Microbiology Exam #1

microbe general definition

microbial cells range from

compared to microbes, viruses may be 10 times smaller

2 characteristics of a microbe

3 exceptions to microbes

super sized microbial cells

microbial communities

living microbial cells

what is a virus

out of the 3 domains, what do microbes associate with more

microbes dont get associated with plants or animals

genome

have the greatest diveristy of genomes

2 importances as to why its good that microbes have the greatest diversity of genomes

2 ways microbes affect food +/-

3 microbial diseases that changed history

built the first compound microscope

first manuscript that illustrated objects under the microscope

coined the term cell

built single lens magnifiers

first to observe single cell microbes

showed maggots in decaying meat were the offspring of flies

showed that a sealed flask of meat broth sterilized by boiling failed to grow microbes

discovered the microbial basis of fermentation

devised swan neck flasks

showed that after boiling the contents remained free of microbes despite access to air

founder of the scientific method of microbiology

devloped pure culture techniques and the petri dish and agar

kochs 4 postulate

introduced the practice of small pox inoculation to europe in 1717

deliberately infected patients with matter from cowpox lesions

practice of cowpox inoculation was called

developed the first vaccines based on attenuated strains

2 vaccines pasteur developed

immunization

discovered penecillium

purified penecillium (2)

the first commercial antibiotic to save human lives

endosymbiosis

studying recently discovered prokaryotes in hot springs

analysis of the 16S rRNA that woese did was that these prokaryotes were a distinct form of life

the prokaryotes found in the hot springs were founded to be

his discovery that replaced the five kingdoms with 3 domains

led to the recombinant DNA

A heat stable DNA polymerase was used for

disproved spontaneous generation

microbes are organisms that include these 6

microbes perform unique roles in geochemical cycling

advances in microscopy and biochem revealed that the structure and function of the various cell components

genome

the first genomes to be sequenced were those of viruses. Whose complete DNA sequence was determined was that of a

bacteriophage

built the first compound microscope

first individual to observe single celled microbes

published a book which illustrated what was seen in the microscope

believed that heat killed microbes when we saw that his teeth were free of microbes after drinking hot coffee

his experiment about keeping meat in a sealed container caused him to argue against spontaneous generation

to disprove spon gen he showed that a sealed flask of meat brother sterilized by boiling failed to grow microbes

discovered cell fission

discovered the fundamental chemical rpoperty of chirality

founded that nutrient substances containing both mirror forms only had 1 form that was fundamental property for life

fermentation

device pasteur came up with

autoclave

showed that repeated cycles of heat was necessary to eliminate spores formed by bacteria

used medical statistics demonstrate the significance of mortality due to diseases

theory that many diseases are caused by microbes

first to determine that a specific microbe causes specific disease

koch demonstrated an important principle of epidemiology

a culture grown from a single parental cell

due to this surgeon fully aseptic environments for surgery and treatments for wounds

made his staff wash their hands with an antiseptic agent after dissecting cadavers

founded penicillin

molecule that killed microbes alone and leaving their host unharmed

(2)purified penicillin and made it the first commercial antibiotic to save lives

chemolithotrophs

use of selective growth media that supports certain classes of microbial metabolism while excluding others

nitrogen fixation

first developed a system of enrichment culture

polyphyletic

recognized that microbes constitute a form of life distinct from animals and plants

transformation

DNA sequencing

restriction endonucleases led to recombinant DNA

restriction endocleases

how to make recombinant DNA

gene regulation discovered in bacteria provided models for animals and plants

recombinant DNA

3 ways of cell transports

what 3 characters are need to go through passive diffusion

transporters pass material into/out of the cell

pumps use energy such as ATP to

Generation of proton motive force

what 2 things work against the proton motive force

PMF is used to create ATP

cell walls peptides can form cross bridges connecting the parallel glycan strands

the bacterial wall is made up of these 2 long polymers

4 characters of a gram positive envelope

Capsule
s layer
gram positive is made up of

5 characters of gram negative envelope

the outer mem of the outer leaflet only of a gram negative envelope is made of

the thin cell wall of a gram negative envelop is made up of

3 bacterial cytoskeleton

cytoskeleton forms a coil inside rod shaped cells

Forms a z ring essential for cell separation

curves inner side of crescent shaped bacteria

3 characters of bacterial nucleioid

single loop of double stranded DNA from a bacterial nucleoid is compacted via supercoling

gene expression in bacterial cells processes occur simultaneously

3 steps of cell division of bacteria

as the cell elongates as it grows in bacteria cell division it adds a new wall at cell equator

when DNA replicates in bacteria division
DNA replicates bidirectionally and begins next rep before cell divides

carboxysomes fix carbon and use energy to make sugar

phycobillisome proteins collect light energy in cyanobacteria

4 storage granules of bacteria cells

2 characters of gas vesicles

reason to orient the cell along magnetic field line for magnetotaxis

4 characters for cell attachment

pilin

stalks that are attached to cells surfaces are

5 reason bacteria build pili

flagella rotate to propel cell
proton passage drives rotation CW or CCW

peritrichous

polar

lophotrichous

attractants cause CCW rotation

repellents to cell cause CW rotation

change of direction

runs and tumbles cause random walk

attractant concentration increases and prolongs run

when bacteria divide by binary fission

these 2 are used for attachments

2 uses of flagella

3 fundamental traits of prokaryotes

function of the outer envelop of the bacterial cell

have very little noncoding DNA

the coordination of the prokary cell enables high reproductive rate

the cytoplasm is contained by the

the cell membrane is composed of

the cell wall of a bacteria extends within the

an aqueous layer that contains proteins such as sugar transporters

what 2 things lie on the outer membrane of the cell wall

a class of lipids attached to long polysaccharides

the  bacterial cell wall and outer membrane constitute the

the lipopolysaccharides and other polysac can generate a thick

cell wall of protists is called

the pellicle of the fungus consists of

4 chemical components all cells share

a major class of organic cations

molecules with multiple amine groups that are
+ charged and neutral PH

total proteins encoded by a genome capable of expression in the cell

created the first protein catalog of E.coli using 2D gels

are protected by a thick cell envelope

this maximizes reproductive potential with minimal resources

the bacterial cell gene expression occurs all at once, for example as the mRNA is being made ribosomes are at the same time making proteins

3 ways to study functions of ribosomes by isolation and analysis of their parts

enables isolation of cell parts so we can study their form and function

by x-ray crystallography and related methods reveals the form of cell components

dissects the function of cell components based on construction of mutant cells with altered functions

4 ways to isolate parts of the cell

general term for the contents of a broken cell

the rate at which particles of a given size and shape travel to the bottom of the tube under centrifuge force

limitation of subcellular fractionation

crystallographic analysis applies only to isolated particles and under conditions in which its full function cannot be observed

limitation of crystallography

shows which genes and proteins are responsible for functions of subcellular complexes

2 functions of the cell membrane

the phospholipid has a hydrophobic tail and a hydrophilic head

phospholipid structure consists of these 3

the 2 layers of phospholipids in the bilayer

3 functions of membrane proteins

membrane proteins form secretion complexes to export toxins and cell signals across the envelope

proteins embedded within the membrane must have a hydrophobic portion that is soluble within the membrane

pressure on cell membrane resulting from osmosis

small uncharged molecules such as gas and water examples of diffusion

membrane permeant weak acids: cross uncharged then bound/unbound to an open H+, this causes acid or alkai stress

key substances in cellular metabolism are

protein enable transport that is highly selective and will only transport certain nutrients and ions under different environmental conditions

organisms that live in complex changing environments express numerous transporters

the ion gradient (ratio of conc) across the cell membrane can store energy obtained from metabolizing food from photosynthesis

hydrogen ion gradient plus the charge diff across the membrane form

proton potential (proton motive force) drives the membrane bound

phosphoryl head groups carry a net charge of negative, thus they are called

the negatively charged phosphatidate could contains various organic groups  such as glycerol to form phosphatidylglycerol

some phospholipids can have positively charged heads such as phosphatidylethanolamine

2 examples of locations of + phosphoryl heads

what are terpene derivatives and their function in the membranes

in eukaryotic membranes the terpene derivatives are

bacteria's membranes are stiffened by pentacyclic hydrocarbon aka

terpene derivative found in archael hydrocarbon chains are

terpenoids are polmeric structures derived from

in this structure to stiffen membranes, every 4th C extends a methyl branch

the branches from the terpenoids strengthen the membrane by limiting movement of hydrocarbon chains

ether linked lipids

ester linked lipids

the terpenoids cyclize to form cyclopentane rings which stiffen the mebrane to a greater extent

the cell membrane consists of phospholipid bilayers containing hydrophobic membrane proteins

3 examples of cell mem protein functions

the bacterial cell wall

the cell wall 2 functions

consists of a single interlinked molecule that encloses the entire cell

a polymer of peptide linked chains of amino sugars

peptidoglycan aka

glycan chains are linked by peptide cross bridges

the cross linked peptides of neighboring glycan strands form the cage of sacculus

have a thick cell wall with multiple layers of peptidoglycan, interpenetrated by teichoic acids

have thin cell walls enclosed by an outer membrane

the peptidoglycan in gram + is reinforced by

teochoic acids can be made up of these 2

outside the cell wall of the gram + is often encased in

an additional layer found in gram  + and as well as archae

is a crystalline layer of thick subunits consisting of proteins or glycoproteins

loss of trait occurs in th absence of selective pressure for genes encoding the trait

the inward facing leaflet on the outer cell mem has a phospholipid composition similar to

lipoproteins are found where

major lipoprotein

the outwater facing leaflet on the outer mem consists of a special kind of phospholipid called

endotoxin

in lipopolysaccharides the fatty acids are esterified to glucosamine

an amino augar found in peptidoglycan and the outwater facing leaflet on the outer mem

two glucosamine dimers each condense with 2 fatty acid chains which makes 4

1 of the glucosamines on the outward facing leaflet is attached to

sugar chain that extends outside the cell

the core polysaccharide extends to the

a chain with 200+ sugars

the outer membrane may contain unique proteins that are not found in the inner membrane vice versa

outer membrane proteins of pathogens are important targets for vaccine development

these permit the entry of nutrients such as sugars and peptides

outer membranes contain a class of transporters called

the outer membrane porins have a distinctive cylinder of beta cheets known as a beta barrel

cells express different outer membrane porins under different environmental pressures

the region between the inner and outer membrane of gram - defines a seperate membrane bound compartment called

this found in gram - contains specific enzymes and nutrient transporters for found within the cytoplasm

eukaryotic microbes that dont have a cell wall possess a

function of contractile vacuole

is highly porous but can prevent phagocytosis and phage infection

the s layer in archaea function

a capsule can be found in both gram +/-

2 function of gram - outer mem

the envelope layers of this outer membrane include protein pores and transporters of various selectivity

important function of cell envelope in bacteria

the DNA organized in loops in bacterial cells

the domains of a bacterial cell connect back to a central point called

3 in bacterial DNA replication

supercoiling (think of a phone cord) becoms compact

mRNA strands dotted with ribosomes

enzyme complexes that help fold the new peptide into its functional tertiary structure

as translation begins the signal sequence binds to a

an RNA protein complex

SRP complex function

in prokaryotes its circular chromosome replicates at the origin but from both sides

the replication fork is propagated by

helicase function

primase fucntion

the complex of DNA polymerase with its accessory components

the DNA termination site triggers growth of dividing partition of the envelope called

the process by which septum occurs in cell division

the process of septation generates most of the new cell envelop to enclose the expanding cytoplasm

look at septation of bacteria

normal division of bacteria doesnt always occur, assymetrical cell division gives rise to

inert endospore is capable of remaining dormant but viable for years

are microscopic membrane bound crystals of magnetic mineral magnetite

magnetosomes generate a magnetic dipole moment along the length of the bacterium which causes it to swim along the magnetic orientation

magnetosomes are anaerobces, and swims downward toward magnetic north

the ability to attach a substrate

the most common structures that bacteria use to attach a substrate is

straight filaments of protein monomers are called

serve to attach a male donor cell to a female recipient cell for the transfer of dna

stalk's tip secretes an adhesion factor called