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Three common shapes of prkaryotic cells
coccus (spherical)
bacillus (rod-shaped)
Functions of a cell wall
maintains shape, protects cell, and prevents it from bursting in hypotonic environments
how do cell walls of eukaryotes differ from those of prokaryotes
chiefly, in what they are composed of. in plants and fungi, the cell wall is made of cellulose and chitin, respectively. in prokaryotes, the wall is composed of a sugar-polypeptide polymer called peptidoglycan
Provide a brief overview of Gram-staining.
The sample is washed with crystal violet and iodine, then alcohol, then a red dye such as saffarin. in Gram positive bacteria, the alcohol is unable to wash the violet bye from behind the cell wall (peptidoglycan). In Gram negative cells, the walls are much more complex, with a lipopolysacharride (carbohydrates + lipids) outer membrane and little peptidoglycan in the middle, the dye is washed out and red remains.
What are some complications (for us) resulting from the lipopolysacharride outer coating of Gram negative bacteria?
In many species, it is toxic and causes fever and shock. It also helps to impede the bodys defenses and entry of drugs.
Sticky, outer covering of many prokaryotes
it enables many prokaryotes to stick to substrate, host, or other members of a colony. It can protect against dehydration or the immune system in parasitic species.
Prokaryotic, hair-like appendages
hair like appendages enabling prokaryotes to stick to the substrate/each other
the appendage used in prokaryotic conjugation
pilus (pili plural)
attaches one cell to the other, allowing the transfer of genetic material
directed movement away or toward a stimulus
common structure enabling prokaryotic movement
compare and contrast prokaryotic and eukaryotic flagella
prokaryotic flagella are smaller, not covered by an extension of the plasma membrane, and operate differently. in prokaryotes, the movement is fueled by energy resulting from a proton gradient. they apear to have evolved from an secretory structure.
what are the key differences between prokaryotes and eukaryotes concerning their internal structure and DNA arrangement
Prokaryotes lack the compartmentalization of eukaryotic cells, they have no membrane bound organelles. Some do, however, have specialized membrane infoldings (aerobic for cellular repiration and thylakoid for photosynthesis). In most prokaryotes, the genome consists of a circular chromosome with much less material than linear chromosomes of eukaryotes. Their DNA is found in the membrane-less nucleoid region. They might also have small rings of self replicating dna called plasmids.
a quck form of prokaryotic reproduction
binary fission
some bacteria can withstand harsh conditions by making these
the bacterium produces a copy of its chromosome and surrounds it with multiple tough layers, removing water. these can even survive boiling water and lie dormant for many years
3 important advantages of prokaryotic cells
they are small, they reproduce via binary fission, they have short generation times allowing for quick mutation
what is responsible for genetic variety in eukaryotes vs. prokaryotes
in eukaryotes, it is the genetic reshuffling during meiosis and fertilization. in prokaryotes it is their short life span combined with relatively high mutation rates
What are the three forms of genetic recombination in prokaryotes?
a prokaryotic cell takes up genetic material from its surroundings, incorporating it into its genome
the introduction of new genetic material into the genome faciliated by a bacteriaphage
the exchange of material between two individuals via a pilus

The piece of DNA/plasmid coding for fertility or ability to form a pilus
f factor within an f plasmid
what are the differences in conjugation when the f factor is in the f plasmid vs in the chromosome
when the f factor is found in the f plasmid, the result is a copy of the f plasmid in the receptor cell.
when the f factor is incorporated in the chromosome, the f factor is copied to the receiving chromosome, usually with some additional homologous DNA
facotor for resistance
r factor
sometimes found in the r plasmids
must use oxygen for cellular respiration
obligate aerobe
poisoned by oxygen
obligate anaerobe
anaerobes that can use oxygen for cellular respiration
facultative anaerobes
conversion of atmospheric nitrogen to ammonia (NH3)
nitrogen fixation
example of a colonial cyanobacteria that performs nirogen fixation exclusively.
surface coating colonies of prokaryotes
remember that they utilize channels to deliver nutrients and get rid of waste
they get their energy from light and nutrients from non-organic compounds
they get their energy and nutrients from inorganic chemicals
get their energy from light and nutrients from organic materials
get their energy and nutrients from organic compounds
halophiles and thermophiles
love heat and salt, respectively
archaea that release methane as a byproduct of their metabolism

oobligate anaerobes
example of alpha proteobacteria
rhizobium (lives in roots)
example of betaproteobacteria
nitrosomonas (nitrogen fixing)
example of gamma proteobacteria
example of delta proteobacteria
chondromyces crocatus
example of epsilon proteobacteria
gram positive bacteria
prokaryotes function  as decomposers. others convert atmpospheric materials into a form that can be used by others
who are the two organisms partaking in symbiosis and whate are its three formsq
the host and symbiont
mutualism both benefit
commensalism one benefits, other is not harmed
parasitism one benefits, the other is hurt
parasites that cause disease are known as pathogens
toxic proteins secreted by some pathogens
lipopolysacharride components of the outer membrane of gram-negative bacteria. they break down after death and poison the host
using prokaryotes for pollutant removal
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