Explain/Teach these Concepts to a Friend

1. Why is kT considered the natural energy scale in cell biology?
2. Explain the importance of coordinating force generating mechanisms during cell motility.
3. Forces are generated in the eukaryotic cytoskeleton by two common mechanisms: stepping of molecular motor proteins (such as myosin) and assembly/disassembly of cytoskeletal filaments.  Which kinds of cell movements use each of these two mechanisms? 
   
   
4. Why are molecular motor proteins better suited to generate force for some cell movements and filament assembly better for others?