Chapter 1 Lecture Flashcards
What organisms are too small to be seen with the unaided eye, and how do they play a role in our life.
Microorganisms, microbes, and germs.
Contrary to public belief, most are beneficial to us
Define pathogenic in regards to microbes
Pathogenic means disease-causing
Only a select few cause disease
What the job of microbes that are involved in the Elemental cycle?
Decompose waste
What do producers do and what do consumers do?
Microbes are producers in the ecosystem and this happened via photosynthesis
What are some of the roles of microbes in our lives?
Few are pathogenic
They decompose wastes
Some are producers in the ecosystem by photosynthesis
Some produce chemicals such as ethanol and acetone
Some ferment foods such as vinegar, cheese, bread, wine, beer
Some are used for genetic engineering: meaning they produce products that we need
E.g. Cellulase and treatments like insulin
What a few benefits of microbes?
Knowledge of microorganisms allows humans to
-prevent food spoilage
-prevent disease occurrence
Led to aseptic techniques, which prevents contamination in medicine and in micro labs
Who is responsible for establishing the system of scientific nomenclature?
Linnaeus
How are organisms named?
They have two name:
The genus which is capitalized and the specific epithet (species name), which is lower case
What are two other ways a scientific name could be written?
Italicizes or underlined
Could be descriptive or honor a scientist
What did Theodor Escherich discover? Where is this found?
Escherichia coli, E.coli
The bacterium’s habitat- the large intestine, or colon
Describe Staphylococcus aureus?
Clustered (staphylo-). Spherical (cocci) cells
Gold-colored (aureus) colonies
Where is Staphylococcus aureus found
S.aureus is found in the nose
What are the types of microorganisms?
Bacteria Archaea Fungi Protozoa Algae Viruses Multicellular animal parasites
Describe bacteria?
Prokaryotic or Eukaryotic
Type of cell wall
How they replicate
What is their energy source
Prokaryotic (meaning prenucleus)
Peptidoglycan cell wall
Binary fission
They use organic chemicals, inorganic chemicals, or photosynthesis
Describe Archaea?
Also Prokaryotic
LACK peptidoglycan
Like to live in extreme environments
E.g. Methanogens, extreme halophiles - high salt, extreme thermophiles - high temp
Are Fungi prokaryotic or Eukaryotic
Eukaryotic
Describe Fungi?
Have Chitin cell walls
Use organic chemicals for energy
What are a few examples of Fungi and explain?
Describe yeasts
Molds and mushrooms, are multicellular, consisting of masses of mycelia, which are composed of filaments of hyphae
Yeasts are unicellular
Are Protozoa Eukaryotic or Prokaryotic?
Protozoa are Eukaryotic
Describe Protozoa?
Give and example
Eukaryotes
unicellular
Absorb or ingest organic chemicals
May be motile via pseudopods, cilia, or flagella
E.g. Amoeba
Describe algae
Eukaryotes
Their cell was are made of cellulose
Use photosynthesis for energy
Produce molecular oxygen and organic compounds
What are viruses
Acellular
Consist of DNA or RNA core
Core is surrounded by a protein coat (capsid)
Coat may be enclose in a lipid envelope
How do viruses replicate?
What are they referred to as?
Only replicate in a living host cell
Referred to as intracellular parasites
Describe multicellular Animal Parasites
What are some examples?
Eukaryotes
Multicellular animals
Parasitic flatworms, roundworms which are called (helminths)
Microscopic stages in life cycle
What is the classification of organisms
By Three Domains
1- Bacteria
2- Archaea
3- Eukarya
How is the domain Eukarya broken down?
Kingdoms:
- protists
- fungi
- plants
- animals
What was considered the first life on earth?
Ancestors of bacteria were the first life on Earth
When was the first microbe observed?
1673
Who reported that living things were composed of little boxes, or cells?
Robert Hooke in 1665
Who stated that cells arise from preexisting cells?
Rudolf Virchow 1858
What is the cell theory?
All living things are composed of cells and come from preexisting cells
Who was the first to describe live microorganisms and what did he call them?
How did he see them
Anton van Leeuwenhoek was the first to describe live microorganisms and he called them animalcules.
He saw them under a microscope he made
What is spontaneous generation?
The hypothesis that living organisms arise from no living matter; a vital force forms life. Meaning God made life
What is biogenesis:
The hypotheses that the living organisms arise only from preexisting life
Who was the first to attempt to find evidence of either spontaneous generation or biogenesis?
Francesco Redi in 1668
What was Francesco Reid’s experiment?
He wanted to disprove spontaneous generation
Three jars covered with fine net. = no maggots
Three open jars = maggots appeared
Jars with plug = no maggots
This is spontaneous generation
What did set out to disprove the cell theory with boiled broth? What was the out come?
John Needham in 1745
Boiled broth then transferred to sealed flask and the results were microbial growth
He thought this could only be spontaneous generation because he didn’t take into account the microbes in the air due to he had no idea
Who also boiled nutrient solutions in flasks to support biogenesis and said that heat destroyed the vital force?
Lazzaro Spallanzani in 1765
Placed nutrient broth in flask then heated it and sealed it. No transferring! His results were no microbial growth
He thought it was biogenesis
Who was the first to demonstrate that microorganisms are present in the air? What did he prove?
Louis Pasteur in 1861
His S-shaped flask kept microbes out but let air in. Microbes couldn’t move upward in the tube to affect the contents in the flask
When is the Golden Age of Microbiology? What was the start of this age?
1857-1914
Louis Pasteur’s work is where it began and later Koch
During this period what discoveries were made?
The relationship between microbes and disease, immunity, and antimicrobial drugs
Chemical activation of microorganisms
Improved microscopy techniques
Vaccines were developed
Surgical techniques to prevent infections
Who showed that microbes are responsible for fermentation?
What is fermentation used for?
Pasteur showed that microbes are responsible for fermentation, which is the conversion of sugar to alcohol to make beer and wine) no O2
What else is microbial growth responsible for during the discovery of fermentation and pasteurization
Microbial growth is responsible for food spoilage
Bacteria that use alcohol and produce acetic acid spoil wine (by souring and spoilage) by turning it to vinegar (acetic acid) in the presence of O2.
How did Pasteur show that spoilage bacteria could be killed?
It could be killed by heat that was not hot enough to evaporate the alcohol in wine
What is the term for the application of heat for a short period of time to food to prevent spoilage?
Pasteurization
What is the definition of Ubiquitous?
What did Pasteur show?
Microorganisms are present in no living matters: air, liquid, and solid, this is referred to as Ubiquitous.
Microbial life can be destroyed by heat
We can block the entry of microbes to nutrient environment (Aseptic technique)
What is the germ theory of disease?
Referred to the idea that microorganisms cause disease
Who showed that a silkworm disease was caused by a fungus
Agostino Bassi 1835
Who believed that another silkworm disease was caused by a protozoan
Louis Pasteur 1865
Who advocated that hand washing to prevent transmission of puerperal (childbed fever) fever from one patient to another?
Ignaz Semmelweis 1840
Who used a chemical disinfectant (phenol to clean fomites) to prevent surgical wound infections?
What did this prove?
Joseph Lister
It further proved Pasteur’s point that microbes cause infections
Who provided the most important evidence that a specific microbe causes a specific disease?
Robert Koch proved that bacillus anthracite caused anthrax, he gave all of his experimental steps called “Koch’s Postulates”
What are Koch’s postulates?
- Microorganism should be found in blood of infected animal
- Then culture bacteria on nutrients
- Then inject culture (bacteria) into a healthy animal
- When the animal dies, the same bacteria should be isolated (found) in their blood.
Who was the first person to come up with vaccination and what was the vaccine?
Edward Jenner in 1796 inoculate a person with cowpox virus (mild form), this then protected them from small pox
How did Jenner continue to inoculate individuals for small pox?
He took scrapings from cowpox blisters and inoculated healthy individuals
Where was vaccination derived from?
What is this protection called?
From vacca, for cow
Protection is called immunity
How did Pasteur figure out how the process of vaccination worked?
What was the outcome of his studies?
He studied cholera in chickens
He found that bacteria lost the ability to cause disease over time (virulence)
If grown for a long time in the lab the bacteria became (avirulence)
Define Chemotherapy?
Treatment with chemical is Chemotherapy
Chemotherapeutic agents consisted of what hand what were they used to treat?
Used to treat infections disease can be synthetic drugs or antibiotics
Define antibiotics
Chemicals that are produced by bacteria and fungi that inhibit or kill other microbes
Who created the first synthetic drugs?
What are some examples of the first synthetic drugs?
Paul Erlich
Speculated about a “magic bullet” that could destroy a pathogen without harming the host
1910 he developed synthetic arsenic drug “Salvarsan” to treat syphilis
Quinine from tree bark was long used to treat malaria
1930’s the sulfonamides were synthesized
Who discovered the first antibiotic and what was it?
Alexander Fleming discovered the first antibiotic
Penicillium fungus made the antibiotic penicillin
What does penicillin kill and what was done with this discovery?
Staphylococcus aureus
1940, penicillin was tested clinically and then mass produced
What are the modern developments in Microbiology?
Define them
Bacteriology- the study of bacteria
Mycology- study of fungi
Virology- study of viruses
Parasitology- study of Protozoa and parasitic worms
Define immunology?
What its being used to study immunology?
Immunology is the study of immunity
Vaccines and interferons are being investigated to prevent and cure viral diseases
What was Rebecca Lancefield’s contribution to immunology?
1933- The use of immunology to identify some bacteria according to serotypes
Define microbial genetics?
The study of how microbes inherit traits
Define molecular biology?
The study of how DNA (gene) directs protein synthesis
Define Genomics?
The study of an organism’s genes, has provided new tools for classifying microorganisms
Define recombinant DNA
Who was responsible for developing this?
DNA made from two different sources
Paul Berg inserted animal DNA into bacterial DNA (cloning), and the bacteria produced an animal protein
In 1941 who showed that genes encode a cell’s enzymes?
George Beadle and Edward Tatum
Who showed that DNA was the hereditary material?
Oswald Avery, Colin MacLeod, and Maclyn McCarty
In 1961 who discovered the role of mRNA in protein synthesis?
Francois Jacob and Jacques Monod
The Elemental cycle is what?
Bacteria recycle carbon, nutrients, sulfur, and phosphorus that can be used by plants and animals
This plays a major role in supporting life
Who studied the phenomenon of the elemental cycle? What is an example?
Winogradsky
E.g. Nitrogen fixations by Rhizopus: converts N2 gas into a form that can be used by other organisms
Example is sewage treatment plants use this method to clean sewage
What is bioremediation?
Bacteria degrade organic matter in sewage
What is another example of what bacteria can degrade?
Bacterial degrade or detoxify pollutants such as oil and mercury
Ex. Pseudomonas
How have we moved past using chemical pesticides and what is the benefits?
(Biological Insecticides) Microbes that are pathogenic to insects are alternatives to chemical pesticides in preventing damage to agricultural crops and disease transmission
Define Bacillus thuringiensis?
Infections are fatal in many insects but harmless to other animals, including humans and to plants.
What are some of the uses of Biotechnology?
The use of microbes to produce foods and chemicals like milk, curd is produced to make cheese etc…
What technique is used for biotechnology, that enables bacteria and fungi to produce a variety of proteins including vaccines and enzymes
Recombinant DNA technology
What are some example of what recombinant DNA technology is used for?
Missing or defective genes in human cells can be replaced in gene therapy
Genetically modified bacteria are used to protect crops from insects and from freezing
What was the original term for microbes and what has this term been replaced with?
Flora
Microbiota
Define normal Microbiota?
Microbes that are normally present in and on the human body are normal Microbiota
What are the benefits of normal Microbiota?
prevent growth of pathogens
Produce growth factors such as folic acid and vitamin K
We are resistant to these microbes though!
What is resistance?
The ability of the body to ward off disease
What are some resistance factors?
Include skin, Stomach acid, and antimicrobial chemicals
What microbes attach to solid surfaces and grow into masses?
Where do they grow?
Biofilms
they grow on rocks, pipes, teeth, and medical implants
What is infectious diseases?
When a pathogen over comes the host’s resistance, disease results
What is Emerging infectious diseases (EID’s)?
New diseases and diseases that are increasing in incidence
What is Avian influenza A (bird Flu)
Influenza A virus (H5N1)
Primarily in waterfowl and poultry
2003 it killed millions of poultry and 23 people
how does a bird pass H5N1
Some birds are carriers
Through saliva, and feces
What is a carrier?
Carriers means = infected but do not show the symptoms of disease
What is MRSA and how has it progressed and evolved?
Methicillin-resistant Staphylococcus aureus
1950 - a resistance to penicillin developed
1980 - Methicillin resistance developed
1990 - MRSA became resistant to vancomycin
What is VISA and VRSA?
Vancomycin-intermediate-resistant Staphylococcus aureus
Vancomycin-resistant S.aureus
Explain West Nile Encephalitis (WNE)
What is it caused by and what is its history
Caused by West Nile Virus
First diagnosed in the West Nile region of Uganda in 1937
Appeared in New York in 1999
Virus carried by birds and transmitted to horses and humans by mosquitoes (via vector)
In 2004, 200 people were infected in the U.S.
Mad cow disease is what disease?
What is it caused by?
Bovine Spongiform Encephalopathy (BSE)
Caused by a prion (infectious protein)
-also causes Creutzfeldt-Jakob diseases (CJD
This was first seen in 1982 and is the leading cause of diarrhea worldwide?
Escherichia coli O157:H7
This causes fever, hemorrhaging, and blood clotting
Ebola Hemorrhagic Fever
Ebola virus
First identified near Ebola River, in the Congo
Outbreaks every few years
This was first reported in 1976 and is responsible for 30% of diarrheal illness in developing countries
Cryptosporidiosis
Cryptosporidium Protozoa
In the US its transmitted via water
This disease was first identified in 1981 and its a disease that is primarily sexually transmitted
(AIDS) Acquired immunodeficiency syndrome
Caused by HIV
HIV/AIDS in the U.S. 30% are female, and 75% are African American
This is caused by Streptococcus and was reported in 1995
Flesh-Eating Bacteria
