>What does spore formation allow?</p>
<p>The bacteria to survive in tough environments</p>
<p>What is the process of spore formation?</p>
<p>1) DNA condenses and lines itself in the centre of the cell</p>
<p>2) DNA divides into two copies</p>
<p>3) Mother cell invaginates to form developing forespore</p>
<p>4) Moth cell engulfs developing spore which is surrounded by two membranes</p>
<p>5) Mother cell DNA is degraded</p>
<p>6) Peptiglycan laid down to form cortex</p>
<p>7) Ca2+enters and water is removed from the spore</p>
<p>8) Protein coat forms exterior to cortex</p>
<p>9) Some spores form exosporium</p>
<p>10) Enzymes destroy mother cell and mature spore is released</p>
<p>What are exoporium?</p>
<p>Outer surface layer of mature spores</p>
<p>What provides a mechanism for antibiotic resistance?</p>
<p>The plasmid</p>
<p>What kinds of bacteria prefer what during mating?</p>
<p>Gram negative prefers gram negative</p>
<p>Gram positive prefers gram positive</p>
<p>What is conjugation?</p>
<p>Process by which bacterium transfers genetic material to another through direct contact</p>
<p>What are other names for gram positive and gram negative bacteria?</p>
<p>F+ are gram positive</p>
<p>F- are gram negative</p>
<p>What do gram positive bacteria contain in terms of mating?</p>
<p>F plasmid which allows them to form F pills</p>
<p>What eventually happens when gram positive and gram negative bacteria are mixed together?</p>
<p>They all become gram positive</p>
<p>What is the process of conjugation?</p>
<p>1) F pills of donor cell (gram positive) recognises and binds to proteins on gram negative cell wall</p>
<p>2) Plasmid becomes mobilised for transfer</p>
<p>3) Single strand of plasmid enters the recipient cell</p>
<p>4) Inside recipient cell a complimentary strand is synthesised</p>
<p>What is binary fussion?</p>
<p>The process by which bacteria replicates</p>
<p>What may genetic variation occur due to?</p>
<p>Spontaneous mutations</p>
<p>Transfer of DNA</p>
<p>What are spontaneous mutations?</p>
<p>Mutations that occur randomly with no influence from the environment</p>
<p>What does transfer of DNA occur by?</p>
<p>Conjugation</p>
<p>Transformation</p>
<p>Transduction</p>
<p>What is transformation?</p>
<p>Genetic alteration due to uptake of extracellular DNA that is advantageous</p>
<p>What is transduction?</p>
<p>Foreign DNA is introduced into a cell by a virus</p>
<p>What is transduction caused by?</p>
<p>Bacteriophages</p>
<p>What are bacteriophages?</p>
<p>Viruses that infect bacteria</p>
<p>What do bacteriophages contain?</p>
<p>Head</p>
<p>Collar</p>
<p>Tail</p>
<p>End plate</p>
<p>Tail fibre</p>
<p>What does the end plate and the tail on a bacteriophage do?</p>
<p>Helps it to attach to bacteria cells</p>
<p>What are the two cycles that bacteriophages enter their DNA into bacteria through?</p>
<p>Lytic</p>
<p>Lysogenic</p>
<p>What is the lytic cycle?</p>
<p>Where the phage overtakes the machinery in the bacteria and starts replicating to form more phages, bacteria cell then bursts and releases them</p>
<p>What is the lysogenic cycle?</p>
<p>DNA from the phage integrates with the hosts chromosome, it can remain dormant or replicate</p>
<p>What can individual bacteria be seen by?</p>
<p>Microscope at 1000x with an oil immersion lens</p>
<p>Staining (such as gram or flourescent)</p>
<p>What can the naked eye see?</p>
<p>Colonies of bacteria</p>
<p>What is culturing used for?</p>
<p>To identify exactly what species of bacteria is present</p>
<p>What do selective mediums allow?</p>
<p>Certains species to grow</p>
<p>What is bacteria naming based on?</p>
<p>The genus and the species</p>
<p>For example for Staphylococcus aureus Staphylococcus is the genus and aureus is the species</p>
<p>What properties do strains of bacteria within the same species have?</p>
<p>Similar characteristics</p>
<p>What can be used to identify strains?</p>
<p>DNA typing</p>
