Topic I Introduction to Microbiology Flashcards
what is microbiology?
the study of the biology of microorganisms.
microbiology includes the study of what things?
Which are acellular and which are cellular?
- Viroids, Prions, Virusoids and Viruses – acellular entities
- Prokaryotes (bacteria) - cellular
- Eukaryotes - cellular
name some eukaryotes (4)
Protozoa
Many algae
Some fungi
Helminthe (worm) Larvae
*look at slide 4 flow chart
slide 5
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describe Domain Bacteria (5)
- Usually single-celled
- Majority have cell wall with peptidoglycan
- Lack a membrane-bound nucleus
- Ubiquitous and some live in extreme environments
- Cyanobacteria and some others produce amounts of significant oxygen
**pictures on slide 8
describe Domain Archaea (3)
Lack peptidoglycan in cell walls
Have unique cell membrane lipids
Many live in extreme environments
what distinguishes Domain Archaea from Domain Bacteria
Domain Archaea is Distinguished from Bacteria by unique rRNA sequences
what 2 things make up Domain Eukarya - Eukaryotic?
describe both
Protists: generally larger than Bacteria and Archaea
Fungi: chemoheterotroph absorbers
what are 4 examples of Protists? say something about each
Algae – photosynthetic
Protozoa – chemoheterotrophs
Slime molds – chemeoheterotrophs with two life cycle stages
Water molds – devastating disease in plants
what are 2 examples of Fungi? is each unicellular or multicellular?
Yeast – unicellular
Mold - multicellular
describe viruses (3)
- Smallest of all microbes
- Requires host cell to replicate
- Cause range of diseases, some cancers
what are Viroids and Virusoids?
Infectious agents composed of RNA that are acellular
what are Prions?
infectious proteins that are acellular
Microbiology studies the following aspects of microorganisms: (6)
Biochemistry Morphology Physiology Genetics Ecology Evolution
what are the 2 aspects of microbiology?
- ) Understanding basic life processes (basic science)
- Microbes are excellent models for understanding cellular processes in unicellular and multicellular organisms - ) Applying that knowledge to the benefit of humans (applied science)
- Microbes play important roles in medicine, agriculture, and industry
why are microorganisms important? (12)
- Oldest form of life (3.9- 3.8 b.y.a)
- Microbes found almost everywhere but most live in oceans and soil
- Largest mass of living material on Earth (⅓– ½ of world’s biomass); Global estimate of 5x10^30 cells
- Carry out major processes for biogeochemical cycles (i.e., nitrogen, carbon)
- Other life forms require microbes to survive
- Cause many human and animal disease
- Cause most plant disease
- Cause 99.99 % of all decomposition
- Responsible for the deterioration of organic materials
- Many useful products are made by microorganisms
- Bioremediation
- Food/Beverages
what are the 9 characteristics of life?
1) Composed of one or more cells
2) Highly organized
3) Responds to environmental changes (stimuli)
4) Grows and develops
5) Adapts to changing environments (evolves)
6) Requires and uses energy
7) Undergoes metabolism
8) Regulation and homeostasis
9) Reproduction
slides 18-21
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who was the first person to observe and describe microorganisms accurately? How did he do this?
- Antony van Leeuwenhoek (1632-1723)
- used simple microscope
What is spontaneous generation?
Who discredited this theory and how did he do it?
- Spontaneous generation: living organisms can develop from nonliving or decomposing matter
- Francesco Redi (1626-1697) discredited this by showing maggots on decaying meat came from fly eggs
Who is Louis Pasteur (1822-1895) and what did he do that was important?
-Helped disprove spontaneous generation His experiments: -placed nutrient solution in flasks -created flasks with long, curved necks -boiled the solutions -left flasks exposed to air Results: no growth of microorganisms
**slides 25-29
What other contributions we made by Pasteur?
- demonstrated that alcohol fermentations and other fermentations were the result of microbial activity
- developed the process of pasteurization to preserve wine during storage
What contributions were made by Pasteur and his coworkers?
developed vaccines for chicken cholera, anthrax, and rabies
What is the Germ Theory?
belief that certain diseases were caused by microorganisms
Why was the Germ Theory not immediately obvious?
Infectious disease believed to be due to supernatural forces, other factors
**Establishing connection depended on development of techniques for studying microbes
multiple scientists did experiments that provided evidence for the Relationship between Microorganisms and Disease (4)
- ) Agostini Bassi (1773-1856)
- showed that a disease of silkworms was caused by a fungus - ) M. J. Berkeley (ca. 1845)
- demonstrated that the great Potato Blight of Ireland was caused by a water mold - ) Heinrich de Bary (1853)
- showed that smut and rust fungi caused cereal crop diseases - ) Louis Pasteur (1822-1895)
- demonstrated microorganisms carried out fermentations; showed that the pébrine disease of silkworms was caused by a protozoan
Slide 33
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too much info in 1 slide
What are the four things for Koch’s Postulates?
- The microorganism must be present in every case of the disease but absent from healthy individuals
- The suspected microorganism must be isolated and grown in a pure culture
- The same disease must result when the isolated microorganism is inoculated into a healthy host
- The same microorganism must be isolated again from the diseased host
- look at slide 36 for an example
What are the 2 limitations to Koch’s Postulates?
- ) Some organisms cannot be grown in pure culture (some cellular and all viruses)
- ) Using humans in completing the postulates is unethical
The 20th/21st century, microbiology developed in two distinct directions. What are those 2 directions?
applied and basic
what are the major subdisciplines of applied microbiology?
-Medical microbiology and immunology
(Have roots in Koch’s work)
-Agricultural microbiology and industrial microbiology
Many aspects of __________ depend on microbial activities.
What are the positive and the negative impacts?
Agriculture;
Positive impacts:
-nitrogen-fixing bacteria
-cellulose-degrading microbes in the rumen
-regeneration of nutrients in soil and water
Negative impacts:
-diseases in plants and animals
*slide 41
what are the major subdisciplines of applied microbiology?
agriculture?
- ) Aquatic microbiology and marine microbiology
- Developed from advances in soil microbiology - ) Microbial ecology
- Emerged in 1960s–70s
what are the basic science subdisciplines in microbiology? describe them/what the study is (5)
- ) Microbial systematics
- The science of grouping and classifying microorganisms - ) Microbial physiology
- Study of the nutrients that microbes require for metabolism and growth and the products that they generate - ) Microbial biochemistry
- Study of microbial enzymes and chemical reactions - ) Bacterial genetics
- Study of heredity and variation in bacteria - ) Virology
- Study of viruses
What is biotechnology?
- Manipulation of cellular genomes
- DNA from one organism can be inserted into a bacterium and the proteins encoded by that DNA harvested
