Prokaryotes

Gram positive

Gram reaction

stain purple

Peptidoglycan layer

many layer

Teichoic acid

present

Periplasmic space

Absent

Outer membrane

Absent

Lipopolysaccharide

none

Gram negative

Gram reaction

stain red

peptidoglycan layer

many layer

Teichoic acid

absent

outer membrane

present

Periplasmic space

present

Lipopolysaccharide

high

Glycocalyx

organized

capsule

Unorganized

Slime layer

Made of sugar

EPS

Functions

Protection from phagocytosis

Attachment to various surface

Protect cell from dehydration

Flagella

Number & Arrangement

Monotrichous

one flagellum

Amphitrichous

one flagellum at each end of cell

Lophotrichous

Cluster of flagella at one or both ends

Petritrichous

Spread over entire surface of cell

Type of motility

Run or Swim

moves in one direction for a length of time
of time

Tumbles

runs interrupted by periodic,abrupt, random changes in direction
abrupt, random changes in
direction

Swarm

rapid wavelike movement

Axial Filaments

Bundle of fibrils arises at the end of the cell

spiral around cell

Fimbriae

at the pole of the cell

evenly dsitributed over entire surface of the cell

a few to several hundred

Pili

Longer than fimbriae

only one or two per cell

join bacterial cells in preparation for the transfer of DNA

Cocci

Diplococci

Sreptococci

Staphyllococci

Tetradcocci

Sarcianae

Bacilli

Diplobacilli

Streptobacilli

Pallisades

Spiral

Spirullum

Spirochete

Additional

Unusual

Star shape

Square

Triangular

Pleomorphic

No fixed shape

Smallest

0.3 μm

Average

0.6 μm

very large

600 x 80 μm