Practice question

Kinesin-1 conventional motor transports cargo over long distances toward plus ends at velocities up to 1 micron per second. Heavy chain dimerization produces two motor heads coordinated via neck linker docking mechanism. Motility described as processive sliding or walking because motor maintains continuous association via at least one head bound at any moment preventing diffusion away from track essential for long range transport. ATP binding to leading head causes neck linker zipping toward plus end throwing lagging head forward to next binding site 8 nm ahead matching tubulin dimer repeat analogous to hand over hand stepping yet often simplified as sliding motion along filament surface maintaining electrostatic tethering via K loop. Interaction with microtubule via switch regions L8 L12. Tail associates with light chains binding cargo adaptors JIP Milton leading to activation by unfolding autoinhibition relieved only upon cargo binding preventing futile ATP consumption. This continuous attachment ensures efficient organelle movement without loss critical for axonal transport across meter long axons in larger mammals requiring high processivity.