Ch 4: Functional Anatomy of Prokaryotic and Eukaryotic Cells Flashcards
How wide is a typical prokaryote?
0.2 - 2 μm
How long is a typical prokaryote?
2 - 8 μm
What is the diameter of a typical Eukaryotic cell?
10-100 μm
Bacillus = ____
Rod-shaped
Coccus = ____
Spherical
Vibrio = _____
Single twist
Spirillum = _____
Thicker spiral, rigid with proper flagella
Spirochete = _____
Thinner spiral with endoflagella (axial filaments)
Stella = ____
Star-shaped
Diplo = _____
Pairs
Staphylo = ____
Grapelike cluster
Strepto = _____
Chains/twisted
What is a glycocalyx? Examples?
General term for a viscous polymer composed of polysaccharides, polypeptides, or both on the cell surface
Ex: capsule & slime layer
What are the differences between a capsule and a slime layer?
Capsule: organized and firmly attached to the cell
Slime layer: unorganized, diffuse, and easily removed
What are some of the functions of a glycocalyx?
- DAttachment to the environment and each other (biofilms)
- Contribute to virulence (capsules mainly)
- Increased resistance to drying and inhibition of nutrient loss
How can capsules contribute to virulence?
Prevent phagocytosis
Facilitate attachment
What capsulated bacteria are resistant to phagocytosis?
- Streptococcus pneumonia*
- Klebsiella pneumonia*
- Bacillus anthracis*
Where does K. pneumonia typically attach itself?
Respiratory tract
Where does Streptococcus mutans typically attach itself?
Teeth
Where does Vibrio cholera typically attach itself?
Small intestine
Label the following flagella types:
Lophotrichous, Amphitrichous, Pertrichous, Monotricous, Atrichous, Cephalotrichous
True or false. Archae flagella are evolutionarily and structurally different from bacterial and eukaryotic flagella.
True
What direction do flagella rotate to move forward?
Counterclockwise
What direction do flagella rotate to tumble?
Clockwise
Taxis- refers to?
Bacterial movement toward or away from a stimulus
Treponema pallidum is a spirohete that causes _____
Syphilis
Borriella burgdorferi is a spirochete responsible for causing _____
Lyme disease
Where are endoflagella located?
Between the cell wall and outer membrane
How do endoflagella function?
Anchored at one pole of the cell and wrapped around
Filament bundles rotate to produce movement of the outer sheath to propel the cell forward in a corkscrew motion
What are the similarities between fimbriae and pili?
Hairlike appendages that are both
- shorter, straighter, and thinner than flagella
- Comprised of pilin arranged helically around a central core
- Present in most gram-negative bacteria
Where do fimbriae typically occur?
At the poles or evenly distributed
What is the role of fimbriae?
Allow bacteria to adhere to each other and to surfaces
How are pili different from fimbriae?
Pili are longer
THere are only one or two pili per cell
What are the functions of pili? (2)
- Bring two cells together to allow for conjugation (sex pili)
- Surface motility (twitching)
In what bacteria are you most likely to observe twitching motility?
- Pseudomonas aeruginosa*
- Neisseria gonorrhoeae*
Some E. coli strains
What is gliding motility?
The ability of certain rod-shaped bacteria to translocate on surfaces without aid of external appendages such as flagella, cilia, or pili
Thought to involve microtubules, but still not well understood