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Chapter One: Microbial Life and Origin, Chapter Two: Microbial Life -- Diversity and Classification, Chapter Three: Observing the Microbial Cell
What is a Microbe?
A living organism that requires a microscope to be seen. A microbe can be single or multiple Cellular and Contain their own genome to reproduce.
What is the known cell size range for microbes?
Millimeters To 0.2 Micrometers. (Viruses can be 10 times smaller)
What is special about cyanobacteria?
The Are photosynthetic meaning that it self-produces energy via Sunlight.
What is another name for the eukaryote, protist?
Protozoa
What is the common name for a large group of microbes like an algae or fungi?
A Lichen
What are some of the Exceptions ot the single definition of a microbe?
Supersized Microbial cells (ex. Thimargarita namibiensis)
Microbial Communities that must stick together to survive (i.e. Biofilms)
Viruses (mimivirus)
What factor is the biggest reason we have not found microbes smaller that 0.2 micrometers yet?
The surface area to volume ration dictates the amount of space inside of the cell that the microbe would have to house the necessary materials for survival, meaning that as the microbe gets smaller the less Fit for survival the microbe becomes.
What are the three domains of life?
Bacteria, Archaea, and Eukarya
What is the difference between Bacteria and Archaea?
Archaea | Bacteria |
Types | |
Methanogens, Thermophiles, and Halophiles | Gram-positive and Gram-negative |
Cell Wall | |
Pseudopeptidoglycan | Lipopolysaccharide/ Peptidoglycan |
Metabolism Activity | |
They perform modified form of glycolysis and citric acid cycle. | They perform glycolysis and citric acid cycle. |
Cell membrane | |
Ether-linked lipids | Ester-linked lipids |
Thriving Habitat | |
They can sustain in extremely harsh environments such as hot springs, marshlands, deep sea vents, and the gut of humans and ruminants. | They are found everywhere, including soil, organic matter, the earth’s crust, water, bodies of animals and plants, radioactive wastes, hot springs etc. |
For centuries Microbes have shaped human civilization, from food and beverage making (Yeast in Beer and Cheese) to Destroying Ancient Monuments. However what have microbes done most?
Infection, microbes have caused more death than any war combined, an example is brucellosis in the spinal column.
What is the good news today about microbes and their constant infection?
The epidemic of microbial infection is still an issue, however due to modern medicine the devastation of infection has drastically decreased.
True or False:
More soliders died of microbial infections than of Wounds in battle.
True; In fact Florence Nightingale in the 1850s first recognized disease in warfare.
Nurse nightingale used what device to show the deaths of soliders due to carious causes?
A Polar Area Chart
When was Robert Hooke Living?
1635-1703
What did Robert Hooke do and when/where did he publish his finding?
He built the first compound microscope, observed mold, and coined the term cell. His findings were published in Micrographia in 1665.
When was Antonie van Leeuwenhoek Living?
1632-1723
What was Leeuwenhoek’s profession and what did he accomplish?
He was a cloth draper and he built a single-lens magnifier, complete with a sample holder and focus adjustment. This allowed him to be the first to observe single-celled microbes, calling them “small Animals”.
What do you call a microscope with one lense?
a Simple Microscope
What do you call a microscope with multiple lenses
A Compound Microscope
What is the name of the theory that living creatures could arise without parents. The primary example was maggots arising from nothing?
Spontaneous Generation
WHy did many people question Sponataneous Generation?
Religon
Who first showed that maggots in decaying meat were the offspring of flies by keeping some meat in a sealed jar and some meat in an open air jar?
Francesco Redi (1660s)
Who first showed that a sealed flask of meath broth sterilized by boiling failed to grow microbes?
Lazzaro Spallanzani (1760s)
Why did Louis Pasteur’s findings debunk the skeptics of the original findings of Redi and Spallanzani?
Since skeptics denied Redi and Spallanzani’s finding due to the Absence of air, Pasteur’s swan flask debunked the nature of this hypothesis by proving that a lack of air was not an Issue.
What is Louis PAsteur in the 1860s discover?
The microbial Basis of Fermentation, proposing Biogenesis
How did Pasteur disprove spontaneous generation?
He devised a “swan-neck” flasks and showed that, after boiling, the contents remain free of microbial growth, despite access to air.
What is the basic definition of Biogenesis?
Life comes from Life
Why did Pasteur’s Swan Flask work?
Since microbes are heavier than air, gravity has an effect on them thus not allowing microbes to climb the swan neck to reach the material inside of the flask.
What is the Germ theory of disease that was first Devised in 1880s?
The idea that many diseases are caused by microbes.
Who determined germ Theory>?
Robert Koch, a German Physcian and founder of the scientific method of microbiology.
Why did it take humans so long to connect microbes with infectious disease?
Not all microbes cause disease
Lack of communication between Scientists.
Koch applied hi mehtod to many letahl diseases dn determined that which were bacteria?
Antrax and the Bubonic Plague
Koch also determined that some were parasitic Protozoa, what is an example of one of his findings?
Malaria
Koch demonstrated a transmission of a disease using anthrax. What is “transmission of a disease” also called?
Chain of Infection
What was needed to Prove a particular bacterium caused a specific disease?
A Pure Culture
What did Angelina and Walther Hesse invent?
A Solid medium using Agar
What did julius Petri Invent?
A Double-dish Container (Petri Dish)
What is the First Step of Koch’s Postulate?
Microbe is always present in diseased host And Absent in Healthy.
What is the Second Step of Koch’s Postulate?
The microbe must be grown in a pure culture, with no other microbes present.
What is the Third Step of Koch’s Postulate?
The Pure microbe should be introduced in a healthy host, causing the individual to become sick.
What is the Fourth Step of Koch’s Postulate?
The new sick host can have the previous microbe isolated from said host.
Why does Koch’s first Postulate not always work?
Microbes are everywhere, there for the immune system can keep infections at bay, meaning that the microbe in question can be found in a healthy host.
Why does Koch’s Second Postulate not always work?
Not all microbes can grow in a medium, infact only about 1% of microbes can. Some microbes require a host such as a virus and theses require a cell culture.
Why does Koch’s Third Postulate not always work?
Similarly to the first Postulate, it is not a Guarantee that the Microbe will Make an individual sick, Because of the Individual’s immune system.
Why are Cancer cells used for a Cell Culture?
Cancer cells do many replications, meaning they can eaasily survive a viral attack.
What makes Archaea and Eukarya more related than Bacteria?
The way that they Transcribe RNA, Translate DNA, and Synthesize Proteins
Whao was Carl Woese
He was a Microbiologist that discovered prokaryotes that lived in hot springs and Produced methane. Analysis of the microbes rRNA revealed it was a distinct organism which he called Archaea.
What is Woese’s discovery do?
Regrouped The five kingdoms of life into three equally distinct groups called Domains: Bacteria, Archaea, and Eukarya
What does the three domain model say about mitochondria?
It was derived from proteobacteria.
What does the three domain model say about Chloroplast?
It was Derived from Cyanobacteria
In the 18th century, small pox infected a large fraction of Europe. In Asia and Africa, the effects of Small Pox was less, why?
Deliberate smallpox inoculation
Who first introduced Smallpox inoculation to Europe?
Introduced from Turkey by Lady Mary Montagu in 1717
Who introduced small pox inoculation to the American Colonies?
Mr. ONnesimus, a slave from West Africa
Who is the Father of Immunology adn how did He get the title?
Edward Jenner (1749-1823) gained the title by deliberately infecting patients with matter from cow Pox lesions, which made individuals also immune to small Pox.
Where does the term vaccination come from?
the practice of Cow pox Inoculation because Latin for Cow is “Vacca”.
What did Louis PAsteur (1822-1895) develop?
The first vaccines based on attenuated (weakened) strains. Some vaccines of bacteria he produced were Fowl Cholera and Rabies.
What is the stimulation of an immune response by deliberate inoculation with an Attenuated pathogen called?
Immunization
What is Ignaz Semmelweis do in 1847?
He ordered doctors to wash their hands with chlorine, and antiseptic agent, which cause the mortality rates of women in childbirth to fall.
What did Joseph Lister do in 1865?
He developed a carbolic acid to treat wounds and clean surgical instruments. His chemical was the first safe chemical for humans but not for microbes.
In the twentieth century, _______ surgery was developed
Aseptic
30 years earlier a French student Discovered something and published his findings. What did Alexander Fleming rediscover?
The ability of Penicillium mold to generate a substance that kills bacteria. (Also known as an Antibiotic)
In 1941, what did Howard Florey and Ernst Chain Purify adn create?
They Purified penicillin, creating the first commercially available antibiotic to save human lives.
What is the problem with Penicillin Today?
Due to over use from its Initial discovery Penicillin has become almost entirely useless due to bacterial Natural Selection for Penicillin Resistance.
What did Sergei Wnnogradsky discover?
That microbes are everywhere, specifically discovering lithotrophs. He did this by building what is known as a Winogradsky column to develop enrichment cultures.
What is a Winogradsky COlumn?
A wetland model ecosystem containing regions of enrichment for microbes of diverse metabolism.
What is a lithotroph?
Organisms that feed on inorganic minerals
What can be found near the top of a Winogradsky column?
Cyano Bacteria and other “Oxygen needing” organisms.
What can be found near the Bottom of a Winogradsky column?
Sulfate-reducing bacteria and other Oxygen Hating Organisms like Archaea.
What strand of rRNA was Carl Woese looking for?
SS-RNA specifically, 16-s RNA (For Bacteria)
What does analysis of 16S rDNA sequences show?
Archaea are classified separately from bacteria.
Which of the following evidences show that mitochondria have evolved by endosymbiosis from early bacteria engulfed by pre-eukaryotes.
Hint: Choose more than one answer. You will lose points for selecting the wrong answer.
Mitochondria are able to grow and divide on their own if placed under a suitable media
Mitochondria have their own ribosomes with same size as bacterial ribosomes
Mitochondria have a double membrane which is similar to gram negative bacterial cell membrane
Mitochondria have their own DNA that resembles bacterial DNA
Mitochondria have their own ribosomes with same size as bacterial ribosomes
Mitochondria have a double membrane which is similar to gram negative bacterial cell membrane
Mitochondria have their own DNA that resembles bacterial DNA
What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains, rather than assigning all prokaryotes to the same kingdom?
Small subunit rRNA gene sequence
Which statement about the domain Archaea is NOT accurate?
Hint: Choose more than one answer. You will lose points for selecting the wrong answer.
No archaea can inhabit solutions that are nearly 30% salt.
Genetic prospecting has revealed the existence of both bacterial and eukaryal genes.
The genomes of archaea are unique, contains no genes that originated within bacteria.
No archaea are adapted to water temperatures above the boiling point.
No archaea can inhabit solutions that are nearly 30% salt.
The genomes of archaea are unique, contains no genes that originated within bacteria.
No archaea are adapted to water temperatures above the boiling point.
Compared to eukaryotes, which of the following statements do you think is TRUE to prokaryotes (that includes both bacteria and archaea).
simpler morphologically, but very diverse and complex metabolically
Why was Carolus Linnaeus (1707-1778) definition of microbes?
He called microbes chaos because so little was known about microbial life and microbes do not fit the classic definition of a species.
What is the classic definition of a species?
a group of organisms that interbreeds
What were the two challenges that faced early taxonomists as they attempted to classify microbes?
Resolution of the light microscope was too low
overcome via advances in microscopy and biochemistry
Microbial species are hard to define
Microbiologists have devised working definitions of microbial species
> ≥95% similarity of DNA Sequence
What did Ernest Haeckel (1860s) determine?
Microbes are neither plant nor animal, naming them the third kind of life called Protista (Monera)
Meaning that one group represented all microbes
What did Herbert Copeland (1966) determine?
That Monera should be divided into two groups
eukaryotic protist (protozoa and algae)
Prokaryotic bacteria
This created 2 groups of microbes and set the prescedent for 4 kingdoms of life.
What did Robert Whittaker (1969) Determine?
Added Fungi as a fifth kingdom of eukaryotic microbes.
Who drastically modified the five-kingdom system by instituting the Endosymbiosis Theory?
Lynn Margulis (1960s)
What is the endosymbiosis theory?
The proposal that Mitochondria evolved from prokaryotic cells that was engulfed by pre-eukaryotes that became animal, plant, protist, and Fungi. Also proposing that chloroplasts evolved from a Prokaryotic cell that was engulfed by a pre-eukaryote that already contained mitochondria Resulting in cells that can photosynthesize life like plants.
Why was endosymbiosis theory highly controversial?
The theory implied that one organism engulfed another organism in order to evolve. Resulting in multiple species being an Ancestry fro another species. This directly contradicted Darwinian evolution which is based on Divergent evolution.
What is the evidence of Endosymbiosis Theory?
Mitochondrial and Chloroplast DNA
circular DNA (found in Bacteria and Archaea)
Lots of Bacterial DNA in Genome
Mitochondrial and Chloroplast Ribosomes
Exactly the same as bacterial ribosomes
Size and Morphology (Shape)
Pretty much the same as bacteria
True or False:
Compared to the amount of phylum in the Eukarya Domain, Bacteria have exponentially more phylum and Archaea have way more as well, just not as many as Bacteria.
True
What is the name of spherical bacteria?
Cocci
What is the name of Rod shaped Bacteria
Bacilli (singular), Bacillus (Plural)
What is the name of Spiral-shaped Bacteria?
Spirochetes; flexible cell wall
Spirilla; rigid cell wall
What arguments support the Classification of Archaea as a third domain of life?
They share characteristics of both bacteria and eukarya. To bacteria they are similar in size and shape. They differ in their 16S-SSrRNA. Sharing similarities with Eukarya by having introns, having eukaryotic homologs for the RNA polymerase & Transcription Factors, being Ribosome resistant ot chlorophenicol, and other chemicals, and having methionine for a translation indicator.
More than ______% of what we know about microbes today was discovered after _____. Including struture & Function of _____ _______ and ___________ the DNA and _____ revolution which discovered ___________ DNA and __________ engineering.
99
1900
cell Membrane
macromolecules
RNA
recombinant
genetic
What two insturments had a huge imapct on the study of microorganisms?
The electron Microscope
the ultracentrifuge
The electron microscope revealed the internal structure of cells. who Developed it?
Ernst Ruska
The ultra centrifuge was developed by Theodor Svedberg. What did it enable us to do?
It enabled the separation of Sub-cellular parts, like DNA, using the density of the parts.
At first Geneticist though that genetic material was a protein, instead of DNA. In 1928 Frederick Griffith discovered that Bacteria would transform and exchange genetic material. Who determined it was DNA?
Oswald Avery and colleagues proved the transforming substance was DNA.
Who determined that DNA was a double helix using x-Ray crystallography?
Rosalind Franklin
Who determined that DNA was made up of complementary bases and had Antiparallel structure. In fact, to show this, they Built the first model.
James Watson, Francis Crick, and Maurice Wilkins
What did Thomas D. Brock do?
He looked at hot springs and found a bacteria called Thermus Aquaticus that was heat Adapted, meaning that the internal proteins and structures could function at higher temperatures than other bacteria.
Why was a heat stable bacteria important?
Bacteria can recombine DNA from unrelated organism and the first DNA work was done in bacteria and bacterialphages. By having a heat stable bacteria the DNA polymerase could be worked with more efficiently by humans.
What is the process to amplify DNA and who developed it?
PCR or Polymerase Chain Reaction
Kary Mullis
How do we use bacteria?
To create and discover antibiotics
Vaccinations
Industrial microbiology
Uses bacteria to clone and produce insulin
Bioremediation
Note 
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