Lecture Quiz 1 Flashcards
What are Microorganisms?
Organisms that are too small to be seen with the unaided eye.
What do Microorganisms do?
breakdown organic waste, producers in the ecosystem by photosynthesis, produce industrial chemicals such as ethanol and acetone, produce fermented foods such as vinegar, cheese, and bread, manufacturing (cellulase) and treatment (insulin) a few are pathogenic.
What do Microorganisms allow humans to do?
prevent food spoilage ( refrigerator, use of chemicals), prevent disease occurrence, led to aseptic techniques to prevent contamination in medicine and in microbiology laboratories.
Who established the system of scientific nomenclature?
Linnaeus
What two names each organism have?
genus and specific epithet.
How to identify scientific names?
italicized or underlined. scientific names may be abbreviated with the first letter of the genus and the specific epithet
What do Bacteria have?
Prokaryotes (no nucleus), cell walls, Binary fission, use organic chemicals inorganic chemicals, or photosynthesis for energy.
What do Viruses have?
Acellular, Consist DNA or RNA core, core is surrounded by protein coat, coat may be enclosed in a lipid envelope, viruses are replicated only when they are in a living host cell. Not a living organisms.
Classification of Microorganisms
THREE DOMAINS: Bacteria and Archaea (both are prokaryote) Eukarya under this (protists, fungi, plants, Animals) they all have nuclues
Who was first life on Earth?
bacteria
When was microbes first observed?
1673
What is cell theory?
all living things are composed of cells, cells come from preexisting cells, cell is the smallest unit of life
What is spontaneous generation?
living organisms arise from nonliving matter, a vital force forms life.
What is biogenesis?
living organism arise from preexisting life
Example: 1668: Francisco Redi filled six jars with decaying meat
Conditions: three jars covered with fine net. Results: no maggots
Condition: three open jars. Results: maggot appeared.
Biogenesis occurred
Example:1745: John Needham put boiled nutrient broth into covered flasks.
Conditions:Nutrient broth heated then placed in sealed flask
Results: Microbial growth
Spontaneous generation because flask was not sanitized
Example: 1765: Lazzaro Spallanzani boiled nutrient solutions in Flasks.
Conditions: Nutrient broth placed in flask, heated, then sealed.
Result: No microbial
biogenesis but did not convince everyone
Example: 1861: Louis Pasteur demonstrated that microorganisms are present in the air.
Conditions: Nutrient broth placed in flask, heated, not sealed - flask remains upright
Results: No microbial growth
Conditions: Nutrient broth placed in flask, heated, not sealed- flask tilted
Results: Microbial growth
Biogenesis
When was the Golden Age of Microbiology?
1857-1914
Pasteur’s work, discoveries include the relationship between microbes and disease, immunity, and antimicrobial drugs.
What is Pasteur show?
microbes are responsible for fermentation, fermentation is the conversion of sugar to alcohol to make beer and wine, microbial growth is also responsible for spoilage of food, demonstrated that these spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine
What is pasteurization?
the application of a high heat for a short time
Why did Joseph Lister use chemical disinfectant?
to prevent surgical wound infections.
What did Robert Koch prove?
bacterium causes anthrax and provided the experimental steps, to prove that specific microbe causes a specific disease
The use of Vaccination
1769: Edward Jenner inoculated a person with cowpox virus. The person was then protected from smallpox.
What can Bacteria do for human welfare?
recycle carbon, nutrients, sulfur, and phosphorus that can be used by plants and animals.
What can Bacteria do in Bioremediation?
degrade organic matter in sewage and degrade or detoxify pollutants such as oils and mercury.
What are Biological insecticides?
Microbes that are pathogenic to insects are alternatives to chemical pesticides in preventing insect damage to agricultural crops and disease transmission.
What is Biotechnology?
the use of microbes to produce foods and chemicals, is centuries old.
What is Genetic engineering?
is a new technique for biotechnology. Through genetic engineering, bacteria and fungi can produce a variety of proteins including vaccines and enzymes.
What are microbes on human bodies?
Microbiota, normal microbiota prevent growth of pathogens and produce vitamins.
What are Infectious Diseases?
a pathogen overcomes that host’s resistance, disease results. Emerging infectious diseases (EID): new diseases and diseases increasing in incidence. (HIV, Ebola, West Nile, SARS, Avian Influenza)
Explain the difference between abiogenesis (spontaneous generation) and biogenesis?
living organisms arise from nonliving matter, a vital force forms life and living organism arise from preexisting life.
Describes Louis Pasteur’s swan-necked flask experiment and explain what it proves?
Conditions: Nutrient broth placed in flask, heated, not sealed - flask remains upright
Results: No microbial growth
Conditions: Nutrient broth placed in flask, heated, not sealed- flask tilted
Results: Microbial growth
Proves: Biogenesis
microorganisms are present in the air
Give 5 ways in which microorganisms benefit humankind?
Fermentation, recycle carbon, nutrients, sulfur, and phosphorus that can be used by plants and animals, Microbial ecology, degrade organic matter in sewage and degrade or detoxify pollutants such as oils and mercury,to prevent surgical wound infections, Vaccinations
Give 2 ways in which microorganisms harm humankind?
infectious disease, pathogen overcomes the hosts resistance
Describe 3 Pasteurs accomplishments?
microbes are responsible for fermentation, fermentation is the conversion of sugar to alcohol to make beer and wine, microbial growth is also responsible for spoilage of food
What is microscopy?
a simple microscope that has only one lens
What does shorter wavelengths provide?
greater resolution
What is resolution?
ability of the lenses to distinguish two points
What is the refractive index?
the light-bending the ability of a medium
What is the Brightfield illumination?
dark objects are visible against a bright background
What is the Darkfield illumination?
light objects are visible against a dark background
What is the Phase-Contrast Microscopy?
accentuates DIFFRACTION of the light that passes through a specimen
What is Fluorenscence Microscopy?
- uses UV light
- very sensitive
- tool to identify unknown organisms or proteins
What is Confocal Microscopy?
- uses fluorochromes and a laser light
- laser illuminates each plane in a specimen to produce a 3-D image
What is Electron Microscopy?
- uses electrons instead of light
- shorter wavelength of electrons gives greater resolution
What is Transmission Electron Microscopy (TEM)
- ultrathin sections of specimens
- electrons goes through in slices (must be stained with heavy metal)
What is Scanning Electron Microscopy (SEM)?
- scans surface of the object
What is Scanning-Probe Microscopy?
- scanning tunneling microscopy uses a metal probe to scan a specimen
- resolution 1/100
What is a Smear?
- a thin film of a solution of microbes on a slide
- usually fixed to attach the microbes to the slide and to kill the microbes