Topic 1 Flashcards
Robert Hooke
microscope, first known depictions of microorganisms, drawings of fruit molds
Antoni Von Leeuwenhoek
first person to see bacteria, father of microbiology :)
What did Leeuwenhoek call bacteria?
Hint: its so cute
wee animalcules
Where did Antoni say microbes came from?
Hint: very stupid… not for 1500 I guess
spontaneous generation
Louis Pasteur smort guy (5 things)
- disproved spontaneous generation
- sterilization important for food
- fermentation
- vaccine development
- germ theory of disease
Germ theory of disease
whether microbes cause disease or not
Koch’s Postulates (4 steps)
- Suspected pathogen must be in all cases of diseased and absent from healthy
- suspected pathogen grown in pure culture
- cells from pure culture must cause disease
- pathogen must be reisolated and show same results
Koch’s postulates implications (2)
- show microbes are not just associated with disease, they cause it
- scientific rigour
Koch’s postulates limitations (2)
- some disease causing pathogen cannot be cultured
- disease causing pathogens can be present in healthy people and only cause disease in some
Robert Koch (4)
TBh hes a big deal (get it?)
Choler-a me surprised…
- methods and principles led to isolation on bacterial cultures
- proved cause of bacterial disease
- postulates are a current cornerstone of infectious disease
- discovered cause of tuberculosis and cholera
Bacteria
primary emphasis of mcb
Extremophiles fall into…
Archea
Eukaryotic examples
algae, mold, plasmodium spp (cause of malaria)
Viruses
genetic elements, only multiply in living cell, HIJACK other cells, NOT CELLS
LUCA
last universal common ancestor
LUCA feature
DNA rep,transcrip,transla, cell division, ATP energy intermediate, lipid bilayer, anaerobic metabolism, limited number of genes,
Chemotroph
derive energy from breaking chemical bonds
Phototroph
absorbs light, transforming into chemical energy
Chemoorganotrophs
break organic molecules
chemolithotrophs
inorganic chemicals breakdown
Devoid of oxygen
anoxic
Bacteria that produce oxygen O2 as waste product
cyanobacteria
Oxygen is a (4)
- great e- acceptor
- gave rise to aerobic organisms
- efficient energy production
- gave rise to complexity
Ozone layer
protects against UV, make planet surface more habitable
When did eukaryotes emerge?
archea like bacteria engulfed an aerobic respiring bacterium = phylum Alphaproteobacteria
Endosymbiont
organism that lives inside another organism in a symbiotic relationship
examples of endosymbionts
mitochondria, chloroplasts
Basis for chloroplast
cyanobacterium
plants emerged in… (first or second event)
second event when photosynthetic bacterium engulfed
Evidence of symbiotic theory
mito and chloro have:
- own genomes, ribosomes and tRNA
- bacterial machinery
- DNA rep/trn/trp similar to archea than bacteria
- related to their precursors (proteabacteria and cyanobacteria
earth is a ……..
hint: there are ~1 x 10^30 of these
microbial planet
Microbes are…
cool sounding word
Ubiquitous - prevalent on every habitat on planet
Microbes lives in ______ and ______ microbial communities
complex and competitive
Competition drives ____ and ____
evolution and diversity
Fun Fact! Our bodies have roughly the same number of microbial and human cells.
Keep going we got this!!
Microbes (like humans) come in many different….
shapes and sizes
Rise of what threatens our existence and could cause a possible apocalyptic event
antibiotic resistance
we use microbes everywhere such as…
industry, biotechnology, food!
Taxonomy
science of classifying and naming organisms
Phylogeny
study of evolutionary relationships between different organisms
Did King Philip Come Over For Great Soup or
Dumb Kids Prefer Cheese Over Green Spinach
domain, kingdom, phylum, class, order, family, genus, species
Carl Linnaeus
system for classification
Genus species
in italics, genus capitalized
Scientific names come from….(3)
Characteristics, scientists, physical property/appearance
Subspecies
finer classification after species
Biovar or biotype
grouping by physiological or biochemical difference within species
Serovar or serotype
grouping based on surface antigens
Strain
specific isolate of genetic variant or subtype
Why taxonomy?
Hint: think of having millions of species without names
a way to bring order to chaos, communicate effectively, and make predictions on cell characteristics
Phylogenic tree
a way to show predicted evolutionary relationships
which way does time go in a phylogenetic tree?
left (root) to right (modern lineages)
branch length shows….
amount of time between nodes
node
most recent ancestor
true/ false Do DNA sequences change over time?
true! most common form of change is mutations
How can we determine how closely organisms are related?
Hint: literally the building block of life
compare DNA sequences that are conserved
more differences in DNA = more evolutionary distance
What DNA sequences should you look for?
highly conserved genes with highly conserved function that has accumulated mutations SLOWLY over time
Ribosomal RNA (___) is encoded by ___
rRNA, rDNA
SSU
small subunit of ribosome
Variable regions useful for…
identifying relationships
regions of rRNA useful for PCR
conserved regions
Woese tree of life (3)
Woe so cool!
- universal tree based on RNA nucleotide sequence similarity
- genealogy of all life on earth
- established the 3 domains Bacteria, Eukarya, Archea
what rDNA is used to identify/classify bacteria
16S
How do you get 16S rDNA (3 steps)
- isolate genomic DNA
- use PCR primers that bind to highly conserved regions of 16S rDNA
- PCR amplify and sequence 16S rDNA
Using a sequences to build phylogenetic trees
- make a tree to align sequences
- distance matrix calculated from number of sequence differences
- tree constructed by addition of nodes
Compare sequences of multiple conserved genes!!
Phylogenetic tree limitations
- they are predictions ( we try but we don’t know for sure!)
- horizontal gene transfer can greatly confuse things
- DNA can undergo homologous recombination
