microbiology 5 Flashcards
_____Forms mesh like exoskeleton but is porous enough to allow diffusion of metabolites
peptidoglycan
peptidoglycan can interfere with_____, is mitogenic for _____ and has_____ activity
phagocytosis
lymphocyte
pyrogenic
b1-4 bond can be degraded by ______
lysosome
Precursor form of the peptide (in peptidoglycan) has an extra ______, which is released during the ________ step
D-ala
cross linking
(in peptidoglycan) Prefabricated subunits are ________
assembled on the inside of the cell.
In Gram-positive bacteria, how does it have a strong rigid cell wall?
Peptidoglycan forms multiple layers and often cross linked in 3 dimensions to give strong rigid cell wall
what is the acidic polysaccharide present in cell wall of bacteria
Teichoic acid
what is the coiled portion of the cell membrane
the mesosome
the cell wall Contains ______ or_______ phosphate residues
glycerophosphate
ribitol
what charge is the cell wall?
negatively charged
what are the Glycerol containing acids that are bound to membrane lipids of Gram-positives
lipoteichoic acids
proteins form part of the ______
cell wall
what are the actions of M protein of Group A Streptococcus?
- Present as fine processes called fimbriae
- Protects bacteria from phagocytosis
what are the actions of Protein A of S. aureus?
- Binds Fc region of IgG
- Competes with neutrophil receptors for the Fc region of opsonising antibodies
what part of gram negative bacteria cell walls accounts for 5-10% only of its weight?
in the periplasmic space between the CM and the inner surface of the outer membrane
Periplasmic space contains _______
a variety of hydrolytic enzymes necessary to break down large macromolecules for metabolism
what are the enzymes in the periplasmic space?
phosphatases, lipases, nucleases and carbohydrate degrading enzymes
which system do bacterial cells use to sense its outside environment?
the chemotaxis system.
some components of the chemotaxis system is found in the ______
periplasmic space
In pathogenic bacteria, there will be virulence factors such as ____, _____, _______, and _______
collagenases, hyaluronidases, proteases and beta-lactamase.
outer membrane is unique to _______ prokaryotes
gram-negative prokaryotes
_____maintains structure and forms permeability barrier to large molecules. e.g. lysosome
the outer membrane of gram negative prokaryotes.
the outer membrane of prokaryotes Provides______
Provides protection from adverse environmental conditions such as the human digestive system
_____ is an amphipathic molecule known as lipopolysaccharide (LPS)
the outer membrane of gram negative prokaryotes.
