Ch. 4 Functional Anatomy of Prokaryotic and Eukaryotic Cells Flashcards
Prokaryote
comes from the Greek words for prenucleus
Eukaryote
comes from the Greek words for true nucleus
Avg. size of bacterial cells
0.2 to 2.0 micro meters x 2 to 8 micro meter length
Most bacteria are
monomorphic ( single shape)
a few bacteria are
pleomorphic (many shapes)
Bacillus
rod shaped
coccus
spherical shape
Spiral
-Vibrio
-Spirillum
-Spirochete
Star-shaped
Rectangular
Pairs
diplococci, diplobacilli
Clusters
staphylococci
Chains
Streptococci, streptobacilli
groups of four
tetrads
cubelike groups of eight
sarcinae
Scientific name
Bacillus (Bold)
Shape
bacillus
Glycocalyx
- External to the cell wall
- Viscous and gelatinous
- Made of polysaccharide and/or polypeptide
- Two types
– Capsule: neatly organized and firmly attached
– Slime layer: unorganized and loose - Contribute to virulence
– Capsules prevent phagocytosis
– Extracellular polymeric substance helps form biofilms
Flagella
- Filamentous appendages external of the cell
- Propel bacteria
- Made of protein flagellin
Three parts of Flagella
– Filament: outermost region
– Hook: attaches to the filament
– Basal body: consists of rod and pairs of rings;
anchors flagellum to the cell wall and membrane
Taxis
Flagella allow bacteria to move toward or away from stimuli
Flagella rotate
to “run” or “tumble”
Archaella
- Archaeal motility structure
- Made of glycoproteins archaellins
- Anchored to the cell
- Archaella (singular: archlaellum) rotate like flagella
Axial Filaments
- Also called endoflagella
- Found in spirochetes
- Anchored at one end of a cell
- Rotation causes cell to move like a corkscrew