Lecture 1 Flashcards
What groups do microbes include?
Bacteria, fungi, protozoa, microscopic algae, viruses
What are microbes?
Minute, living things too small to see with the unaided eye
What do bacteria in human intestines synthesize?
Some B vitamins for metabolism
Vitamin K for blood clotting
What are some commercial products synthesized by bacteria?
Chemicals such as acetone, organic acids, enzymes, alcohols and drugs
In 1914, Chaim Weizmann, discovered what?
The process by which microbes produce acetone and butanol
What was the production of acetone useful for when world war I started?
Making cordite (gunpowder)
What are some substances that microbes have been manipulated into producing, despite not normally?
Cellulose, digestive aids, drain cleaner, therapeutic substances (insulin)
What does pathogenic mean?
Disease-producing
Who created the bionomical system of nomenclature?
Carolus Linnaeus, in 1735
What are the two names assigned to an organism?
The genus, the specific epithet (species)
Why are bacteria called prokaryotes?
Because their genetic material is not enclosed in a nuclear membrane
What two groups are included in prokaryotes?
Bacteria, archaea
What are the shapes of bacterial cells?
- Bacillus: rodlike
- Coccus: spherical/ovoid
- Spiral: corkscrew or curved
- Star-shape
- Square
In what type of formation can individual bacteria be arranged?
- Chains
- Clusters
- Other groupings
What is the composition of a bacterial cell wall?
Carbohydrate and peptidoglycan (protein complex)
How do bacteria most commonly reproduce?
Binary fission
How do archaea differ from bacteria?
Where present, their cell walls do not contain peptidoglycan
What are the three main groups of archaea?
Methanogens
Extreme halophiles
Extreme thermophiles
What are fungi?
- Eukaryotes
- Single or multicellular
What is the cell wall of fungi composed of?
Chitin
What are unicellular fungi called? How are these different to bacteria (other than being eukaryotes)?
Yeasts, larger than bacteria
What are the most typical fungi called?
Molds
What are visible masses that mold form called?
Mycelia, composed of hyphae
How do fungi reproduce?
Sexual and asexual reproduction
What are protozoa?
Unicellular eukaryotic microbes
How do protozoa move?
Psuedopods, flagella, cilia
How do amoebas move?
Psuedopod
How do protozoa reproduce?
Sexually or asexually
What are algae?
Photosynthetic eukaryotes
What is the cell wall of algae composed of?
Cellulose
What are the two major groups of parasitic worms? What are these collectively called?
Flatworms and roundworms
Collectively called helminths
How many years ago did life first appear on Earth?
~3.8 billion years ago
For how many years was the atmosphere anoxic?
2 billion years
How many years ago did eukaryotic life evolve?
~2 billion years ago
What name is given to the process by which microorganisms degrade/detoxify pollutants such as oil or mercury?
Bioremediation
Name a bacteria that is fatal to most insects by harmless to humans and plants?
Bacillus thuringiensis
Name 2 food additives produced by microorganisms.
Monosodium glutamate, citric acid
Bacteria are ______. They are found in all types of ecological niches.
Ubiquitous
What are microbial communities?
Dynamic, interacting populations of microbes found in nature
What is a microbial habitat?
The environment in which a microbial population lives.
What is an ecosystem?
The microbial communities, as well as the physical and chemical constituents in their environment
Define microbial ecology.
The study of microbes in their natural environment
What are the two things microbes in communities can do?
- Interact with each other
- Interact with the chemical and physical environment
What are the two ways microbes in communities can interact with each other?
- Cooperation
- Competition
What is an infection that can be caused by biofilms?
Endocarditis- Inflammation of the heart
Approximately how many microbes are present in or on the human body?
10^13
What are two benefits of the normal microbiota present in or on humans?
- Prevent growth of pathogens
- Produce growth factors such as folic acid and vitamin K
