4 Flashcards
What is motility?
The ability of an organism to move independently.
What are fimbriae or pili?
Fine, hairlike appendages that are thinner and usually shorter than flagella.
What is the primary function of fimbriae?
Attach cells to solid surfaces, e.g., rocks in streams.
What is the role of Type IV pili?
Aid in motility and 2 gene transfer modes: transformation and conjugation.
How do some bacterial viruses initiate infection?
By attaching to sex pili.
What are flagella?
Threadlike locomotor appendages extending outward from the plasma membrane and cell wall.
What are the functions of flagella?
Motility, attachment to surfaces, and as a virulence factor in some bacteria.
Define virulence factor.
Ability to contribute to the causation of disease.
What is a monotrichous flagellar distribution?
One flagellum at the cell’s end (a polar flagellum).
Describe amphitrichous flagellar distribution.
Two polar flagella, one at each end.
What is lophotrichous flagellar distribution?
A cluster of flagella at one or both ends.
What does peritrichous flagellar distribution mean?
Flagella spread evenly over the entire surface of cells.
What are the three parts of flagella?
- Filament
- Basal Body
- Hook
What is the filament of a flagellum composed of?
The protein flagellin.
What is the function of the basal body in a flagellum?
It is embedded in the cell envelope and is the most complex part of the flagellum.
What is the role of the hook in a flagellum?
Links the filament to the basal body and acts as a flexible coupling.
Name the types of flagellar movement.
- Swimming
- Swarming
- Corkscrew movement of spirochetes
- Twitching motility
- Gliding motility
What is chemotaxis?
Movement toward chemical attractants and away from repellants.
What is endospore formation?
A dormant response to nutrient depletion in certain Gram Positive bacteria.
What conditions can endospores withstand?
Greater exposure to heat, UV radiation, gamma radiation, chemical disinfectants, and desiccation.
Name some dangerous pathogens that form endospores.
- Bacillus anthracis
- Clostridium tetani
- Clostridium perfringens
- Clostridiodes difficile
What is the structure of an endospore?
A core with normal cell structures such as ribosomes and a nucleoid, but low water content.
What are the three stages of endospore formation (sporulation)?
- Activation
- Germination
- Outgrowth
What causes activation in the endospore formation process?
Brief heating and other environmental treatments.
