Question

Are pili and fimbriae mainly involved in the motility of bacterial cells?

Answer 1

Fimbriae

1. Fimbriae are the thin protein tube which originates from the cytoplasmic membrane in many bacteria.
2. It is bristle-like short fibres present on the surface of bacteria made of fimbrillin protein.
3. They are present in both Gram-negative as well as Gram-positive bacteria.
4. Around 200 to 400 fimbriae are present per bacterial cell.

Pili

1. Pili are hair-like long tubular microfibers which are present on the surface of bacteria.
2. They are present in Gram-negative bacteria only.
3. They are made of pilin protein and are present from 1 to 10 in number per cell.

Functions

1. Pili and fimbriae help in cell motility.
2. Other functions include cell-cell interactions and DNA uptake.
3. Pili aids in adherence to the surface resulting in virulence and infection.