Unit one Flashcards
What organisms were the first with photosynthesis and what happened as a result of this
cyanobacteria but the oxygen they gave off was pollution for the organisms thus caused a mass extinction
What organisms are archaea closest related to
eukaryotes which come from the fusion of bacteria and archaea
what advantage and disadvantage do eukaryotes have over prokaryotes
eukaryotes are much larger and structurally complex but has simplistic biochemical capabilities.
What advantage and disadvantage do prokaryotes have over eukaryotes
prokaryotes are much more inventive (can go through any chemical reaction that is favorable) but do not have the energy to become more diverse due to lack of mitochondria
How do prokaryotes obtain energy
proton motor force
Explain the relationship between wolbachia and insects
2/3 of insects are infected with wolbachia (bacteria) which have developed the ability to take in sugar (from sap) and make amino acids for the insects
How does a higher SA:vol ratio help bacteria
allows better exchange of nutrients and replicate faster
How do bacteria affect global climate change
marine algae produce large amounts of DMSP when stressed by UV rays; this causes DMS to be broken down by bacteria which contributes to cloud formation covering the sun making less UV rays
What do cocci look like
spheres
what do clusters look like and how do they divide
resemble grapes and divide in any plane
what do chain of cocci look like and how do they divide
like chains of cocci and can divide on only one plane
what do micrococcus look like and how do they divide
like tiny grapes and can divide in two planes
what do diploccoccus look like
two balls
what are bacillary look like
rods
what do coccobacillus look like
a mix between rods and coccoid
what do curved rods look like
worms
what do spiral bacteria look like
corkscrews
what do caulobacter crescentus look like
a bean split in half long ways and one side with a rod used to get nutrients and the other with flagella used for movement
what are mycoplasms and how do they look
cell that lost the ability to from cell walls; look like vases
describe the membrane of bacteria
fatty acid chain that is nonpolar and hydrophobic and phosphate that is polar and hydrophilic
what is most of the bacterial membrane made of
2/3 protein that is mainly used for energy or transportation
what does cholesterol do to the membrane and what bacteria have it
alters fluidity and is only found in mycoplasm and methylotrophic bacteria
what do hopanoids do to bacteria
strengthen the membrane
what are the differences in the plasma membrane for arhaea and bacteria
bacteria use ester linkages between their glycerol and fatty acids; compared to the ether linkages in archaea they are less stable making them more susceptible to hydrolysis
Why are the linkages in the plasma membrane of archaea more stable than in bacteria
The linkages use phytanyls instead of fatty acids and have cyclopentane rings
What are the function of microcompartments
to retain volatiles like CO2
How does a carboxysome work
Bicarbonate is brought into the cell which is then made into CO2 by Carbonic anhydrase; the CO2 is then turned into its organic from
What is another function of carboxysome
to keep O out so that is isn’t used with rubisco to produce wasteful products
what is a paralog and how is it advantagous
occassional duplication of a gene which can create novel functions
How is DNA stored in prokaryotes
it is semi-condensed by being wrapped around proteins or histones for archaea
How does DNA gyrase work
makes negative supercoils by cutting DNA passing one through the other and then resealing it; works ahead of DNA replication as that creates positive supercoils
What con comes from DNA gyrase
It condenses DNA making it hard for it to be transcribed so only infrequently DNA is supercoiled while frequently used DNA is left on the ends to be transcribed
How can DNA gyrase be used to fight off prokaryotes
DNA gyrase is only found in prokaryotes so antibacteria medicine can target it
What are the two types of bacteria and how are they different
gram positive which have a lot of peptidoglycan in its cell wall and gram negative which have little peptidoglycan but a periplasmic space and an outer membrane
Which type of bacteria can control its chemical composition of its periplasmic space
gram negative bacteria
What is peptidoglycan made of
glycan and a peptide. The glycan alternates between NAM and NAG linked by a beta 1,4 linkage and the peptide is made of four amino acids
What is the difference between NAM and NAG
NAM is able to bind to a lactic acid and is exclusive to bacteria.
What are the four amino acids in peptidoglycan
L alanine, D glutamic acid, D alanine and DAP which can form an extra peptide bond to increase structural integrity
What type of bacteria is DAP exclusive to and what does the other type of bacteria use
DAP is exclusive to gram negative bacteria while gram positive bacteria use lysine
How does cross linking happen with peptidoglycan
Gram positive bacteria use an interbridge made of glycines that uses sortase while gram negative bacteria creates direct crosslinks
What is psuedopeptidoglycan
found in some archaea that uses NAG and TAO and only uses L forms
What is the use of cycloserine
Can be used agaisnt peptidoglycan synthesization in which it prevents the converting of L alanine to D alanine and connections between D alanine and L alalnine
How do our bodies’ innate defense system fight bacteria
TLRs are used to recognize peptidoglycan and other MAMPS which will cuase a phosphorylation cascade that releases a cytokine gradient that white blood cells will follow
What are beta lactams and how do they work
antibiotics that stop peptidoglycan synthesization by inhibiting the cross linking of peptidases via inhibiting transpeptidases
How does vancomycin prevent cross linking
binds to peptides as they cross the cell
what type of bacteria are resistant to vancomycin and why
gram negative bacteria since the vancomycin is too large to cross the membrane
What type of bacteria are resistant to beta lactams and how
Gram negative bacteria which have beta lactamase that break down beta lactam rings making it so that they can’t bind to transpeptidases
What is teichoic acid
molecule that when in the membrane of only gram positive bacteria gives them greater stuctural strength
What is Braun’s lipoprotein do
Connects peptidoglycan and outer membrane in gram negative bacteria; without it the outer membrane would drift away
What are a signature molecule of gram negative bacteria
lipopolysaccharides (LPS) which introduces cytokines and is involved in the immune system and can take out worn proteins via vesiculation
what does the membrane of mycobacterium look like
gram positive bacteria
What makes it hard to stain mycobacterium
Arabinan that gives the cell a waxy coating making it hydrophobic
What are capsules
type of glycalyx that is important for virulence as it makes bacteria too slimy for phagocytosis
How do capsules help bacteria during hard environmental times
keeps it hydrated, excludes toxins and viruses, and can be used as an energy source
what is the griffith experiment
When S. pneumonia was grown in agar it would from a capsule that killed mice however a mutation occured that resulted in no capsule that would not kill mice. When dead capsules were injected alongside the mutations the mice would die giving rise to the idea of transformation
What are fimbriae
numerous short appendages used to help bacteria adhere to receptors and movement
What are pili
long rod-like extensions that an be used for DNA exchange; usually only one or two on a cell
How are pili used for DNA exchange
they connect the cytoplasms of cells and pull them together
what are polar bacteria
monotrichous or one flagella
what are peritrichous bacteria
flagellum all over the place
what are amphotrichous bacteria
flagellum at each pole
what are lophotrichous bacteria
tuft of flagella are one pole
What are the three structures of flagellum and what do they do
filament: drives motility
hook: attaches basal body to filament
basal body: has four rings in gram negative and two in gram positive
What is a mot protein
protein in flagellum that covers the two lower rings of the basal body and drives rotation via PMF
what rings in flagellum are used in the outer membrane and peptidoglycan
L ring for the outer membrnae and P ring for peptidoglycan
What are the two rings present in both types of bacteria
C ring that is in contact with the cytoplasm and MS ring that spans the membrane
What way do flagellum spin to create movement vs tumbling
counter clockwise for movement and clockwise for tumbling
what are spirochetes
bacteria in a corkscrew shape that move vial axial filaments
How do bacteria/archaea sense concentration gradients
MCPs that are bound by repellants and attractants which cause phosphorylation of protiens when not suppressed by an attractant
What is the process by which bacteria continue movement
When attractants bind to MCP CheA remain unphosphorylated; but if left unphosphorylated for too long CheR adds methyl grops to MCPs which will cause CheA to be phosphorylated
What is the process for bacterial tumbling
When an MCP is not activated CheA will autophosphorylate causing CheB and CheY to be phosphorylated. the phosphates from these are transferred to the basal body to trigger tumbling. CheZ will then take phosphate off of CheY to stop tumbling
What does CheW do in chemotaxis
connect the MCPs to allow for communication
What is the type one secretion pathway
protein is made in the cytoplasm, it binds to proteins in the cytoplasmic membrane, those proteins will hydroyze ATP and the protein will be transported through TolC
What are the restrictions of the type one sectretion system
only used for gram negative bacteria and cytoplasmic membrane proteins are only for specific proteins
What is the sec dependent pathway
Ribosome translate mRNA into a protein, protein is accompanied by two chaperone proteins to prevent protein folding, chaperone proteins brng protein to translocon, secA pushes protein across secYEG, signal sequence is cleaved off protein
What are the restrictions of the sec dependent pathway
only works with unfolded proteins and if in gram negative bacteria another process is needed for outer membrane
what is the process of type 2 protein secretion pathway
ATP is hydrolyzed to secrete proteins across the membrane and pseudopilus extend to push molecues out of the cell then contract back via ATP hydrolysis
What are the restictions of the type 2 protein secretion pathway
only in gram negative bacteria, uses many proteins, and only uses folded proteins
What is the type six secretion pathway
Hollow protein is loaded with toxins and effectors (change physiological shape) and put inside of the Hcp tube which is a hollow tube on the inside of the sheath. the sheath extends then pushes the Hcp tube out to release the toxins
What are endospores
bacteria built to survive in feast or famine enviroments
What characteristics make endospores great at surviving
has multiple coats, high amount of peptidoglycan, pumps water out, SASPs bind DNA to prevent radiation
How do endospores from
cell becomes a cannibal once it senses lack of food, DNA is replicated and highly condensed via SASPs, water is actively pumped out and coat layers form, vegetative cell disintegrates and spore is released
how are microbes useful in bioremediation
Syntrophy which is when a community of bacteria break one compound into another so another bacteria can break that down so another can break that down and so on
What does photo mean
light energy
what does litho mean
electrons come from inorganic sources
What does autho mean
takes in inorganic CO2 and makes organic molecules
what does chemo mean
uses chemical energy
What does organo mean
electrons come from organic matter
what does hetero mean
uses reduced, preformed organic molecueles
what is simple transport driven by
PMF
What does a symporter do and what type of transport system does it use
moves specific molecules and protons across the membrane, uses simple transport
What does an antiporter do and what type of transport system does it use
brings protons in while exporting cations; can be used to shield cell from antibiotics uses simple transport
What does a uniporter do and what type of transport system is it
transport a molecule but not protons; since molecueles are positively charged there is no need for a proton also reduces charge differential
what is group translocation and where does the energy come from
chemical modification of transported substances (usually sugars); energy comes from phosphorylation event in cell
Why is iron so hard for bacteria to get
It is mostly insoluble in its most abundant form thus unable to be broken down and the iron that humans have is tightly bound to proteins that bacteria cannot reach
What is nutritional immunity
Immunity to bacteria by restricting their access to needed nutrients
How do bacteria get iron
Secreting siderophores into the environment that hunt for iron and hopefully find some bacteria to give the iron to
What are the siderophores of marine bacteria
aquachelin that form a bubble to 7 iron
