Microbiology Chapter 1 Flashcards
List several ways in which microbes affect our lives.
10 microorganisms for every human cell, and these microbes contribute to digestion, produce vitamin K, promote development of the immune system, and detoxify harmful chemicals. And, of course, microbes are essential to making many foods we enjoy, such as bread, cheese, and wine.
Distinguish a genus from a specific epithet
The generic name is the genus to which the species belongs, and the specific epithet refers to the species within that genus.
Describe some of the destructive and at least four beneficial actions or uses of microbes
Destructive: Food spoilage and sickness
Beneficial: Decompose organic waste, Digestion, food production, sewage treatments
Differentiate the major characteristics of each group of microorganisms. (bacteria)
bacteria -
- unicellular (single-celled)
- prokaryotes (no nucleus, pre-nucleus)
- several shapes (bacillus - rod like, coccus - spherical, spiral - corkscrew)
- several formations: forms in pairs, chains, clusters
- enclosed in cell walls made of peptidoglycan (carbohydrate:protein complex)
- reproduce by binary fission - division into 2 equal cells
Differentiate the major characteristics of each group of microorganisms. (archaea)
archaea -
- prokaryotic BUT lack peptidoglycan
- live in extreme environments
1) methanogens - produce methane as respiration waste product (marshes, swamps)
2) extreme halophiles - (halo = salt, philic = loving) great salt lake and dead sea
3) extreme thermophiles - (heat), hot sulfurus water, yellowstone national park
Differentiate the major characteristics of each group of microorganisms. (fungi)
fungi (or fungus) -
- eukaryotes (have nucleus)
- chitin cell walls
- two forms: unicellular (yeasts) and multicellular (molds, mushrooms)
- absorb organic materials from environment for nourishment (soil, water, animal, plant)
- sexual (spores) OR asexual (budding) reproduction
1) molds - masses of mycelia composed of filaments (hyphae) that branch and intertwine
Differentiate the major characteristics of each group of microorganisms. (protozoa)
protozoa (protozoan) -
- unicellular eukaryotes
- categorized by motility
- free entities or parasites (nutrients from living hosts)
- absorb or ingest organic chemicals in environment
- sexual/asexual reproduction
motility forms =
1) pseudopods - “false feet” - extensions of cytoplasm
2) cilia - numerous short appendages
3) flagella - long appendage
4) non-motile
Differentiate the major characteristics of each group of microorganisms. (algae)
algae (alga) -
- photosynthetic eukaryotes
- cellulose containing cell walls
- use photosynthesis for energy (need light, water, co2)
- produce O2 used by animals
Differentiate the major characteristics of each group of microorganisms. (viruses)
viruses -
- acellular
- virus particle contains a core that houses either DNA or RNA
- core may be enclosed in a lipid envelope
- viruses need to use cellular machinery to replicate
- inactive outside of host
What are the three domains of life
- Bacteria (pepridoglycan cell wall)
- Achae ( lack peptidoglycan)
- Eukarya
- protists
- fungi
- plants
- animals
Explain the importance of observations made by Hooke and van Leeuwenhoek.
- Robert Hooke observed that cork was composed of “little boxes”; he introduced the term cell (1665).
- Hooke’s observations laid the groundwork for development of the cell theory, the concept that all living things are composed of cells.
- Anton van Leeuwenhoek, using a simple microscope, was the first to observe microorganisms (1673).
Compare spontaneous generation and biogenesis.
- Until the mid-1880s, many people believed in spontaneous generation, the idea that living organisms could arise from nonliving matter.
- Francesco Redi demonstrated that maggots appear on decaying meat only when flies are able to lay eggs on the meat (1668).
- John Needham claimed that microorganisms could arise spontaneously from heated nutrient broth (1745).
- Lazzaro Spallanzani repeated Needham’s experiments and suggested that Needham’s results were due to microorganisms in the air entering his broth (1765).
- Rudolf Virchow introduced the concept of biogenesis: living cells can arise only from preexisting cells (1858).
- Louis Pasteur demonstrated that microorganisms are in the air everywhere and offered proof of biogenesis (1861).
- Pasteur’s discoveries led to the development of aseptic techniques used in laboratory and medical procedures to prevent contamination by microorganisms.
Explain how Pasteur’s work influenced Lister and Koch
- Joseph Lister introduced the use of a disinfectant to clean surgical wounds in order to control infections in humans (1860s).
- Robert Koch proved that microorganisms cause disease. He used a sequence of procedures, now called Koch’s postulates (1876), that are used today to prove that a particular microorganism causes a particular disease.
Summarize in your own words the germ theory of disease.
It states that microorganisms known as pathogens or “germs” can cause disease. These small organisms, too small to be seen without magnification, invade humans, other animals, and other living hosts.
Identify the importance of Koch’s postulates
discovers bacillus anthrasis
prove that specific mocrobes casue specific disease
1. The causative agent must be isolated in every case of the disease.
- The causative agent must be cultured outside the host.
- When injected into a healthy, susceptible host, the host must get the disease.
- The same etiologic agent must be cultured from the once healthy host when it becomes sick.
Identify the importance of Jenner’s work.
- In a vaccination, immunity (resistance to a particular disease) is conferred by inoculation with a vaccine.
- In 1798, Edward Jenner demonstrated that inoculation with cowpox material provides humans with immunity to smallpox.
- About 1880, Pasteur discovered that avirulent bacteria could be used as a vaccine for fowl cholera; he coined the word vaccine.
- Modern vaccines are prepared from living avirulent microorganisms or killed pathogens, from isolated components of pathogens, and by recombinant DNA techniques.
Identify the contributions to microbiology made by Ehrlich and Fleming
- Paul Ehrlich introduced an arsenic-containing chemical called salvarsan to treat syphilis (1910).
- Alexander Fleming observed that the Penicillium fungus inhibited the growth of a bacterial culture. He named the active ingredient penicillin (1928).
- Penicillin has been used clinically as an antibiotic since the 1940s.
Bacteriology
Bacteriology is the study of bacteria
Mycology
Study of Fungi
Parasitology
Study of parasites
Immunology
Study of immunity
Virology
Study of Viruses