chapter 1 - introduction to microbiology Flashcards
What is a microorganism?
an organism too small to be seen by the unaided eye
What is a microbial community?
two or more populations of cells that coexist and interact in a habitat
What is microbiology?
the study of dominant form of life on Earth and the effects that microbes have on living things.
What is a colony?
macroscopically visible population of cells growing on solid medium arising from a single cell.
What are the elements of a microbial structure?
1- have permeability barrier: cytoplasmic membrane
2- cytoplasms
3- ribosomes (responsible for protein synthesis)
4- cell walls
5- prokaryotes: no nucleus or organelles
What do the genomes of bacteria look like?
closed circular chromosomes
What are plasmids?
typically contain genes that are not essential but confer some special property.
contain 1 or more small circles of DNA distinct from chromosomes.
What is transcription?
process by which information encoded DNA sequences is copied into RNA molecule.
What is translation?
process where information in an RNA molecule is used by ribosomes to synthesize a protein.
What is motility?
allows cells to relocate in response to environmental conditions.
What is differentiation?
results in the formation of modified cells specialized for growth, dispersal or survival.
What are the different common morphologies of prokaryotic cells?
- coccus (spherical)
- rod or bacillus (cylindrical)
- spirillum (spiral, rigid)
- vibrio (comma shape)
- spirochette (spiral but not spirillum, flexible)
- filamentous (long, thing)
What are characteristics of bacteria?
i. prokaryotic
ii. mostly unicellular
iii. at least 80 bacterial phyla
What are characteristics of archaea?
i. prokaryotic
ii. extreme environments
iii. no disease causing in animals or humans.
What are characteristics of eukarya?
i. originated during cambrian explosion
ii. first eukaryotes were unicellular
What are viruses?
i. not alive
ii. parasitic
iii. identified based on structureWh
What does anoxic means?
oxygen free
What is microbial ecology?
ways microorganisms affect animals, plants and global ecosystems
What is a pathogen?
a disease-causing microorganism
What are gut microbiomes
microbial community present in animal gastrointestinal tract
What are the impacts of microorganisms on human society?
- agents of disease
- food and agriculture
- valuable human products, energy generation, environmental clean-up
What are examples of industrial microbiology?
- wastewater treatment
- bioremediation
- biotechnology
- biofilms can foul pipes
Why is Robert Hooke known?
the first to describe microbes by illustrating the fruiting bodies of moulds.
Why is Antoni van Leeuwenhoek known?
he had a light microscope with a lens to magnify the image, being the first to describe bacteria.
What are the different types of microscopes?
i. light microscopes
- bright-field
- phase-contrast
- fluorescence
ii. confocal scanning laser microscopy
iii. electron microscopy
What are the two major biological questions?
- does spontaneous generation occur?
- What is the nature of infectious diseases?
What is the aseptic technique?
collection of practices that allow preparation and maintenance of sterile media and solutions
What are pure cultures?
cells from only a single type of microorganisms
What are enrichment culture tehniques?
isolate microbes having particular metabolic characteristics from nature
Why was Louis Pasteur known for?
discovered that fermentation of alcohol and organic acid was mediated by microorganisms.
What conclusions did Louis Pasteur come up with?
- heat killed microorganisms
- microorganisms were responsible for fermentation
- different microbes performed different fermentation processes
