BACTERIAL CELL: STRUCTURES & FUNCTIONS Flashcards
Bacteria
(formerly_______)
eubacteria
Characteristics of bacteria
Procaryotic (no nuclear membrane) Unicellular
Free living
Composed of RNA and DNA
Multiply by binary fission
Archaea (formerly_____)
Kingdom_____
Procaryotes
Archaebacteria
Monera
BACTERIAL MORPHOLOGY
SIZE:
0.2 – 2.0 µm by 1-10 µm
Size
Staphylococcus aureus -
Escherichia coli –
Thiomargarita namibiensis
0.5-1.5 µm in diameter
2 µm in length
100-750 µm
Bacteria
Shapes
SHAPE: spherical, rod-shaped, spiral
Bacteria arrangement
Cocci
Bacilli
Spiral
– sphere-shaped bacterium
Coccus
COCCI
diplococci
staphylococci
streptococci
tetrad
octad (sarcina)
– rod-shaped bacterium
Bacillus
BACILLI
in singles
diplobacilli
streptobacilli
coccobacilli
palisade (fence-like)
– rigid, helical cell wall, single flagella at each end
Spirillum
– corkscrew, axial filaments/internal flagella
Spirochete
Procaryotic cells have three architectural regions
________(proteins attached to the cell surface) in the form of flagella and pili;
________ consisting of a capsule, cell wall and plasma membrane;
________that contains the cell genome (DNA) and ribosomes and various sorts of inclusions.
appendages
cell envelope
cytoplasmic region
Filamentous protein attached to the cell surfaces that provide swimming movement
Flagella
Parts of a flagella
Filament
Hook
Basal body
Rotates to move (360)
Flagellum
H antigen
Hauch
Flagellin
Flagellar Arrangement
(a) Monotrichous
(b) Amphitrichous
(c) Lophotrichous
(d) Peritrichous
______have flagella which project in all directions.
______rotation of flagellar motors results in random re-orientation for the bacterium, but ______rotation produces approximate straight-line motion.
E. coli
Clockwise (CV)
counter-clockwise (CC)
Internal Flagella
Filaments
Axial Filaments
Periplasmic filaments
enclosed between cell wall & cell membrane of spirochetes
Motility (corkscrew fashion)
Internal flagella
•_____ affect critical biological functions including nutrient acquisition, motility, dispersion, stress resistance, and interactions with other organisms.
Shapes
Filamentous
Some of them form branching filaments resulting in a network of filaments called_____
mycelium
Sometimes slightly flatten when they are adjacent to one another
Cocci
Many spirilla are rigid and capable of movement especially group of
______are long, slender, and flexible
Spirochetes
DIPLOCOCCI
Examples
• Streptococcus pneumoniae
• Moraxella catarrhalis
• Neisseria gonorrhae
TETRADS
• Aerococcus
• Pediococcus
• Tetragenococcus
STREPTOCOCCI
Cocci in chains
• Streptococcus pyogenes
• Streptococcus agalactiae
STAPHYLOCOCCI
Cocci in clusters
• Staphylococcus aureus
SARCINA
Cocci in cubes consisting of eight cells
• Sarcina ventriculi
• Sarcina ureae
Cocci in chains
STREPTOCOCCI
Cocci in clusters
STAPHYLOCOCCI
Cocci in cubes consisting of eight cells
SARCINA
BACILLI
Most bacilli appear as…
single rods
DIPLOBACILLI
• Coxiella burneti
• Moraxella bovis
• Klebsciella rhinoscleromatis
Appear in pairs after division
DIPLOBACILLI
SINGLE ROD
• Bacillus cereus
Arranged in chains as the cells divide in one plane
STREPTOBACILLI
STREPTOBACILLI
• Streptobacillus moniliformis
Short and stumpy that they appear ovoid
They look like coccus and bacillus
COCCOBACILLI
COCCOBACILLI
• Haemophilus influenzae
• Gardnerella vaginalis
• Chlamydia trachomatis
Curved bacteria that can range from a gently-curved shape to a corkscrew-like spiral
SPIRILLA
Comma shaped bacteria with less than one complete turn or twist in the cell
VIBRIO
VIBRIO
• Vibrio cholerae
Rigid spiral structures, spirillum with many turns can superficially resemble spirochetes
They do not have outer sheath and endoflagella but have typical bacterial flagella
SPIRILLUM
SPIRILLUM
• Campylobacter jejuni
• Helicobacter pylori
• Spirillum winogradskyi
Have a helical shape and flexible bodies, move by means of axial filaments which look like flagella contained beneath a flexible external sheath, but lack typical bacterial flagella
SPIROCHETES
SPIROCHETES
• Leptospiral spp.
• Treponema pallidum
• Borrelia recurrentis