Chapter 1 Flashcards
What did Leeuwenhoek’s discover, and what impact did his skills and his discovery have on science?
- Leeuwenhoek discovered microorganisims
- He was a very skilled observed and made magnifying glasses
- His discovery forever changed the scientific world and Leeuwenhoek was elected to the royal society because of it.
What 6 groups of organisms are studied in microbiology?
- bacteria
- viruses
- protozoans
- fungi
- algae
- helminths
What are the basic differences between prokaryotic and eukaryotic cells?
- Prokaryotic cells lack nuclei
- Prokaryotic cells are smaller
- Prokaryotic cells have no cytoskeleton
What is spontaneous generation?
the supposed production of living organisms from nonliving matter
What expirements supported spontaneous generation?
- Needham’s Experiments
- Leeuwenhoek’s discovery of microbes
What expirements did not support spontaneous generation?
- Spallanzani’s Experiments
- Pasteur’s Experiments
Describe the scientific method
The method by which questions are answered through observations of the outcomes of carefully controlled experiments, instead of by conjecture or according to the opinions of any authority figure.
What steps are involved with the scientific method?
What did Louis Pasteur discover and what where his contributions to microbiology?
- Pasteur discovers the chemical process behind fermentation
- Pasteur then develops a method to reduce theamount of wine that spoils due to contamination.
- Pasteur also created the pasteurization process
What did Robert Koch discover?
Robert Koch discovers the pathogen that causes anthrax, Bacillus anthracis.
What are the steps of Koch’s postulates?
- The suspected agent must be found in every case of the disease and absent from healthy hosts.
- The agent must be isolated and grown outside the host.
- Must cause the same disease when introduced to a healthy experimental host.
- Must reisolate the same agent in the diseased experimental host.
What are Microorganisms/microbes?
All organisms that are too small to be seen without a microscope
What is a Theory?
a supposition or a system of ideas intended to explain something
What is fermentation?
The chemical breakdown of a substance by bacteria, yeasts, or other microorganisms
ex: sugar to alcohol
What is metabolism?
the sum of all chemical reactions within an organism
What is the germ theory of disease?
Microorganisms are responsible for diseases
What is a pathogen?
microorganisms that cause specific disease
What is a gram stain?
A stain used to identify bacteria
What is recombinant DNA technology?
The manipulationg of genes in microbes, plants, and animals for practical applications
What is gene therapy?
A process that involves inserting a missing gene or repairing a defective one in human cells
What is meant by gram-positive?
This means that the bacterial cell walls have a relatively thick layer of peptidoglycan that also contains unique chemicals calledteichoic acids.
What is meant by gram-negative?
This means that the cell walls have only a thin layer of peptidoglycan, but outside this layer is an asymmetric bilayer membrane.
What are the contrubiton of Ignaz Semmelweiss?
Hungarian obstetrician
Pushed aseptic technique specifically hand washing.
What are the contrubiton of Joseph Lister?
Used aseptic techniques and cleanliness to decrase mortality
Lister as a surgeon used carbolic acid, or phenol, in the operating room
What are the contrubiton of Florence Nightingale?
Used aseptic techniques and cleanliness to decrease mortality rates.
Worked as a English nurse in Crimean War kept clean wards, and removed potential tiems of infection. Statistically showed poor food and unclean condition caused deaths
What are the contrubition of John Snow?
1854 – mapped an outbreak of cholera in London and showed that it centered around a public water supply.
The advent of epidemiology – the occurrence , distribution and spread of disease in humans.
Snow highlighted the need for adequate sewage treatment and a clean water supply
What are the contrubition of Edward Jenner?
English Physician developed the first vaccine for smallpox from cowpox.
Begins the field of immunology
What are the contrubition of Paul Ehrlich?
Begins the search for chemicals that destroy pathogen while harmless to humans
Alexander Fleming is the first to discover penicilin
Leads to chemotherapy
Why aren’t Koch’s postulates always useful in proving the cause of a given disease?
Koch’s postulates are not useful in determining the cause of diseases that are not infections. Some diseases only occur under specific conditions, so the microbes may be present in asymptomatic persons, and Koch’s first postulate is not met.
Albert Kluyver said “From elephant to…bacterium – it is all the same!” What did he mean?
Kluyver was referring to the metabolism/biochemistry that is common to all cellular life on the planet regardless of the number of cells per organism or size. The statement can be extended to shared cellular structures as well.
Algae do not cause disease to humans because?
Algae have simple nutritional requirements (carbon dioxide, water, light, a few salts), which are easily obtained from the environment; therefore, they do not need to obtain nutrients from other living things.
How might the debate over spontaneous generation have been different if Buchner had conducted his experiments in 1857 instead of 1897.
Buchner’s experiments demonstrated that intact living cells were not required for fermentation of sugars. Had the experiments been done in the 1850’s, prior to Pasteur’s experiments on spontaneous generation, one argument for spontaneous generation (the appearance of yeast cells in fermenting sugar solutions) would have been weakened. Spallanzani’s results might have been more widely accepted as demonstrating that spontaneous generation does not occur. When scientists accepted that animals do not arise from spontaneous generation, they might have been less likely to exempt microorganisms.
The ability of farmers around the world to produce crops such as corn, wheat, and rice is often limited by the lack of nitrogen-based fertilizer. How might scientists use Beijerinck’s discovery to increase world supplies of grain?
Beijerinck’s discovery that some bacteria can convert nitrogen gas to nitrogen compounds is important to the cultivation of these grains. It may be possible to (1) introduce into the soil bacteria capable of converting N2 to organic forms of nitrogen, (2) create soil conditions which promote the growth of such bacteria, and/or (3) genetically modify crop plants with bacterial genes to convert nitrogen gas for themselves.
