Intro To Bacteria Flashcards
What colour to gram positive bacteria stain?
Purple
What colour do gram negative bacteria stain?
Red/pink
What shape are cocci?
Spherical
What shape are bacilli?
Rod shaped
What is a PBP?
Pencil in binding protein- involved in the stages of peptidoglycan synthesis, which is a major component of bacterial cell walls.
Inhibition of PBP lead to irregular wall structure.
What peptidoglycan?
Polymer consisting of sugars and amino acids
Mesh like layer forming cell wall.
Where are lipopolysccharides found?
Outer membrane of gram Negative Bacteria cells.
What do capsules do?
Helps bacteria survive, prevents phagocytosis.
Full of water
What is virulence?
A bacteria’s ability to harm host
What is flagellum and its function?
Thread-like structure
Allows bacteria to swim.
What is fimbriae and its function?
Series of thread-like projections
Found more on gram negative bacteria cells.
Allow bacteria to stick to cells/surfaces/host cells
What is a pilus?
A bridge, which forms between bacterial cells allowing transfer of plasmids.
What is a bacteriophage?
A virus that infects and replicates within bacterium
Sit on surface and enter through transduction.
What are spores?
Dormant structures
Formed in response to adverse conditions environmentally.
Help in survival of bacteria in high temp etc
Usually found in gram positive.
Layers of gram positive?
Plasma membrane,
Periplasm space
Thick layer of peptidoglycan
Layers of gram negative?
Plasma membrane Periplasmic space Thin layer of peptidoglycan Periplasmic space Outer membrane of lipopolysaccharides
What is binary fission?
Bacteria replication
One bacterial cell divides into two daughter cells
What do spontaneous mutations cause?
Genetic variation, transfer of DNA
Most likely to be advantageous for cell.
Which bacteria can only be seen by microscope and stain?
Individual bacteria
Which bacteria can be cultured and seen by the human eye?
Colonies of individual bacteria.
What is haemolysis?
Rupture of RBCs and contents are released into surrounding fluid.
Streptococci, partial, compete and non-haemolytic
What is coagulase used for?
Distinguishes different types of staphylococcus
Miscellaneous organisms for which gram stain is not applicable?
AAFB
Spirochatetes
Miscellaneous (chylamidia, ricksetta, mycoplasma)
