Test One Flashcards
what is a microbe
a microbe is a living organism that requires a microscope to be seen
what are some exceptions to microbes not needing a microscope to be seen
some protists, some algae, some bacteria
what is the avg range size for microbial cells
millimeters to .2 micrometers
what are some contradictions to the microbe definition
supersize microbial cells
microbial communities
viruses
what domains of life will you find microbes
bacteria, archaea and eukarya
what are the three domains of life
bacteria, archaea and eukarya
prokaryotes lack a
nucleus
what is a genome
total genetic information contained in an organism’s chromosomal DNA
who developed the first method of DNA sequencing
Fred Sanger
in the 70’s
what was the first genome sequenced according to the book
bacteriophage (virus)
1977
what was really the first genome sequenced
RNA virus in 1976
when was the first genome of cellular microbe sequenced
1995
what was the first genome sequenced of a cellular microbe
Haemophilus influenzae
what microbial disease was big in the 14th century
bubonic plague
what microbe causes the bubonic plague
Yersinia pestis
what transmitted the bubonic plague
rat flies and prairie dogs
what microbial disease was big in the 19th century
tuberculosis
what microbe causes tuberculosis
Mycobacterium tuberculosis
what microbial disease was big in the 20th-21st century
AIDS
what causes AIDS
HIV
more soldiers have died of what than of wounds in battle
microbial infections
who first recognized the significance of disease in warfare
british nurse
florence nightingale
florence nightingale founded what
science of medical statistics
“polar area chart”
what does medical statistics show
shows the deaths of soldiers due to carious causes
how were microbes discovered
by chance
who built the first compound microscope
robert hooke
what is a compound microscope
two lenses lined up, increase magnification beyond magnifying glass
what did robert hooke use the compound microscope for
mold filaments
who published micrographia
robert hooke
what was in micrographia
the first manuscript that illustrated objects under the microscope
who coined the term cell
robert hooke
what was the magnification of a compound microscope
30x
how did robert hooke define cell
distinct units of living material
who worked as a cloth draper
antonie van leeuwenhoek
who built single lens magnifiers
antonie van leeuwenhoek
what was unique about the single lens magnifiers
there was a sample holder and focus adjustment
who was first to observe single celled microbes
antonie van leeuwenhoek
how did antonie van leeuwenhoek observe singel celled microbes
examined matter between teeth before and after drinking hot beverages
first dentist
what did antonie van leeuwenhoek call single celled microbes
small living animals
who is credited for looking at noted cases of microbes associated with pathology fungal disease in silk worms
agostino bassi de lodi
what helps differentiate human tissue from microbial cells
differential chemical stains
what was a finding that agostino bassi de lodi discover
hard to distinguish between microbes and single celled components of the human body
couldnt distinguish healthy from disease tissue
what is spontaneous generation
the theory that living creatures could arise without parents
was francesco redi for or against spontaneous generation
against
what was Francesco redi’s experiment
sealed meat and no maggots were observed
no flys means no maggots
what was odd about francesco redis experiment
meat still produced microbes, this went towards spontaneous generation
what was lazzaro spallanzani experiment
sealed flask of meat broth sterilized by boiling failed to grow microbes
what was lazzaro spallanzani view of spontaneous generation
argued against
from lazzaro spallanzani experiment, what did he observe
microbes appeared paired
“cell fission”
louis pasteur discovered what
the microbial basis of fermentation
pasteur thought fermentation was caused by
yeast
what was pasteurs idea of fermentation
yeast produces alcohol, when yeast culture is contaminated with bacteria, the bacteria outgrow the yeast and produce acid instead of alcohol
why did some people believe spallanzani experiment produced no microbial growth
not because of boiling but because of lack of oxygen
how did pasteurs experiment test theory of spontaneous growth
“swan neck flask”
even after boiling, no microbial growth even when air is presence
what was the scientist that had experiments to disprove the theory of spontaneous growth
louis pasteur
who attempted same pasteur experiment but received different results
john tyndall
in john tyndall experiments, what did he discover
endospores
resistant to heat and boiling
what is germ theory of disease
diseases caused by microorganisms
who was the founder of scientific method of microbiology
robert koch
who studied anthrax (cattle epidemics)
robert koch
how did robert koch study anthrax
took infected carcus samples and inject into rabbit and rabbit dies
what is chain of infection
transmission of disease
who demonstrated the important principle of epidemiology: the chain of infection, or transmission of disease
robert koch
what is a pure culture
one type of organism growing in culture
who used pure cultures to prove a particular bacterium cause a specific disease
robert koch
who created the solid medium, agar for experiments
angelina and walther hesse
what replaced gelatin
agar
who created or used the double dish container, covered glass version of kochs glass dishes, petri dish
julius petri
what is the criteria for establishing a causative link between an infectious agent and a disease
- microbe is always present in diseased host and absent in healthy
- microbe is isolated from diseased host and grown in pure culture
- introduce pure microbe into healthy host, individual becomes sick
- same microbe re-isolated from now sick individual
in the 18th century what children where inoculated with the small pox virus and received mild form of disease then became immune
children in asia/africa
who introduced the practice of small pox inoculation to europe
lady mary montagu
with montagu inoculating children with small pox, was this seen as attenuation
no
who was the first to recognize attenuation
louis pasteur
who infected patients with matter from cowpox lesions
edward jenner
what was the infecting patients with matter from cowpox lesions a practice of?
vaccination
who was the first to develop the first vaccines based on attenuated strains
louis pasteur
what does immunity mean
resistance to specific disease
what does immunization mean
the stimulation of an immune response by deliberate inoculation with an attenuated pathogen
who ordered doctors to wash their hands with chlorine, an antiseptic agent
Ignaz Semmelweis
what is an antiseptic
chemical that kills microbes
did doctors believe that hand washing with chlorine helped lower mortality rates
no
to created carbolic acid to treat wounds and clean surgical instruments bc 1/2 of his amputee patients dies
joseph lister
when was aseptic surgery developed
20th century
environments completely microbe free
who discovered that penicillium mold generated a substance that kills bacteria
Alexander fleming
how was penicillium discovered
by accident, with staph
who purified penicillin
howard florey and ernst chain
what was the first commercial antibiotic to save human lives
penicillin
who studied tobacco mosaic disease
dmitri ivanovsky
how did dmitri ivanovsky study tobacco masiac disease
agent of transmission could pass through a porcelain filter that blocked all known microbes
who worked on the agent of tobacco mosaic disease is not a bacterium because passes through filter that retains bacteria
martinus beijerinck
who was able to purify the filterable agent and crystalize it
TMV: tobacco mosaic virus
Wendell Stanley
what does cultivated mean
brought into pure culture
what is the percentage of microbial species that have been cultured in a laboratory
less than .1%
the remainder of microbes make up the majority of
earths atmosphere
what part of earth supports the complex multicellular life
outer skin of earth
who was the first to study bacteria in its natural habitats
sergei winogradsky
who discovered the beggiatoa oxidizes H2S
sergei winogradsky
who discovered chemolithotrophs (or lithotrophs)
sergei winogradsky
what are lithotrophs or chemolithotrophs
microbes that derive energy from inorganic electron donors
what is an example of lithotrophs or chemolithotrophs
beggioatoa
who developed enrichment cultures
sergei winogradsky
what are enrichment cultures
cultures derived from the use of selective media that support the growth of certain types of microbial metabolism while excluding others
not a pure culture
what is the wetland model ecosystem also called
winogradsky column
who showed the importance of bacteria in geochemical cycling
winogradsky
what is geochemical cycling
global interconversions of inorganic and organic forms of nitrogen, sulfur, oxygen, phosphorous, carbon, etc
what are endosymbionts
organisms living symbiotically inside a larger organism
which microbe is a supersize microbial cell that can be seen by the naked eye
thiomargarita namiiebiensis
what are the two challenges with microbial classification
light microscopy allows little more than visualizing the outward
shape of cells
microbes do not fit in definition of species
how much DNA similarity do 2 distinct species share
no more than 95%
what is the endosymbiosis theory
polyphyletic ancestry of living species
not a common ancestor
advances in biochemistry and microscopy revealed…
the fundamental structure and function of cell membranes and proteins
the revelation of DNA and RNA structures led to the discovery of what
genetic programs of model organisms
what two instruments led to study of cell strucutre
the electron microscope and the ultracentrifuge
who developed the electron microscope
ernst ruska
what can you see using the electron microscope
cytoplasm containing macromolecules
phospholipid membrane
intracellular membranes, ribosomes, mitochondria, chloroplasts
DNA containing nucleoid
who developed the ultracentrifuge
theodor svedberg
what is the ultracentrifuge used for
separates cell components such as proteins
what is transformation
internalization of free DNA from the environment into bacterial cells
what is an example of transformation
dead virulent strain injected into mouse with non virulent strain, DNA mutate into virulent DNA and kills mouse
what is resolution
the smallest distance by which two objects can be separated and still be distinguished
what is detection
the ability to determine the presence of an object
what is magnification
an increase in the apparent size of an image to resolve smaller separations between objects
microbial size of eukaryotes
10 to 100 micrometers
microbial size of prokaryotes
o.4 to 10 micrometers
what is light microscopy
resolves images by absorption of light
what is electron microscopy
uses of beam of electrons to resolve details
SEM and TEM
Xray crystallography
used to build a computational model of the molecular structure
what shape is bacilli
rods
what shape is cocci
spheres
what are the spiral forms of microbes
spirochetes and spirilla
what shape is vibrio
comma shape
what are some fundamental traits of prokaryotes
thick complex outer envelope
compact genome
tightly coordinated cell functions
what would you find in the prokaryotic cytoplasm
water, ions, small organic molecules, have some macro molecules
what will you find in the cell membrane of microbes
phospholipids, transporter proteins, and other molecules
what composes the cell wall of microbes
composed of polysaccharides linked covalently by peptides (peptidoglycan)
what is a flagellum
external helical filament whose rotary motor propels the cell
what is a nucleoid
non membrane bound area of the cytoplasm that contains the chromosomes in the form of looped coils
what is the most abundant component in a cell
water
what is the 2nd most abundant component in a cell
protein then RNA
what is subcellular fractionation
isolate cell parts, separating cell membrane, isolate proteins, isolate DNA and RNA
what is structural analysis
reveal the form of cell components
what is genetic analysis
examining function of cell components
what are ways to study cell parts
subcellular fractionation
structural analysis
genetic analysis
what are some techniques for subcellular fractionation
mild detergent analysis
sonication
enzymes
mechanical disruption
what is mild detergent analysis
lyse cells
dissolve membranes without denaturing proteins
what is sonication
lyse cells with ultrasonic vibrations
help separate proteins
what do enzymes do
lysozyme: breaks down cell wall
what is mechanical disruption
high pressure, bead- beating
use beads to break pellet, friction shears cell membranes, used to shear DNA
crystallography helps relate what to what
structure to function
what is done during genetic analysis
mutant strains are selected for loss of a given function, or a strain can be intentionally mutated so as to lose or alter a gene
definition of cell membrane
the structure that defines the existence of a cell
what is in a cell membrane
phospholipid bilayer containing lipid soluble proteins
what are the 2 main functions of a cell membrane
mediates transport from outside to cytoplasm
carriers proteins with specific functions
what are more function of the cell membrane
structural support
detection of environmental signals
secretion of virulence factors and communication signals
ion transport and energy storage
membranes have equal parts of
phospholipids and proteins
what are the reinforcing agents of cell membranes in eukaryotes
sterols
what are the reinforcing agents of cell membranes in prokaryotes
hopanoids or hopanes
what molecules can DIFFUSE through the cell membrane
small uncharged molecules, water
is diffusion energy dependent or independent
independent
what is osmosis
diffusion of water from regions of high water concentration (low solute) to regions of low water concentration (high solute)
what is required for ions to pass membrane
transporters
what are some transport proteins
channels, pores, passive transport, active transport
what is passive transport
molecules move along their concentration gradient, no energy needed
what is active transport
molecules move against their concentration gradient, requires energy from ATP hydrolysis
may use co transporter
what is another name for the bacteria cell wall
sacculus
most bacterial cell walls are made of
peptidoglycan or murein
what does a molecule of peptidoglycan consist of
glycan linked to peptide of 4 to 6 aa
what makes up glycan
n-acetylglucosamine
n-acetylmuramic acid
peptides form what kind of bridges to connect to parallel glycan strands
cross bridges
where are capsules found
in gram positive, some gram neg and rare in archaea
where are s-layers found
some gram positive and some archaea
what are capsules made of
polysaccharides
what is the function of a capsule
virulence factors, protect from host immune system
why was bacteria first used in determining DNA
faster reproductive times, easy to cultivate
the promise of DNA was first fulfilled in what organism
bacteria and bacteriaphages
what kind of enzyme led to recombinant DNA
restriction endonucleases
finding gene regulation discovered in bacteria provided models for…
animals and plants
what is the s layer made of
made of protein or glycoprotein
function of the s layer
deter predators, contribute to cell shape, protection from osmotic stress, resistant to lytic enzymes, protect from change in pH
what reinforces the cell wall in gram positive
teichoic acid
LPS in gram negative is linked to what
phosphoglucosamine
purpose of gram staining
differentiate gram positive and negative
what can you find in the outer membrane and not inner
sugar binding proteins and porins
what does periplasm contain
transporters for sugars, amino acids, and other nutrients
are archaea pathogens
no
where can you find archaea
open ocean, soil, and surface of plant roots
what is an antibiotic
compounds produced by one microbe that can kill or inhibit the growth of other microbes
what is broad spectrum antibiotic
effective against many species
what is a narrow spectrum antibiotic
effective against few or a single species
example of narrow spectrum antibiotic
penicillin towards gram positive
sources of antibiotic
natural products and artificial means
what is a bactericidal
antibiotics kill target organisms
only affect growing cells
such as cell wall synthesis
what is bacteriostatic
antibiotics prevent growth of organisms
cant kill organism hoping immune system removes organism
what do antibiotics attack
cell wall and membrane
DNA and RNA synthesis
protein synthesis
metabolism
what is the function of cell envelope
contain and protect cells genome
bacterial DNA is organized in loops called
Domains
where would you find domains in prokaryotes
extended throughout the cytoplasm
how many domains do nucleoids form
about 50
what is the central point of the nucleoid
the origin of replication
where is the origin of replication attached at
at cell envelope at the equator
what are supercoils
extra twists in DNA to fit all of the DNA in the cell
what enzyme helps with supercoils
gyrase
how does a supercoil twist
opposes the natural twist of the duplex
what is the name of the supercoil that opposes the natural twist
negative supercoil
what kind of supercoil is in archaeal hyperthermophiles
positive supercoils
keeps coil together in high temps
what kind of supercoil in archaeal mesophiles
negative supercoil
what is transcription
DNA transcribed to RNA by RNA polymerase
what is translation
mRNA binds to ribosome to produce protein sequence
what enzyme is required for ribosome to convert RNA to protein
aminoacyltransferase enzyme
when does translation and transcription occur during bacteria
coupled together during DNA replication
this helps bacteria divide in 10 min
everything occurs in cytoplasm
in eukaryotes when does transcription and translation occur
during interphase when cell is not dividing
things occur in nucleus and then cytoplasm
how does protein synthesis work with prokaryotic membrane
protein synthesis is embedded in lipid membrane, protein synthesis occurs and is secreted out of membrane
what is transertion
coupling of transcription and translation to membrane insertion
how does cell division work in bacteria
bacterial DNA replication is coordinated with cell wall expansion and then separation of two daughter cells
do bacterial cells go through meiosis or mitosis
no
how do bacterial chromosomes replicate
from its origin, bidirectionaly
what helps DNA polymerase in DNA replication of bacteria
replisome
what needs to happen before the bacterial cell can divide
DNA replication must be completed
what triggers the growth of the dividing partition
replication of the termination site
what is another name for the dividing partion in a bacteria cell
septum
how does the septum grow during cell division
grows inward, constricting and sealing off the two daughter cells
what needs to happen in cell division for rod shape bacteria
the envelope needs to elongate prior to septation followed by the formation of a new polar envelope
what is polar aging
bacterial cell poles differ in their origin and “age”
what are some ways bacteria can generate two kinds of daughter cells
one is stationary and other mobile
flagellum to stalk
start with flagellum then stalk and flagellum then separation and one mobile other stationary
is the polar aging in bacterial cells symmetrical or asymmetrical
asymmetrical
do the poles of daughter cells of cell divison differ chemically
yes
how do cells go through septation in spherical cells
parallel planes to make chains
or right angles to make tetrads
what are phototrophs
organisms that use energy from light to carry out various cellular metabolic processes
what protein complexes do phototrophs use to harvest light
contain chlorophylls
what are thylakoids
extensively folded intracellular membranes
invaginations of plasma membrane
what do thylakoids contain
photosynthetic proteins and electron proteins
function of thylakoids
conduct light reaction
photon absorption and energy storage
energy used to fix CO2
what is a carboxysomes
polyhedral bodies packed with enzyme RuBisCO for CO2 fixation
what are some specialized structures of phototrophs
carboxysomes, gas vesicles
phycobilisomes
storage granules
what are gas vesicles in phototrophs
trap H2 and CO2 from cell metabolism to increase buoyancy
what are phycobilisomes
light harvesting antennae
what do storage contain in phototrophs
glycogen, PHB, PHA, and elemental sulfur
what are magnetotactic bacteria
magneticaly directed motility bacteria
bacteria that orient along the magnetic filed lines of the earth
what are magnetosomes
membrane embedded crystals of magnetite or greigite
create dipole moment
orient swimming of megnetotactic bacteria
what is adherence
ability to attach to a substrate
what is motility
ability to move and relocate
what are some structures for cell attachment
pilus, fimbria, sex pili, nanotubes, stalks
what are pili and fimbria
straight filaments of protein monomers called pilin
function of sex pili
used in conjugation to transfer DNA
what are nanotubes
extensions of cell envelope that connect the cytoplasm or periplasm between different cells
what are stalks
membrane embedded extensions of cytoplasm
tips secrete adhesion factors known as holdfasts
how do prokaryotes swim
using flagella
what are petritrichous cells
several flagella randomly distributed around the cell
what are lophotrichous cells
several flagella attached at one or both ends of cell
what are monotrichous cells
have a single flagellum
what are amphitrichous cells
single or tuft of flagella at both ends
what are flagellin
spiral filament of protein monomers in flagellum
what rotates the flagella
the motor driven by proton motive force
functions of flagella
cause population to disperse, decreasing competition
adherence of cells to a substrate to form biofilm
what is chemotaxis
movement of bacterium in response to chemical gradient
either toward or away
attactants cause flagelum to move in what direction
counter clock wise
in flagellum CCW movements, what are runs and tumbles like
long runs with shorter tumbles
repellents cause flagellum to move in what direction
clock wise
what is the overall movement of flagellum
random walk
in flagellum, CW movements have what type of runs and tumbles
more tumbles to shorten runs
runs help move cell
forward
tumbles help cell do what
stop and change direction
are there on or multiple species in a biofilm
one or multiple
where can you find biofilms
organic or inorganic surfaces
when do biofilms form
when nutrients are plentiful
what can cause biofilms to form
environmental signals
pH, iron concentration, temp, O2 availability, amino acids present
how do biofilms attach
flagella, pilip, lipopolysaccharides or other cell surface appendages
what is bad about biofilms
create colonies that are antibiotic resistant and immune system resilient
resistant to phagocytosis
can increase antibiotic resistant gene
how do cells in biofilms create such a barrier
form thick extracellular matrix made of polysaccharide polymer and EPS
what is quorom sensing
how bacterial cells communicate with each other by sending and receiving chemical signals
helps with binding to certain substrate and to each other
