EVERYDAY SCIENCE

Detailed explanation-1: -Fimbriae and pili are extensions of the cytoplasmic membrane and are made up of an oligomeric protein known as pilin. They are hair-like appendages present on the bacterial cell wall similar to flagella. They are involved in bacterial conjugation, attachment to the surface and motility.

Detailed explanation-2: -Pili or fimbriae are protein structures that extend from the bacterial cell envelope for a distance up to 2 m (Figure 3). They function to attach the cells to surfaces. E. coli cells can have up to 300 of these organelles.

Detailed explanation-3: -Pili are short, hair-like structures on the cell surface of prokaryotic cells. They can have a role in movement, but are more often involved in adherence to surfaces, which facilitates infection, and is a key virulence characteristic.

Detailed explanation-4: -Cell-wall anchoring of monomeric pilins In fact, when the SpaA pilin motif lysine is mutated, pilus polymerization is abolished, but the mutant protein is avidly anchored to the cell wall [21, 23]. In the absence of SpaA, the minor pilins SpaB and SpaC are also linked to the cell wall [21].

Detailed explanation-5: -One class of pili, known as type IV pili, not only allow for attachment but also enable a twitching motility. They are located at the poles of bacilli and allow for a gliding motility along a solid surface such as a host cell.