- Both made up of pilin
-
Fimbriae
|
Pili
|
Differences
| |
Shorter
|
Longer
|
Help the cell to adhere to surface
|
Join bacterial cells for DNA transfer
|
Distributed evenly around the cell (
from several to hundreds)
|
Only one or two per cell
|
Similarities
| |
· Made up of protein pilin
· Shorter and thinner than flagella
|
No.
|
Characteristics
|
Cilia
| |
1
|
Definition
|
Cilia are short, hair like appendages extending from
the surface of a living cell.
|
Flagella are long, threadlike appendages on the
surface of a living cell.
|
2
|
Number
|
Numerous
|
Less in Number
|
3
|
Length
|
Short and hair like organelle (5-10µ)
|
Long wipe like organelle (150µ)
|
4
|
Occurrence
|
Occurs throughout the cell surface.
|
Presence at one end or two ends or all over the
surface.
|
5
|
Cross section
|
Nexin arm present.
|
Nexin arm absent
|
6
|
Density
|
Many (hundreds) per cell
|
Few (less than 10) per cell
|
7
|
Beating
|
Cilia beat in a coordinated rhythm either
simultaneously (synchronous) or one after the other (metachronic).
|
They beat independent of each other.
|
8
|
Motion
|
Rotational, like a motor, very fast moving
|
Wave-like, undulating, sinusoidal, slow movement
compared to cilia
|
9
|
Found in
|
Eukaryotic cells
|
Eukaryotic and prokaryotic cells
|
10
|
Energy Production
|
Cilia use ‘kinesin’ which has an ATPase activity
that produces energy to perform the movement.
|
Flagella are powered by the proton-motive force by
the plasma membrane.
|
11
|
Functions
|
Helps in locomotion, feeding circulation, aeration,
etc.
|
Help mainly in locomotion only.
|
12
|
Examples
|
Cilia present in Paramecium
|
Flagella present in Salmonella
|
Difference between flagella and cilia
5) Cell wall
- Anything that is fit can pass through cell wall
- Function:
- Contributes to pathogenicity (teichoic acid and peptidoglycan)
- Classification into gram positive or gram negative
- Prevent rupture of bacteria cell
- Provide shape to bacteria
- Anchor for surface appendages ( flagella, cilia, pili)
- Withstand osmotic pressure
S.N.
|
Characteristics
|
Gram Positive
|
Gram Negative
|
1
|
Gram Reaction
|
Retain crystal violet dye and stain blue
or purple
|
Can be decolorized to accept
counterstain (safranin) and stain pink or red
|
2
|
Cell Wall
|
Cell Wall is 20-30 nm thick.
|
Cell Wall is 8-12 nm thick.
|
3
|
Cell Wall
|
The wall is Smooth.
|
The wall is wavy.
|
4
|
Peptidoglycan Layer
|
Thick (multilayered)
|
Thin (single-layered)
|
5
|
Teichoic Acids
|
Present in many (contribute to pathogenicity)
|
Absent
|
6
|
Periplasmic Space
|
Absent
|
Present
|
7
|
Outer Membrane
|
Absent
|
Present
|
8
|
Porins
|
Absent
|
Occurs in Outer Membrane
|
9
|
Lipopolysaccharide (LPS) Content
|
Virtually None
|
High (contribute to pathogenicity)
|
10
|
Lipid and Lipoprotein Content
|
Low (acid-fast bacteria have lipids linked to
peptidoglycan)
|
High (because of presence of outer membrane)
|
11
|
Mesosomes
|
Quite Prominent
|
Less Prominent
|
12
|
Flagellar Structure
|
2 rings in basal body
|
4 rings in basal body
|
13
|
Toxin Produced
|
Exotoxins
|
Endotoxins or Exotoxins
|
14
|
Resistance to Physical Disruption
|
High
|
Low
|
15
|
Cell Wall Disruption by Lysozyme
|
High
|
Low (requires pretreatment to destabilize outer
membrane)
|
16
|
Susceptibility to Penicillin and Sulfonamide
|
High
|
Low
|
17
|
Susceptibility to Streptomycin, Chloramphenicol and
Tetracycline
|
Low
|
High
|
18
|
Inhibition by Basic Dyes
|
High
|
Low
|
19
|
Susceptibility to Anionic Detergents
|
High
|
Low
|
20
|
Resistance to Sodium Azide
|
High
|
Low
|
21
|
Resistance to Drying
|
High
|
Low
|