Final answer:
Bacteria use molecules called adhesins, such as proteins and carbohydrates, to attach to the surface of cells during colonization. These adhesins bind to specific receptors on host cells, which are glycoproteins.
Step-by-step explanation:
Bacteria use molecules called adhesins to attach to the surface of cells during colonization. Adhesins are either proteins or carbohydrates found on the surface of certain pathogens, such as fimbriae and flagella of bacteria, cilia of protozoa, and capsids or membranes of viruses. They bind to specific receptors on host cells, which are glycoproteins.
Protozoans can also use hooks and barbs for adhesion, while spike proteins on viruses enhance viral adhesion. Additionally, certain bacterial pathogens can produce glycocalyces (slime layers and capsules) with high sugar and protein content, allowing them to attach to cells.
Overall, adhesins and other surface appendages like fimbriae and pili help bacteria attach to cells and surfaces, aiding in the colonization process.