Biochemistry, Microbiology, and Immunology Week 8 Flashcards
what are bacteria?
single celled organisms
very small
binomial nomenclature includes
the genus and species
the genus name is always
capitalized
the species name is never
capitalized
what is a strain or variety?
a culture derived from a single parent that differs in structure or metabolism from other cultures of the species
what is a type?
a subspecies that can show differences in antigenic makeup (genetics), susceptibility to bacterial viruses, and pathogenicity
four basic shapes of bacteria
rod shaped
round shaped
spiral shaped
spirochetes
rod shaped is also called
bacilli
round shaped is also called
cocci
spiral shaped is called
spirilla
what is the difference between spirillum and spirochete
spirochete is more zig sag and spirillum is more wavy
what are the four groups based on cell wall composition
gram-positive cells
gram-negative cells
bacteria without cell walls
bacteria with chemically unique cell walls
what is peptidoglycan
a macromolecule composed of a repeating framework fo long chains sugars cross-linked by short peptide fragments
what is peptidoglycan composed of
two sugars (NAG and NAM)
they alternate in the backbone
polypeptide rows
what does a gram positive wall mean
it absorbs stain
tightly bound acidic polysaccharides
cell membrane - space - cell wall
what does a gram negative cell wall mean
does not absorb stain
consists of an outer membrane containing lipopolysaccharide (LPS)
thin shell of peptidoglycan between inner and outer membranes
what are the bacteria called that have no cell walls
mycoplasma
smallest known organisms
do not stain with the gram stain
what are the three types of bacterial energy production
autotrophs
chemotrophs
heterotrophs
autotrophs
make their own energy using solar energy
chemotrophs
make their own energy using chemical energy
heterotrophs
obtain food from other organisms
three types of respiration in bacteria
obligate anaerobes
faculative anaerobes
obligate aerobes
obligate anaerobes
live without oxygen
faculative anaerobes
can live with or without oxygen
obligate aerobes
cannot live without oxygen
what are the two types of reproduction in bacteria
binary fission
conjugation
what is conjugation:
one genetic donor cell F+ contains plasmids that are transferred to the recipient cells F-
when the plasmid becomes incorporated into the chromosome, the cell is called an
Hfr - high frequency recombinant
Hfr factor can be transferred to
another cell
cyanobacteria are
gram negative
spirochetes are
gram negative
pyogenic cocci are
gram negative and gram positive
pyogenic cocci are responsible for
1/2 of the human bacterial infections
endospore forming bacteria is
gram negative
endospore bacteria are able to lie
dormant
purple and green bacteria
photosynthesis process without oxygen or water
uses chemical component of Sā
vibrios are
gram negative
myxobacteria
glide over the surface, have spores that release into the environment
actinomycetes are
gram negative
actinomycetes perform
decomposition
they are pathogens
radioresistant is
gram negative
radioresistant survive a large dosage of
radiation
survive DNA damaging chemicals
what are viruses
made up of genetic material and protein
structure of viruses
core of nucleic acid (either DNA or RNA)
what is a retrovirus
changes the genetic info of a cell
retroviruses contain
RNA and DNA
to be able to take over a host cell, the retrovirus must be able to convert
the rna into dna
to accomplish the conversion of RNA into DNA, the retrovirus inserts an enzyme called
Reverse Transcriptase
what is a bacteriophage
viruses that infect bacteria
bacteriophages are responsible for
transduction
what is transduction
the process by which DNA is transferred from one bacterium to another by a virus
what are the two life cycles of viruses
lytic cycle
lysogenic cycle
what is the lytic cycle
the virus immediately infects the host cell
small pox
what is the lysogenic cycle
lay dormant in the cell
herpes
chicken pox
