Chapter 4 – Microbiology Answers – Flashcards

Unlock all answers in this set

Unlock answers
question
Bacteria used as insecticide
answer
Bacillus thuringensis
question
Bacteria used in warfare causing 1. anthrax and 2. food poisening
answer
Bacillus anthracis and Clostridium botulinum
question
5 features of prokaryotes
answer
1. one circular chromosome
2. no histones
3. no organelles
4. peptidoglycan cell walls
5. binary fission
question
Bacillus
answer
rod shaped
question
coccus
answer
spherical
question
spirillum
answer
wave shaped
question
vibrio
answer
curved rod
question
spirochete
answer
corkscrew
question
strepto
answer
chain
question
staphyl
answer
cluster
question
8 cell
answer
sarcinae
question
2 examples of pleomorphic bacteria
answer
1. Rhizobium
2. Corynebacterium
question
adavtages of having small size (3)
answer
1. accumulate nutrients quickly
2. metabolize quickly
3. grow quickly
question
largest bacteria known
answer
Epulopiscium sp.
question
What is glycocalyx made of?
answer
polysaccarhides
question
2 functions of glycocalyx
answer
1. source of food under adverse conditions
2. absorbs water, prevents dehydration
question
biofilm is associated with this type of glycocalyx
answer
slime layer
question
why does a capsule increase pathogencity of bactuera?
answer
white blood cells cannot grab them, prevents phagocytosis
question
3 functions of cell wall
answer
rigidity, shape, prevents osmotic lysis
question
Tetrapeptide side chaings hang from...
answer
NAM
question
Peptide cross bridges do what
answer
link layers of PG together
maintain integrety of cell wall
question
# layers of PG in Gram + cell wall
answer
10-12
question
Teichoic acids roles and composition
answer
present in gram +
regulate movement of cations

alcohol/glycerol and phosphate
provide antigenic variation
question
antigentic variation
answer
ability of distinguish between bacterial cells
question
Gram negative cell wall
answer
thin layer of PG
no teichoic acids
outer membrane
question
composition of outer membrane in gram neg
answer
LPS (lipopolysarcharide)
-made of Lipid A and O polysaccharide
question
Lipid A
O polysaccharide
answer
endotoxin
antigen, used for distinguishing bacteria
question
example of a bacteria whose antigen identifies it
answer
E Coli O157:H7
question
how penecillan works
answer
kills PG in gram + bacteria, specifically by breaking peptide cross bridges
question
acid fast cell wall composition
answer
waxy lipid (mycolic acid) bound to peptidoglycan
question
2 examples of acid fast cell wall bacteria
answer
1. Mycobacterium - causes TB
2. Nocardia
question
mycoplasma bacteria
answer
-lack cell walls
-there are sterols in plasma membrane help protect from lysis
-smallest of all bacteria, most contaminating in labs
question
archea cell wall composition
answer
pseudomurein or pseudoPG
lacks NAM and D-amino acids
question
Plasma membrane composition
answer
phopholipid bilayer and proteins
question
fluid mosaic model
answer
lipids and proteins are free to move around, about as viscous as olive oil
question
functions of plasma membrane
answer
-selective permiability
-enzymes for ATP production (lack mitochondria)
-photosynthetic pigments
question
damage to plasma membrane caused by
answer
1. alcohol
2. detergent
3. polymyxin antibiotics
casue leakage,death
question
simple diffusion
answer
passive transport, usually gaseous molecules
question
facilitated diffusion
answer
passive, larger molecules ex. glycerol
goes through transporter protein
question
osmolerity in cell
answer
0.85%, ex. saline
question
classical active transport
answer
-uses ATP or PMF
-substance not altered across membrane
-uses transporter proteins
question
group translocation
answer
molecular is chemically altered, this prevents it from leaving cell
ex. glucose is phosphorolated
question
what bacteria does not have flagella?
answer
cocci
question
flagellin proteins in the filament are
answer
H proteins, recognized by immune system
ex. E Coli
question
monotrichous
answer
1 flagellum at 1 end
question
ampthitrichous
answer
1 flagellum at each end
question
lophotrichous
answer
many flagellum at one end
question
peritrichous
answer
entire cell wall has flagella
question
chemotaxis and phototaxis
answer
movement towards or away from a chemical or light
question
what bacteria causes stomach ulcers
answer
Helicobacter pylaorii
strong flagella can swim through mucous
question
what bacteria causes stomach ulcers?
answer
Helicobacter pylaorii
strong flagella can swim through mucous
question
mode of movement by bacteria in ocean
answer
gaseous vesicles
question
what type of cells have pili and fimbriae?
answer
gram negative
question
function of pili
answer
gliding/twitching movement
DNA transfer
question
Fimbriae
answer
used to attach to things, eg inside of small intestine
question
structures found in cytoplasm
answer
DNA and ribosomes
question
bacterial chromosome (nucleoid) characteristics (4)
answer
1. no nuclear membrane
2. no histones
3. circular DNA
4. Haploid DNA (only 1 copy of each gene)
question
plasmids description
answer
circular, double stranded DNA, extra-chromosomal
autonomis from nucleoid
not required by cell
question
benefits of plasmids
answer
can contain genes for:
-antibiotic resistance
-toxic metal resistance
-production of enzymes
question
transfer of plasmids
answer
takes place through pili
question
function of ribosomes
answer
make proteins
question
somposition of bacterial ribosome
answer
small subunit = 30S
large subunit = 50S
complete ribosome = 70S
question
human ribosome complete unit
answer
80S
question
antibiotic effect on ribosomes
answer
antibiotics can be targeted towards bacterial ribosomes without harming human ribosomes
question
content and use of metachromatic granule
answer
phosphate, used to make ATP
question
presence of metachromatic granule indicates what species of bacterium?
answer
Corynebacterium diphtheriae
question
who produces endospores?
answer
gram +
question
when are endospores produced?
answer
when a bacterium is stressed because of lack of C or N
question
how long can endospores survive?
answer
100k+ years
question
the process of endospore formation is known as
answer
sporulation
question
endospores are made of what?
answer
DPA dipicolnic acid
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New