Microbiology TEST 1
Microbiology 4th Semester
Microbiology 4th Semester
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Cartes-fiches
Name Spore forming gram positive bacteria
HINT: u must name 6 Bacteria
only Gram-Positive bacteria are spore-Formers!!
- bacillus anthracis
-bacillus cereus
-clostridium botulinum
-clostridium tetani
- clostridium difficile
-clostridium perfringes
name non-spore forming rods of gram positive bacteria
- listeria monocytogenes
-corynebacterium diphteriae
-corynebacterium jeikeium
-corynebacterium urealyticum
name gram positive cocci that form clusters
-straphylococcus aureus
-staphylococcus epidermidis
-straphylococcus saprophyticus
name gram positive cocci that form strips of cocci
-streptococcus pyogenes (GAS)
-streptococcus agalactiae (GBS)
- streptococcus viridans
-streptococcus pneumoniae
-enterococci ( streptococcus faecium, streptococcus faecalis)
What are prokayotes?
What is in the Cytoplasm of prokaryotes?
What is in the Cytoplasm of prokaryotes?
Summary what is in the cytoplasm?
-plasmid
-single, circular DNA haploid genome
-70S ribosome
Summary what is NOT in the cytoplasm?
-nuclear membrane
-nucleolus
- mitochondria
-endoplasmic reticulum
-golgi bodies
Cytoplasmic membrane or cell membrane contains
Cytoplasmic membrane can be used for cellular respiration?
Which is the exceptional bacteria that do contain sterols in cytoplasmic membrane?
mycoplasma
Function of Cytoplasmic membrane
NAME 6 of them
1. -surrounds cytoplasm (containing ribosomes,plasmid& single,circular DNA haploid genome)
2. -site for cellular respiration
3. -has NO Sterols except mycoplasma
4. -is surrounded by Cell Wall containing peptidoglycan layer
5. -is composed of phospholipid bilayer and has proteins embedded
6. - is the innermost layer of prokaryote
Cell wall is composed of
-peptidoglycan layer
-protein
-lipids
Gram-Positive Cell Wall is composed of:
The single, double-stranded, circular bacterial chromosome is not in the nucleus but in the:
nucleoid
Only bacteria that don't have a peptidoglycan layer are ?
mycoplasmas and ureaplasmas
Cell wall or peptidoglycan layer composed of?
Peptidoglycan monomer is composed of two joined amino sugars:
Function of Peptidoglycan layer in Gram-Positive
-cell shape and structure
-protection from environment&complement killing
- is a meshlike exoskeleton
Function of peptidoglycan layer in Gram-Negative
- cell shape and structure
Function of Cell Walls/peptidoglycan Layer surface proteins in Gram-Positive
Function of Cell Wall componend lipoteichoic acid in Gram-Positive
Function of Cell Wall componend teichoic acid in Gram-Positive
used as antigenic determinant for serological identification
What are components of Gram-Negative Bacteria?
Gram-Negative have specific outer membrane named ?
Unique phospholipid bilayer with a normal inner portion with hydrophobic tails extending to center and LPS (lipopolysaccharide) with porin proteins embedded.
What binds the unique outer membrane LPS in gram-negative bacteria to the middle layer the peptidoglycan layer?
murein lipoprotein
What makes the outer layer of gram-negative bacteria so unique?
HINT: it is a phospholipid bilayer
It is a phospholipid bilayer:
The innermost portion of the bilayer has hydrophobic tails directed to the center
The outermost portion contains LPS!
LPS is composed of 3 covalently linked components
LPS is composed of 3 covalently linked components, name them:
Outermost: O-specific side chain or O-antigen
middle portion: core polysaccharide
innermost portion: The ENDOTOXIN = LIPID A
Function of LPS
Lipid A is a
Lipid A the ENDOtoxin when lysed by 1. __________ of our body, fragments of mebrane containing Lipid A are released into 2.__________ causing 3._______ 4.________and possibly fatal 5._______shock.
1. immune system
2. circulation
3. fever
4. diarrhea
5. endotoxic shock/ septic shock
LPS choose right answers
Function of Outer membrane of Gram-Negative bacteria
Function of periplasmic space in gram-negative
The area btw the external surface of cytoplasmic membrane and internal surface of peptidoglycan layer:
This space contains enzymes involved in transport, degradation and synthesis
Enzymes like: -protease,phosphatase,lipases, nucleases
Enzymes with pathogenicity/virulence factor: -collagenases, hyaluronidases, proteases and ß-lactamase
How is Teichoic acid and Lipoteichoic acid bond to Gram-Positive bacteria?
What is a capsule?
General Capsule Summary:
HINT: u must name 7 things
- closely surrounded by loose polysaccharide or protein layer
-protein layer/ polypeptide layer only in bacillus anthracis (y-D-glutamic acid)
-sometimes referred as slime layer or glycocalyx
-is a major virulence factor
-protects bacteria from phagocytosis of macrophages or neutrophiles
- capsule can be detected under microscope only by INDA INK or by Quellung Reaction
-antibodies bind to capsule and antibodies Fc-portion can be detected by macrophages/neutrophiles, which enables it to phagocytose the bacteria (binding of antibodies to capusle of bacteria known as = op-soni-zation)
Capsule is hard to see under microscope, thus what methods are used to visualize?
India Ink - capusle doesnt stain, thus capsule appears as HALO
Quellung reaction - bacteria mixed with antibodies that bind on capusle, causing swelling of capsule with WATER
Capsules function?
