intro to microbiology 9/5 Flashcards
What are the main categories of organisms studied in microbiology?
- Viroids, Prions, Virusoids and Viruses – acellular entities
- Prokaryotes (bacteria) - cellular
- Eukaryotes - cellular
- Protozoa
- Many algae
- Some fungi
- Helminthe (worm) Larvae
What are the three domains of cellular microorganisms?
- bacteria (true bacteria) - prokaryote
- archaea - prokaryotes
- eukaraya (eukaryotes)
What are characteristics of the domain bacteria?
- Usually single-celled
- Majority have cell wall with peptidoglycan
- Lack a membrane-bound nucleus
- Ubiquitous and some live in extreme environments
What domain does this describe?
- Usually single-celled
- Majority have cell wall with peptidoglycan
- Lack a membrane-bound nucleus
- Ubiquitous and some live in extreme environments
What are characteristics of the domain bacteria?
What are characteristics of domain archaea?
- Distinguished from Bacteria by unique rRNA sequences
- Lack peptidoglycan in cell walls
- Have unique cell membrane lipids
- Many live in extreme environments
What microorganisms are part of domain eukarya?
•Protists – generally larger than Bacteria and Archaea
–Algae – photolithoautotrophs (photosynthetic)
–Protozoa – chemoorganoheterotrophs
–Slime molds – chemoorganoheterotrophs with two life cycle stages
–Water molds – cheomorganoheterotrophs
–Fungi – chemoorganoheterotroph absorbers
- Yeast – unicellular
- Mold - multicellular
What are the different kinds of acellular infectious agents?
- viruses
- viroids and virusoids
- prions
What are characteristics of viruses?
- smallest of all microbes
- requires host cell to replicate
- cause range of diseases and some cancers
What are viroids and virusoids and what are they made up of?
infectious agents composed of RNA; viroids = plant diseases; virusoids = animal diseases
What are prions?
infectious proteins
Why are microorganisms important?
- oldest form of life
- found almost everywhere (most live in oceans and soil)
- largest mass of living material on earth
- carry out major processes for biogeochemical cycles such as nitrogen and carbon cycle
- other life forms require microbes to survive
- cause many human and animal disease and most plant disease
- cause 99.9% of decomposition - prokaryotic or fungal
- responsible for deterioration of organic materials
- many useful products made by microorganisms
- bioremeditation - cleaning environment
- food/beverages - bread, yogurt
What is an observation about infectious disease and death in the US?
Infectious disease is no longer a major cause of death as it was in the 1900s.
- smallest of all microbes
- requires host cell to replicate
- cause range of diseases and some cancers
What are characteristics of viruses?
infectious agents composed of RNA; viroids = plant diseases; virusoids = animal diseases
What are viroids and virusoids and what are they made up of?
infectious proteins
What are prions?
Who was Antony van Leeuwenhock?
- first person to observe and describe microorganisms accurately
- used simple microscope
- 1680s
What is spontaneous generation and who discredited it first?
- living organisms can develop from nonliving or decomposing matter
- francesco redi by showing maggots on decaying meat came from fly eggs
Who is louis pasteur and what did he do?
- helped disprove spontaneous generation
- his experiment involved placeing nutrient solutions in a flask with long curved necks and he boiled the solution and no microorganisms grew; when exposed to air liquid went bad
- demonstrated that alcohol fermentations and other fermentations were the result of microbial activity
- developed the process of pasteurization to preserve wine during storage
- helped disprove spontaneous generation
- his experiment involved placeing nutrient solutions in a flask with long curved necks and he boiled the solution and no microorganisms grew; when exposed to air liquid went bad
- demonstrated that alcohol fermentations and other fermentations were the result of microbial activity
- developed the process of pasteurization to preserve wine during storage
Who is louis pasteur and what did he do?
What did Pasteur and his coworkers develop?
vaccines for chicken cholera, anthrax, and rabies
vaccines for chicken cholera, anthrax, and rabies
What did Pasteur and his coworkers develop?
What is the germ theory?
- belief that certain diseases were caused by microorganisms
- Was not immediately obvious
- Infectious disease believed to be due to supernatural forces, other factors
- Establishing cause-effect connection depended on development of techniques for studying microbes
Who was robert koch?
- established the relationship between Bacillus anthracis and anthrax (~ 1880) and Mycobacterium tuberculosis and tuberculosis
- developed many techniques such as
- agar, petri dish, nutrient broth and nutrient agar, methods for isolating microorganisms
- kochs postulates still used to establish the link between a particular microorganism and a particular disease
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
