Practice Quiz Unit 3 Flashcards
Peptidoglycan
Both gram+ and gram-.
Located in cell wall. Gram+ cells have very thick cell wall due to peptidoglycan.
Teichoic Acids
Gram+.
Attaches cell wall to membrane.
Lipopolysacharride (LPS)
Gram-.
Located in outer membrane.
Outer Memrane
Gram-
Periplasmic Space
Gram-.
Located between two membranes.
Porin Proteins
Gram-.
Located in outer membrane and form transmembrane channels that allow passage of hydrophilic molecules.
Lipid A
Gram-.
Toxic portion of lipopolysaccharide.
Component of out membrane.
O Antigen
Polysaccharide antigen located in lipopolysaccharide.
H Antigen
Flagellar antigen.
Beta Lactam Antibiotics
More effective in cells during logarithmic growth phase. Targets newly forming peptidoglycan
Quinolone
Targets DNA gyrase and DNA topoisomerase (?).
Coagulase
Promotes deposition of fibrin and walls off S. aureus.
Infection
Microbe enters into relationship with host.
Pili
Bacterial structure most commonly involved in mediating adherence of bacteria to human cells.
Enterococcus Spp.
Gram+. Forms chains.
Mostly likely to be found as part of normal bowel flora.
Clostridium difficile
Associated with antibiotic use due to antibiotic resistance. Causes diarrhea.
Part of normal flora w/o causing disease.
GI disease related to toxin production.
McConkey Agar
Allows growth of gram- bacteria only.
Lactose Fermenting Bacteria (when grown on McConkey agar)
E. coli, Klebsiella pneumoniae
Gram Stain
Adheres to peptidoglycan, which makes thick cell wall in gram+ cells.
Genetic Recombination
Allows bacteria to express different antigenic forms of pili.
Bacteriophage Converion (Lysogenic Conversion)
Mechanism of phage mediated transfer. Process where bacteria incorporates phage DNA that confers a new phenotypic trait into own genome. Allows diptheriae to express diptheria toxin.
Klebsiella pneumoniae
gram- rod
Glycocalyx
Virulence factor most associated with Staph epidermis
Transformation
Naked strands of DNA are incorporated into bacterial genome. Possible in both gram+ and gram- bacteria.
Generalized Transduction
Mechanism of phage-mediated transfer. Gene transfer mediated by a bacteriophage, where any segment of donor phage (bacterial?) genome is passed into another cell.
Bacterial Conjugation
Form of genetic transfer that is dependent upon contact between donor and recipient cells. Usually mediated by certain types of bacterial plasmids.
Virulence Genes
Are often expressed only under conditions of low iron.
May be obtained in complex transposons, during bacteriophage conversion, or in the acquisition of plasmids.
Lytic Infection
Phage multiplication leading to host cell lysis.
Transposition
DNA sequence that can change its position within the genome.
prophage
Consists of phage DNA which is linearly inserted into host cell genomes where it becomes passively replicated as part of host bacterial chromosome.
Insertion Sequence Transposon
Encode transposase. Inactivate genes into which they are transposed or turn on expression of adjacent genes.
Complex Transposons
Similar to regular transposons but carry additional genes such as those encoding antibiotic resistance, toxins, or other virulence factors.
Endotoxin
LPS from cell walls of gram- bacteria
Exotoxin
Toxin secreted by bacteria.
Enterotoxin
Exotoxin that acts in GI system.
