Chapter 1: Microbial Life Flashcards
Are all microbes microscopic?
No. EX: Thiomargaria namibiensis (largest bacteria, .1-.3 mm)
Types of nonliving microbes
- viruses
- prions (found in neurons in the brain, causes misfolded proteins
- viroids
What are two diseases caused by prions in humans?
- vCJD
- bovine spongiform encephalopathy, AKA mad cow disease
What does prokaryote mean?
What are some characteristics?
“Before kernel (nucleus)”
- cytosol as opposed to cytoplasm
- No membrane bound organelles
- no nucleus but they have nucleoid and ribosomes
What does eukaryotes mean?
What are some characteristics?
“ True nucleus”
- larger, 10-100 microns in diameter
- unicellular or multicellular
- cytoplasm
- membrane bound organelles
- Secretes mucollagenous substance
- numerous bacteria which are attached to each other as well as the surface
- The form where water is
Biofilms
Ex: plaque, biofilm in Pipes in spas
Groups of individuals cells
Colonies
Where do microbes live?
- ubiquitous (beneficial and pathogenic)
- May be free living
- May form communities (colonies, biofilms)
Three types of acellular microbes
-viruses,
Composed of proteins and nucleic acid
-viroids, composed of RNA (plant diseases)
-prions, composed of proteins)
Hansen’s disease, mycobacterium (acid fast + bacterium) AKA…
Leprosy
Yersinia pestis
AKA Bubonic plague or black death
Transmission rodent fleas are handling an infected animal
1/3 to 1/4 European died
Sedlec Ossuary
Small Roman catholic chapel,
Decorated with skulls from the plague 1300s
First nurse to recognize the impact of disease on soldiers, first to use medical statistics to demonstrate mortality
Florence Nightingale
- built first compound microscope (two lenses of magnification)
- first to view view cork plant cells and mold
- published micrographia
- coined the term “cell”
Robert Hooke
Was the first to apply the word “cell” to biological objects. He coined that term because plant cells, which are walled, remind him of cells in a honeycomb
Robert Hooke
- A cloth Draper
- built single lens magnifiers, complete with sample holders and focus adjustment
- first to observe single celled microbes, called them “animacules” (tiny animals, mostly unicellular)
Antoni van Leeuwenhoek
- for elements required (fire, Earth, air, water)
- Aristotle thought living organisms could develop from nonliving materials with the elements
Spontaneous generation a.k.a. Abiogenesis
Who contributed to disapproving spontaneous generation?
- Francisco Redi (experiments with meat and maggots
- Lazzaro Spallanzaoni (boiled beef broth, failed to grow any microbes)
- Louis Pasteur (devised “swan-neck” flaks), show that after boiling the contents remain free of microbial growth despite access to air
- ** prove the theory of biogenesis
What other scientific contributions did Louis Pasteur make?
- discovered many of basic principles of microbiology
- pasteurization (does not completely sanitize just reduces microbes) he did this with wine to avoid spoilage
- discovered that alcohol fermentation is caused by yeast
- immunology (chickens became immune to bacterial disease if injected attenuated pathogen, produce vaccines against many organisms, first rabies vaccine)
Developed Fowel Cholera and rabies vaccine
Louis Pasteur
Mycobacterium leprae
Leprosy, acid fast + bacterium
Yersinia petit
Bubonic plague or Black Death
Transmitted by rodent fleas
1/3 to 1/4 of Europeans died
Who proved the germ theory of disease?
Propose that specific diseases are caused by specific pathogen‘s
Pasteur
Who studied the etiology of disease
- anthrax
- _______ postulates
Robert Koch
Koch’s postulates
Who helped pave the way for Robert Koch?
Angelina and Walther Hesse (solid medium using agar)
Julius Petri (Petri dishes)
- German physician
- developed principles and methods crucial to microbial investigation
- supplied his methods to the study of several lethal diseases around the world
Robert koch
Are an ordered side of criteria for establishing a causative link between an infectious agent and a disease
Koch’s postulates
What are Koch’s postulates?
- Suspected microbe is always present in diseased host (absent in healthy host)
- Suspected microbe is grown in pure culture outside host (no other microbes present in culture)
- Cultured microbe is introduced into a healthy host. Individuals become sick with the same disease as original host.
- Same microbial suspect is re-isolated from sick individual
Exceptions to Koch’s postulates
- not all microbes can be grown in vitro
- more than one micro produces the same disease
- disease is caused by combinations of pathogen‘s
- One microbe that causes multiple diseases
- strictly human diseases with no animal model
- diseases in which pathogen‘s have been ignored
Who coined the word vaccination? He infected patients with cowpox
He was widely ridiculed
Edward Jenner
Who made significant contributions towards infection control?
He kept getting pushed out of hospitals for his “radical ideas”
-observed decrease death rate in midwives ward versus Dr. ward
* linked puerperal fever to “cadaver particles”
-Preliminary aseptic technique‘s
Ignaz Semmelweis
- Credit for first aseptic technique‘s (Advanced idea of antisepsis)
- carbolic acid (phenol) solution
Considered father of anti-septic surgery
Joseph Lister
Who made significant contributions to chemotherapy?
- Alexander Fleming
- linked bacterial growth inhibition by penicillin
- discovered lysozymes (enzyme found in tears and nasal mucus) by chance
- Ernst Chain and Howard Florey
- developed penicillin (purified penicillin to be used)
Dmitri Ivanovsky
Discover the cause of tobacco mosaic virus through infectious leaves
Filterable pathogens‘s
Martinus Beijerinck
Was the first to call tobacco mosaic a virus
Wendell Stanley
Extracted the Tobacco mosaic virus and pure crystals (viruses made of proteins in an RNA)
Percentage of microbes that can be studied
Less than 1%
- Russian scientist he was among the first to study microbes and natural habitats
- discovered lithotrophs
- developed enrichment cultures
- built the ________ column,
Sergei Winogradsky
The Winogradsky column
A model of a wetland ecosystem containing regions of enrichment for microbes utilizing diverse metabolism‘s
Pathway by which a chemical substance moves through biotic compartments of the earth called the biosphere and the abiotic compartments (lithosphere, atmosphere, and hydrosphere)
-reservoirs(can remove for long periods of time)
Biogeochemical cycles
-diverse group of organisms using an inorganic substrate usually of mineral origin to obtain reducing equivalents for use in biosynthesis
Lithotrophs
- Oxidize hydrogen sulfide as an energy source, forming intracellular sulfur droplets
- inhabit marine or freshwater environments
Who first discovered this?
Beggiatoa (lithotroph)
Winogradsky
Process by which organisms derive energy from a number of different in organic compounds and obtain carbon in the form of CO2
Who first discovered?
Chemoautotrophy
Winogradsky
A microbe living symbiotically inside of a larger organism
Endosymbiont
Ex: rhizobia, remnant animals and insects, human intestinal bacteria
2 kingdom system
3 kingdom system
4 kingdom system
5 kingdom system
2- Linnaeus
3- Ernst Haeckel
4-Herbert Copland
5- Robert Whittaker
Who proposed that organelles evolve through Endosymbiosis?
Lynn Margulis
She modified the five kingdom system dramatically
What evidence supports the Endosymbiotic theory?
- mitochondria and chloroplasts are similar in size in morphology to bacterial prokaryotes cells
- mitochondria and chloroplasts have their own DNA in their own ribosomes
- have their own cell membrane
- both replicate independently of the cell by binary fission
- phylogenetic studies demonstrate that mitochondria and chloroplasts are related to bacteria
Who divided prokaryote into eubacteria and archeobacteria?
Carl Woese
What are the three domains?
Bacteria, Archaea, and eukarya
Who discovered bacterial transformation? We’re bacteria could transfer genetic info to nearby cells
Fredrick Griffith
Who discovered DNA is the genetic material
Oswald Avery
Who discovered DNA structure?
Rosalind Franklin, James Watson, and Francis Crick
RNA world hypothesis
Suggests RNA was the first self replicating genetic reserve
Describes a pre-cellular stage in which RNA was capable of storing, copying, and expressing genetic information as well as catalyzing other metabolic reactions
Early cells may have been liposomes “ pseudo cells” containing RNA
A piece of RNA that can replicate itself
Like an RNA-based enzyme
Ribozymes
