Prokaryotes
Size
very large
600 x 80 μm
Average
0.6 μm
Smallest
0.3 μm
Shape
Additional
No fixed shape
Pleomorphic
Unusual
Triangular
Square
Star shape
Spiral
Spirochete
Spirullum
Bacilli
Pallisades
Streptobacilli
Diplobacilli
Cocci
Sarcianae
Tetradcocci
Staphyllococci
Sreptococci
Diplococci
Structure external to cell wall
Pili
join bacterial cells in preparation for the transfer of DNA
only one or two per cell
Longer than fimbriae
Fimbriae
a few to several hundred
evenly dsitributed over entire surface of the cell
at the pole of the cell
Axial Filaments
spiral around cell
Bundle of fibrils arises at the end of the cell
Flagella
Type of motility
Swarm
rapid wavelike movement
Tumbles
runs interrupted by periodic,abrupt, random changes in direction
abrupt, random changes in
direction
Run or Swim
moves in one direction for a length of time
of time
Number & Arrangement
Petritrichous
Spread over entire surface of cell
Lophotrichous
Cluster of flagella at one or both ends
Subtopic
Amphitrichous
one flagellum at each end of cell
Monotrichous
one flagellum
Glycocalyx
Functions
Protect cell from dehydration
Attachment to various surface
Protection from phagocytosis
Made of sugar
EPS
Unorganized
Slime layer
organized
capsule
Cell wall
Gram negative
high
outer membrane
absent
peptidoglycan layer
stain red
Gram positive
Lipopolysaccharide
none
Outer membrane
Periplasmic space
Absent
Teichoic acid
present
Peptidoglycan layer
many layer
Gram reaction
stain purple
