Ch 1: The Microbial World Flashcards
How many cells do microorganisms have
single cell or cell cluster or virus
what are microorganisms
organisms too small to be seen with naked eye
General length of microorganisms
1 mm or less in diameter
what is microbiology
study of microbes + their interaction w/ other living organisms
one way you CAN see microorganisms
petri dish. A bunch of microoganisms
two main themes in microbiology
- nature and function of microbial world
- apply our knowledge to benefit humans
what are 2 patterns of internal structures in organisms
prokaryotes and eukaryotes
Main differences b/w prokaryotes and eukaryotes
- No nucleus in prokaryotes
- no mitochondria in prokaryotes
Common b/w pro and eukaryotes
- cytoplasmic membrane
- macromolecules
- ribosomes for proteins synthesis
- most microorganisms have cell walls for structural strength
Bacteria and archae have what kind of cells
prokaryotes
Protists and fungi have what internal structure
eukaryotes
Which is bigger, prokaryotes or eukayotes
Prokaryotes are smaller ( 0.4 - 10 um) than eukaryotes ( 10-100 um)
How is the genome in prokaryotes
usually single closed circular chromosome
How is the genome in eukaryotes
Its organized into linear chromosomes
what is a genome
on organisms complete genetic content
what kind of genome does E.coli have
typical prokaryotic genome
how many chromosomes are there in human haploid genome contains
23 linear chromosomes
3 properties of all microbial cells
metabolism
growth
Evolution
what is metabolism
all biochem reactions that occur within a cell
What do cells do in metabolism
carry out reactions that supply energy and precursors needed for biosynthesis of cell components
4 Properties of microbial cells
- Differentiation
- communication
- genetic exchange
- motility
early on in earths history, atmosphere lacked _____
Oxygen. Only anaerobes could survive
all cells descended from
a common ancestral cell aka LUCA aka last universal common ancestor
3 major cell lineages arw
bacteria, archaea, eukarya
how are bacteria and archaea distinct
phylogenetically
which domain is archaea closer to
eukarya
how can you determine evolutionary relationships b/w organisms
dna sequence comparing
major groups studied by microbiologists
prokaryotes, eukaryotes, viruses
define population
A group of same species of microbes
define habitat
the immediate environment in which the population exists
what is microbial community
2+ populations coexisting and interacting
what are the major microbial ecosystems
aquatics, terrestrial and higher organisms
whats microbial ecology
study of microorganisms in their natural environments
what are extremophiles? some archaea and bacteria are extermophiles
organisms that grow optimally in chemical or physical extremes
what constitues the major fraction of biomass
microbes
What are pathogens
disease causing bacteria and virus
how are some ways infectious disease are controlled
- increased understanding
- sanitation increase and public health practises
- vaccines
- antimicrobial agents
are most microbes harmful?
no, they are beneficial to humans
In what conditions are infectious diseases still a threat
- in developing countries
- rapid emerging diseases
Where do most microbes reside
marine subsurfaces
What does it mean for an organism to be an extremophile
to be able to grow optimally under various chemical or physical extremes
what kind of processes of microbial organism can alter their ecosystems
metabolic. As resources and conditions may change
What is an ecosystem
includes all living organisms + physical and chemical components of their environments
Can microbial community interactions be beneficial or harmful
both
How is abundance and diversity within a community determined
resources, like food
conditions, like temperature, pH, oxygen etc
what part of the eukaryote domain are microorganisms
fungi
What part of bacteria and archaea domain are microorganisms
All
When comparing DNA sequences of organisms to determine phylogenies, what genes in specific are used
rRNA (ribosomal RNA)
what is the differentiation properties in microbial cells
ability to form new cell structures for growth, dispersal or survival. like spores
Describe the communication property of microbial cells
they communicate thru chemical signals released in the environment
What is genetic exchange property in microbial cells
transfer of genes from cell to cell.
What is the benefit of genetic exchange
quick evolution
What is motility in microbial cells
movement of cells in environment. Like a flagellum
what is the growth property in microbial cells
increase in number of cells over time
What is the evolution property in microbial cells
descent w/ modification w/ genetic variety. This can be rapid
Membranes in eukaryotes and prokaryotes
no internal membranes in prokaryotes. And eukaryotes have membrane bound organelles
where is the genome located in eukaryotes
nucleus
What type of disease are less common today
Infectious diseases are less common. meaning non microbial diseases like heart disease and cancer are more common comparitively
one point on why microorganisms are important for agriculture
the cycling of nutrient by microorganisms is important
Example of crop which used nitrogen fixing bacteria
legumes
what do nitrogen fixing bacteria do
Convert atmospheric nitrogen (N2) into ammonia (NH3)
What macromolecule has nitrogen as a key component
proteins. Note: Legumes are source of protein, hence need nitrogen fixing bactera
What do sulfur cycling bacteria do
Convert toxic hydrogen sulfide (H2S) into sulfate (SO42-), a nontoxic essential plant nutrient
tldr; toxic to non toxic sulfur
Cattle (sheep goats etc) have specialized digestive chambers called
rumen. These animals are called ruminant animals
what is the key feature of the rumen
basically is digests and ferments cellulose – and this is done by microoganisms in the rumen
Why is the digestion and fermentation of cellulose imp in ruminant animals
cellulose is big part of plant cell walls (so basically helps ruminants break out plant cell wells as they eat it)
how is energy in ruminant animals formed
through the microbial fermentation of cellulose — this process produces fatty acids — which is energy
how can microoganisms be harmful to agriculture
cause diseases in plants and animals
example of microbial diseases caused in plants and animals that affects human
E.coli aka salmonella from infected meat
What was the salmonella heidelberg
it was a multidrug resistant salmonella
What happened in the outbreak of salmonella heidelberg
Happened in chicken products in California costco. 100k pounds recalled. 634 people infected
Do humans have cellulose ( imp part of plant cell wall) degrading microorganisms
no
do humans have a rumen
no
where do microbes live in humans
throughout the GI tract - mostly large intestine
what do GI microbes do in human
- synthesize (aka make) vitamins + other nutrients
- compete w/ pathogens (disease causing bacteria/virus) for space and resources
why do most fresh foods have short shelf life
contamination is impossible to prevent
how does short shelf life affect the food industrry
economic loss cause of food spoilage
some ways food safety is maintained
- tracking disease outbreaks
- monitoring for pathogens
- canada food inspection agency
effects of fermentation of food products by microorganisms
preserve food and give flavour. eg, yogurt, cheese
effects of fermentation by yeast in food products
produce CO2 + alcohol. eg, raising dough, making wine rum etc
In fermentation process, what does glucose produce
- 2 lactic acid
- 2 ethanol + 2 CO2
What does lactic acid produces to in fermentation process
propionic acid + acetic acid + CO2 —- used in cheeses
What food used lactic acid for fermentation
sauerkraut
What food used ethonal for fermentation
alcoholic beverages
What does ethanol produce
acetic acid — used in pickles
what are biofuels
liquid fuels produced from renewable resources like used vegetable oil, animal fat etc
Examples of biofuels
ethanol and methane
What can produce ethanol (biofuel)
yeast! from corn, grasses etc
What produces methane (biofuel)
Archaea, methanogens. through anaerobic metabolism — v imp part of natural gas
what is bioremediation
use of microorganisms to breakdown environmental pollutants
examples of where microorganisms can be used in bioremediation
they can consume spilled oil, solvents, pesticides and other toxic pollutants
how are microorganisms brought into polluted environments
deliberately introduced or nutrients are added to stimulate them
what is the goal of adding microorganisms to polluted environments
accelerate the removal of these pollutants
what happens in industrial microbiology
growth of microorganisms on a massive scale
What is the purpose of massive scale growth of microorganisms
to make large amounts of relatively low-value products
What are some examples of low value products made in industrial microbiology
enzymes, chemicals, antibiotics
what is biotechnology
using genetically engineered microorganisms to synthesize products of high value
examples of products that are high value produced using microorganisms
human proteins, insulin etc
who invented the single lens microscope that could observed bacteria
antoni van leeuwenhoek
who published the book micrographia (a book about microscopic observations)
robert hooke
Where do organisms come from
- develop for “seeds or germs” from air
- spontaneously from non living material aka spontaneous generation
What causes alcohol fermentation
growth of microorganism – not a pure chemical process
bacterial growth in polluted containers can be prevented. How?
Through heating. The bacteria produces lactic acid
Louis pasteur disapproved one the theories of where microorganisms come from, what was that
spontaneous generation
Do living organisms discriminate between iosmers
yes
What did pasteurs experiment develop
effective sterilization procedures in microbiological research, clinical med and food industry
What did edward jenner discover about cowpox
that it could give cross immunity to smallpox
what did pasteur find that prevented diseases in chicken
spoiled culture of cholera. After being exposed to it, chickens could not be infected
What method in vaccination did pasteur find
artificially weaken disease organisms
What bacteria causes anthrax
Bacillus Anthracis
What does anthrax infect
primarily cattle
Who studied anthrax
robert koch
Where was Bacillus anthracis in the animal
in the blood of the animal. Koch wasnt sure if that bacteria caused the disease
what is a pure culture
culture containing a single kind of microorganisms
what are colonies
masses of cells with characteristic shape and color
What can colonies determine
shape, size and nutrient characteristics
how are bacteria species differentiated
different types were considered different species – based off of their colonies
Bacteria responsible for tuberculosis
Mycobacterium tuberculosis
who discovered the bacteria that causes tuberculosis
robert koch
What is used to diagnose tuberculosis
tuberculin skin test
bacteria responsible for cholera
Vibrio cholerae
who developed the enrichment culture technique
Martinus Beijerinck
What is the enrichment culture technique
use of selective culture media and incubation conditions to isolate specific microbes from natural samples
what are chemolithotrophs
group of phylogenetically diverse microbes that can obtain all the energy required for their growth from the oxidation of inorganic compounds such as hydrogen
who described/defined chemolithotrophs
sergei winogradsky
what is genomics
mapping, sequence and analysis of genomes
What fueled many advances in microbiology
genomics
what is a genome
entire set of DNA instructions found in a cell
How can you positively identify pathogens without lab culture
they usually have “signature” genes
How did the signature genes in pathogen benefit
fast and accurate diagnosis + applied to ancient med questions
What caused the black death
bacterium Yersinia pestis
What kind of plague did black death cause
bubonic plague
how was black death transmitted
rodent & flea bites
impact of black death
25 million died - 1/3rd of europe / lasted 4 yrs
