microbiology quiz 2-18-15 Flashcards
what is the name of the cocci , that divide in pairs?
diplococci
what is the name of the bacilli, that divide in pairs?
diplobacilli
does the gram + cell wall have an outer membrane?
no
what is the name of the cocci that divides in irregular clusters?
staphylococci
what is the name of the bacilli that divide into chains?
streptobacilli
what is the chemical composition of a gram – cell wall?
Lipopolysaccharide ( LPS) and peptidoglycan
what is the chemical composition of a gram + cell wall?
peptidoglycan and teichoic acid
does a gram– cell wall have a periplasmic space?
yes it is a thick, viscous, gelatinous layer
does a gram + cell wall have a periplasmic space?
yes but it is extremely thin
does a gram – cell wall have an outer membrane?
yes
what is the name of the cocci that divide into groups of four?
tetrad
what is the name of the cocci that divide into chains?
streptococci
which group of bacteria (demonstrated by gram stain) have a thin peptidoglycan layer and cell wall?
gram – bacteria ( stain red)
what are the fine protein hair like bristles emerging from the bacterial cell surface called?
fimbriae
name the 2 major groups of bacterial external structures known as appendages
- those that provide motility- flagella and axial filaments
- those that provide attachment- fimbriae and pili
which group of bacteria (demonstrated by gram stain) have a thick peptidoglycan layer and cell membrane?
gram + bacteria ( stain purple)
what is the purpose of the flagella?
motility, it rotates 360 degrees and moves the bacterial cell in a run and tumble motion
what is the name of the coating of molecules external to the cell wall, made of polysaccharides or polyproteins?
Glycocalyx - its a sugar coating that is used for attachment, evading phagocytosis, protects it from drying out and protects it from chemotoxins
what is the filament made up of?
a protein called flagellin, its approximately 20nm in diameter and 1 to 70um in length
what is the counter-clock-wise motion of the flagella called and how does it affect the bacteria?
this is called “run” and it moves the bacteria forward
what is the clock-wise motion of the flagella called and how does if affect the bacteria?
this is called “tumble” and it stops the bacteria it tumbles and changes direction
what is the purpose of the “run” and “tumble” motion of the bacteria?
it is to evade or move toward things its trying to reach or avoid
name the 3 parts of the flagella
- the filament
- the hook- is the sheath anchored to the cell by the basil body
- the basil body- is a stack of rings firmly anchored through the cell wall to the cell membrane
name the 2 types of glycocalyx
- slime layer
2. capsule
what glycocalyx layer is loosely organized, loosely attached, has holes in it, and is not solid?
the slime layer
what glycocalyx layer is organized, tightly attached, continuous solid layer?
the capsule
T or F
bacteria that have a capsule are more likely to cause disease, reproduce and hang around longer?
true
what is the term for a bacteria’s transferring of the genetic information from one bacterial cell to another via the pillus?
conjugation
T or F
all bacteria are able to perform conjugation?
false
which type of bacteria ( through gram staining) are more likely to perform conjugation?
gram -
how do spirillum/ spirilla move?
they move by a polar flagella, can be single or in tufts, they swim by rotation,
what is the rigid structure made of pilin protein and what is its function?
the pili, it joins bacterial cells for partial DNA transfer called conjugation ( sex bridge) and is found in gram - cells
what bacterial shape has a rigid helix and is mobile with a polar flagella?
spirillum ( single) spirilla (pleural)
what is the cocci arrangement that divides in groups of 4?
tetrad
what is the name of the cocci arrangement that divides into pairs?
diplococci
what is the cocci arrangement that divides into chains?
streptococci
what are the flexible bacterial shape, that move by means of axial filaments?
spirochete
what is the helical bacteria shape, that is like a loose “s” shape and move by polar flagella?
spirillum
what term is used to describe a motile bacteria having a tuft of flagella at one end?
lophotrichous
what term is used to describe a motile bacteria having a single flagellum at one end?
monotrichous
what term is used to describe a motile bacteria having flagella dispersed all over the surface of the cell?
peritrichous
what term is used to describe a motile bacteria having flagella at both ends of the cell?
amphitrichous
what is the function of the run and tumble motion?
this allows the bacteria to respond to its elements
what is the name of the cocci arrangement that presents as a cluster?
staphylococci
name the arrangement of elongated bacteria that divide into pairs
diplobacilli
name the arrangement of elongated bacteria that line up in a chain
streptobacilli
what is the name of the cell wall that is composed of proteins and carbohydrates arranged in a lattice pattern NAM NAG?
peptidoglycan