Test 1 Flashcards
ribozyme has
genetic and enzymatic activity
acidophile grows optimally in what environment?
pH
neutrophiles grow optimally in what environment?
pH from 5.5-8.5
alkalophiles grow optimally in what environment?
pH >8.5
What are the different shapes of bacteria?
cocci= spherical bacilli= rod vibrios= curved rod spirilla= sprial pleiomorphic= variable in shape
what happens when facultative anaerobe exhaust/deplete the oxygen?
nothing; they can use oxygen when it’s present, but they can also grow when oxygen isn’t present
what type of organism grows in 5 degrees Celsius, pH 4, and no light (and no oxygen)
acidophiles
how can you slow down the growth of a microbe?
putting it in the fridge
What happens to cell without LPS if you fail to add iodine to gram stain?
The cell will appear pink because there was no iodine to make the purple stay in place; so the purple crystal violet was all washed out with ethanol and then everything was stained pink when safranin was added; false gram negative stain
Which organism does not have a cell wall?
mycoplasma
major characteristics of the three domains:
histone
chromosome
cell wall
cell shape is made/maintained by which enzyme?
MreB protein provides an internal structural support framework
FtsZ directs cell wall formation during cell division
bacteria have cholesterol: T/F?
False
functions of viruses
replicate inside a host cell
have biochemical activity inside a host cell
what is the equation for predicting cell numbers that grow after a certain period of time?
Nt= No x 2^n
No: original population number
n= number of generations in over the time period
Nt= the number in the population at time t
if 2 bacteria cell divide every 30 minutes, how may will there be after 10 hours?
2 x 2^20
What are bacterial microcompartments that contain enzymes involved in carbon fixation?
carboxysomes
What is a polyhydroxyalkanoate (PHA), a polymer belonging to the polyesters class that is bio-derived and is a biodegradable plastic
polyhydroxybutyrate (PHB)
What converts hydrogen peroxide into water and oxygen?
catalase enzyme
a facultative anaerobic and heterotrophic bacterium has depleted its environment of oxygen; what will happen?
the organism will continue to produce ATP via fermentation
beta lactam antibiotics do what?
prevents transpeptidation
found in penicillin, ampicillin, and cephalosporin
thick outer layer of peptidoglycan
- usually gram positive bacteria have a very thick layer of peptidoglycan compared to gram negative; this thick layer contains teichoic acids
- gram neg bacteria have a cell wall made of LPS phospholipid unilayer
lysozyme causes ___ to form in gram positive cells, which causes lysis
lysozyme causes ___ to form in gram negative cells, which can resist osmotic pressure to an extent
protoplast
spheroplast
S-layer
mono-layer of protein that has crystallized, creating an armor for the cell to protect against predation and pH change; usually found in archaea
what domain do methanogens fall under?
archaea; found in human gut
What does UV radiation do if applied on microbes?
damages DNA
A chemical solution is sprayed on a kitchen counter surface. As a result of this treatment, the microbial population on the treated area is reduced by 98%. What is the chemical solution?
disinfecting agent
substrate level of ATP synthesis
obligate aerobes produce ATP via substrate level phosphorylation as they metabolize pyruvate to CO2
Chemical XB4326 is an antibiotic that inhibits the biosynthesis of bactoprenol (flipase) which is found in bacterial cell membranes. you have prepared some bacteriological agar containing this antibiotic and have streaked a strain of Gram + bacteria on this media. Assume that the microbes have all essential nutrients and incubation conditions that are appropriate for their growth, so you’re only evaluating the effect of the antibiotic. What growth results do you expect on media?
in situ, there will be no growth on the medium, thus no gram stain will be able to be perfomed
organism uses CO2 as carbon source; auxotroph for sulfur; in experiments where both CO2 and elemental sulfur are available for the organism, the absence of light makes no impact on its ability to grow; what kind of organism is it not?
phototroph
aren’t harmed by the presence of O2 as they don’t use it
aerotolerant
can use O2 but can also grow w.o it
facultative anaerobes
movement of an organism in response to a chemical stimulus
chemotaxis
single-layer phospholipid, early form of plasma membrane that separated environmental chemistry from inner ribozymes
micelle
membrane water channels that play critical roles in controlling the water contents of cells
aquaporin
membrane transport protein that simultaneously transports two different molecules, in opposite directions, across the membrane
antiport
integral membrane protein that is involved in movement of two or more different molecules or ions across a phospholipid membrane in the same direction
symport
found in human; grows at temperature range of 15 to 40 deg C
mesophile
why did they group archaea and bacteria together?
organisms were separated into prokaryotes or eukaryotes based on the presence of membrane bound organelle structures; only eukaryotes have this so they put archaea and bacteria together
Why did archaea have their own domain and who is responsible for that change?
phylogenetic analysis showed major difference; archaea packs DNA in eukaryotic like manner and they also use histones which bacteria don’t have; their plasma membrane has an ether linkage compared to ester linkage in the other 2 domains; archaea also have NAG and NAT, S-layer, and grow at a much wider range than bacteria; they also have a variety of sizes and shapes; carl woese is responsible for sequencing the DNA of rRNA discovering Archaea is different than bacteria
rapid DNA replication happens in what phase?
log
binary fission happens in what phase?
log
what is complex medium?
unknown composition
Bacteria lack
cholesterol
