Ch 1-3 Microbio Flashcards
Describe the environments where microbes live on Earth
-Microbes thrive in diverse environments (i.e antartica, underground, air, toxic waste, food, drink, and inside living organisms
-They adapt to extreme conditions, making them both harmful and beneficial
Describe a microbe in terms of size and characteristics
-Size: range from 0.2 µm to a mm
-Features:
Require a microscope to be seen; have a genome that encodes proteins for energy, reproduction, and environmental response
Define a genome
The complete set of genetic material in an organism, essential for life functions
Distinguish between prokaryotes and eukaryotes
-Prokaryotes: No nucleus, smaller, include bacteria and archaea
-Eukaryotes: have a nucleus and organelles, larger in size
Distinguish among bacteria, archaea, and microscopic eukaryotes, and viruses
-Bacteria: single celled, no nucleus, found everywhere
-Archaea: similar to bacteria but thrive in extreme conditions
-Microscopic eukaryotes: fungi, algae, protozoa
-Viruses: non-living, require a host to replicate
Describe at least 2 ways that microbes are involved in human food production
-Yeasts: for bread, wine, and beer
-Bacteria for yogurt and cheese
Name at least 2 other ways that microbes have affected human history
-Positive: antibiotics, fermentation
-Negative: Diseases like smallpox, black death, tuberculosis
Describe how microbes are connected with historic wars/battles
Battlefield deaths often caused by infectious diseases (e.g., before antibiotics)
Place on a timeline key events in microbiological history
-Observation of contagious diseases ~1550
-Microscopic observation: 1660s (1st microscopist) 1676 (AVL-first to see bacteria)
-Spontaneous generation disproven: 1688 (maggots), 1864 (bacteria)
-Sterilization: 1765
-Antiseptics: 1798
-Pure culture: 1882
-Koch’s postulates/gram staining: 1884
-Antibiotics discovered: 1929
-Antibiotics in use: 1944 (penicillin)
Describe Robert Hooke’s microscopic observations and contribution to biology
-Built first compound microscope
-Coined the terms cells with said microscope
Describe Antonie Van Leeuwenhoek’s observations of bacteria
-First to observe bacteria using a single-lens magnifier
Describe the debate around spontaneous generation in the 1700s and how it was disproven by Francisco Redi and Lazzaro Spallanzani
SG debate: living creatures can arise spontaneously, without parents
-Redi: maggots come from flies, not meat
-Spallanzani: sealed boiled broth –> showed no microbial growth
Describe how Louis Pasteur finally laid to rest the theory of spontaneous generation
Swan-neck flask experiment confirmed microbes don’t arise spontaneously (even with access to oxygen)
Describe how John Tyndall discovered spores and killed them
Discovered bacterial spores (someetimes boiled growth medium still grows microbes) and methods to kill them with repeated cycles of boiling and resting
Describe the germ theory of disease and contrast it with the four humors theory
-Germ theory: microbes cause infectious diseases
-Four humors: blood, yellow bile, black bile, and phlegm determine a person’s temperament (a deficit or imbalance in one causes sickness)
Describe methods to obtain a pure culture of a microbe, including the use of solid media
-Pure culture: use of solid media (agar plates) to isolate microbes
-Could also dilute sample into tubes until a tube only gets 0 or 1 bacteria in it
Describe Koch’s postulates defining the causative agent of a disease
Criteria for establishing that an infectious microbe is responsible for a
disease:
1. Microbe found in all cases of disease but not in healthy individuals
2. Microbe can be isolated from diseased host and grown in pure
culture
3. Introduction of the microbe into a healthy host will result in the
same disease
4. Microbe can be re-isolated from the newly diseased host, and
shows the same characteristics in culture
Describe the basic theory behind immunization and why it works
-How it works: exposure to a weakened pathogen triggers immune response, protecting against future infections
-Edward Jenner: developed the first smallpox vaccine
Describe the use of antiseptics and aseptic environments as ways to prevent microbial infections
Diseases can easily be transferred. Washing hands, etc., helps prevent transfer of infections
Define an antibiotic and name the first highly successful antibiotic
-Antibiotic: molecules that kill/inhibit bacteria without harming hosts
-Penicillin
Describe a Winogradsky column and its relationship to microbial ecosystems
A whole microbial ecosystem is involved in cycling nutrients in the environment. This column demonstrates microbial ecosystems
Describe microbial nitrogen fixation and its importance
Conversion of nitrogen gas to ammonia for plants
Describe extremophiles and why they can be useful to humans
-Microbes living in extreme conditions (e.g., thermal vents)
-Importance: biotechnology and industrial applications
Define a microbiome and distinguish it from microbiota
-Microbiome: all microbes in an environment
-Microbiota: microbes specifically in or on the human body
Describe how bacteria were at the forefront of DNA revolution in biology
Bacteria helped uncover DNA structure, gene expression, and genetic engineering
Name several fields in microbiology
Experimental, medical, food, industrial, environmental, bioremediation, immunology, and more
Define resolution
smallest distance by which two objects can be separated and still be distinguished
Define mm, micrometer, and nanometer, and the factors among them
-Millimeter (mm): 1mm = 1k micrometers
-Micrometer (µm): 1 µm = 1k nanometers
-Nanometers (nm): extremely small; used for viruses and molecular structures
