Prokaryotes Flashcards
What are the three points of cell theory?
all organisms are composed of one of more cells, cells are the monomer for any organism, new cells arise from pre-existing living cells
What the the three types of prokaryotes?
Bactera, Archea, cyanobacteria
Does prokaryotic DNA have histones?
No
Does transcription and translation happen at the same time in prokaryotes?
Yes
What feature allows transcription and translation to happen at the same time?
Polyribosome actvity
What is a plasmid?
circular piece of double stranded DNA smaller than bacterial ribosome. It is considered extrachromosomal
What is conjugation?
Ability for plasmid to orchestrate bacterial exchange of information
How does the prokaryote membrane prevent lysis?
By continually pumping ions across cell membrane increasing osmotic pressure
What is the cell wall of prokaryotes made out of?
peptidoglycan
What is peptidoglycan?
Makes up bacterial wall membrane. Has chains made of sugars and amino acids.
When lysozyme destroys peptidoglycan, what results?
protoplast
What is gram positive bacteria?
thick peptidoglycan layer outside cell membrane and no other layer
What is gram negative bacteria?
thin peptidoglycan but additional layer with lipopolysaccharide
What is the periplasmic space?
space between cell membrane and outer layer
Which has greater resistance to antibiotics, gram-negative or gram positive?
gram negative
What are endotoxins?
In gram-negative bacteria, it is a normal component of outer cell membrane that is not poisonous but causes the immune system to have extreme reaction that can kill us
What is septic shock?
when aqueous portion of blood leaks into tissues causing a drop in blood pressure
What are exotoxins?
toxic substances secreted by gram negative and gram positive into medium. It helps bacteria compete for resources
What is glycocalyx?
a substance that surrounds bacteria. It makes bacteria hard to eliminate and enables bacteria to adhere to smooth surfaces such as the respiratory tract
What is a monotrichous flagella?
flagella at one end
What is a amphitrichous flagella?
Flagella at both ends
What is peritrichous flagella?
Multiple flagella
What are the three parts of the flagella?
filament, hook, and basal structure
What is the basal structure in flagella?
has rings that anchor the flagella to membrane in gram negative bacteria. It rotates rod and rest of flagella clockwise
What energizes the rotation of flagella?
ATP supplied by diffusion of H+ gradient by electron transport
What is chemotaxis?
process of bacterial motion directed toward attractants
What receptors influence flagellar rotation?
chemoreceptors
What are pili?
projections on bacterial surface involved in attaching to diff surfaces
what is function of sex pilus?
facilitates formation of conjugation bridges
A F+ denotes what about the sex pilus?
It is male
A F- denotes what about the sex pilus?
It is female
What do autotrophs use for nutrition?
CO2
What do heterotrophs use for nutrition?
Organic nutrients
What do chemotrophs use for nutrition?
energy from chemicals
what do phototrophs use for nutrition?
energy from light
What are the four types of bacteria?
chemoautotrophs, chemoheterotrophs, photoautotrophs, and photoheterotrophs
What do chemoheterotrophs use for nutrition?
organic molecules made by other organisms
what do photoautotrophs use for nutrition?
use CO2 as carbon source and obtain energy from the sun
What do photoheterotrophs use for nutrition?
get energy from sun but require an organic molecule made by another organism as carbon source
What do chemoautotrophs use for nutrition?
build macromolecules from CO2 using chemicals. They oxidize inorganic molecules
What is an auxotroph?
bacteria that cannot survive on minimal medium because it can’t synthesize a molecule it needs to live. It requires an auxiliary trophic substance to live.
What is an auxiliary trophic substance caused by?
from a mutation in a gene coding for an enzyme in a synthetic pathway
what are obligate aerobes?
bacteria that require oxygen
What are anaerobes?
bacteria that do not require Oxygen
What are facultative anaerobes?
Use oxygen when it is around but does not need it
What are tolerant anaerobes?
can grow in presence or absence of oxygen but do not use it in metabolism
What are obligate anaerobes?
poisoned by oxygen because it lacks enzymes for detoxification of radicals. They often infect wounds
What enzymes do obligate anaerobes lack?
dismutase and catalase
What is distinctive about anaerobic respiration?
It uses an external electron acceptor other than oxygen
Do prokaryotes undergo mitosis?
No
What is the lag phase in bacterial growth?
Prior to exponential growth, cell division does not occur even if growth conditions are ideal. dNTPs are being made
What are the three phases to bacterial growth?
lag phase , exponential phase, stationary phase
What happens in stationary phase?
Bacteria ceases to divide due to lack of nutrients
What is carrying capacity?
max population of bacteria at stationary phase
What is endospore formation?
Formed under unfavorable conditions. Still metabolically active. Only one spore per cell
What is germination?
metabolic reactivation of endospore
What are the three mechanisms of genetic exchange between bacteria?
transduction, transformation, and conjugation
What is transduction?
lysogenic cycle. Employs use of lysogenic phage
What is transformation?
pure DNA added and bacteria internalizes it
What is conjugation?
Bacteria makes physical contact and forms a bridge. F+ reaches out to F- to become F+
What is the frequency of recombination with F+ cells?
High frequency recombination
What is conjugation mapping?
Analyze the recipient of cells in conjugation to see what was transferred
If a parasitic bacteria is obligate where is it located on the cell?
Only inside the cell
If a parasitic bacteria is facultive where is it located on cell?
Inside or outside cell
If a bacteria is symbiotic, what does this mean?
It coexists with the host and derives a benefit
What is chitin of fungi?
rigid cell wall different from plant and bacterial cell wall but found in exoskeleton of insects
What kind of trophs are fungi?
chemoheterotrophs
What kind of fungi feed off of dead plants and animals?
Saprophytes
What kind of fungi feed off living organisms?
Parasites
What kind of fungi have a symbiotic relationship where both organisms profit?
Mutualists
What is the method of nutrition in fungi?
absorptive
What is a hypha in multicellular fungi?
long filament of cells joined end to end
What is septate hyphae?
cells separated by walls called septae
What are aseptate hyphae?
cells joined together in a long tube, in which cytoplasmic contents and nuclei are shared among cells making hypha
Are Fungi multinucleate?
Yes
What are haustoria?
hyphae that are specialized to digest and absorb nutrients in parasitic fashion
What is a myecelium?
meshwork of hyphae
What is a thallus and its components?
large fungal structure. It has a vegetative portion and fruiting body
What is the function of the fruiting body in thallus?
functions in reproduction making spores
