Phagocytes can't bind and engulf the capsule, so encapsulated bacteria are protected from ingestion and destruction. For example, Streptococcus pneumonia , a common cause of pneumonia, won't cause disease when not encapsulated. Barrier to some disinfectants, toxins, and antibiotics. Appendages are structures that are attached to the outside of the bacterial cell. These include flagella, pili, and axial filaments.
Flagella are long filaments made up of the protein flagellin.
Rotation of flagella propels the bacteria forward. Bacteria are attracted by sugars, proteins and amino acids and will swim toward them. They are repelled by some substances and will swim away from them. This is known as chemotaxis. Bacteria may have one, two, many, or no flagella at all.