Final answer:
Treadmilling is a mechanism in actin filaments where assembly and disassembly occur simultaneously, allowing for continual remodeling. It is important for understanding key functions of actin including cell motility, muscle contraction, and cell division.
Step-by-step explanation:
Treadmilling is a mechanism in which actin filaments undergo constant assembly at one end and disassembly at the other end, resulting in a net movement of actin subunits along the filament. This process is important for understanding the key functions of actin because it allows the actin filaments to continuously remodel and change their length. This dynamic behavior is essential for processes such as cell motility, muscle contraction, and cell division.