Flagella
- Most motile bacteria move around using flagella (s. flagellum).
- Filamentous locomotor appendages extending beyond the membrane and cell wall.
- They are Thin, rigid structures, about 20 nm long and up to 15-20 meters long.
- So thin that they can be directly observed with a light field microscope, but they need to be coloured with special methods designed to increase the thickness.
Fimbriae
- Fimbriae are filamentous structures composed of protein that extend from the surface of a cell and can have many functions.
- Fimbriae are short, thin, hair-like performances that are thinner than flagella and should not participate in the movement.
- A cell that can be covered with up to 1000 fimbriae.
- They are only visible under an electron microscope due to their small size.
Similarities between Flagella and Fimbriae
- Flagella and Fimbriae both are filamentous in structure.
- In both Gram positive and Gram negative Flagella or Fimbriae may be present.
- Both are present in cell surface of bacteria.
- Flagella as well as Fimbriae both are made up of Proteins but ingredient may varies.
Difference between Fimbriae and Flagella
| Factors | Fimbriae | Flagella |
|---|---|---|
| Structure | Bristle-like filamentous structure on surface of some bacteria. | Whip-like filamentous structure on surface of some bacteria. |
| Origin | They are external in origin. | They are internal in origin. |
| Originated From | Fimbriae are originated from the cell wall. | Flagella are originated from membrane of cytoplasm. |
| Helical Nature | Fimbriae are non-helical in nature. | Flagella are helical in nature. |
| Straight Nature | Fimbriae are straight. | Flagella are not straight. |
| Made up of which protein | Fimbriae are made up of specific protein called fimbrilin or pilin protein. | Flagella are made up of specific protein called flagellin protein. |
| Rigidity | Fimbriae are less rigid than flagella. | Flagella are more rigid than fimbriae. |
| Function | Attachment of surfaces is the main function of fimbriae. | Locomotion is the main function of flagella. |
| Role in motility | They do not have any role in motility. | They have main role in motility. |
| Role in surface attachment | Fimbriae have main role in surface attachment. | Flagella do not take part in surface attachment. |
| Diameter | Fimbriae are thin in diameter as compare to flagella. | Flagella are thick in diameter as compare to Fimbriae. |
| Length | They are shorter in length than flagella. | They are longer in length as compared to fimbriae. |
| Range of Length | Fimbriae may varies in length from 0.03 to 0.14 μm. | Flagella may varies in length from 15 to 20 μm. |
FAQs – Fimbriae vs Flagella
1. Are fimbriae used for motility?
Ans: No. Fimbriae are not used for motility. Generally fimbriae are used for surface attachment.
2. What is main function of fimbriae function?
Ans: Attachment of surfaces is the main function of fimbriae not motility.
References
- https://www.easybiologyclass.com/difference-between-flagella-and-fimbriae-of-bacteria-a-comparison-table
- https://microbenotes.com/flagella-and-pili-fimbriae/
- https://microbiologynote.com/fimbriae-and-pili/
- https://www.differencebetween.com/difference-between-pili-and-vs-flagella/
