A dimeric kinesin-1 molecule has 8-nm steps and can move at rates of about 1 µm/sec. Olympic 100-meter sprinters typically run at about 180 steps per minute and can reach speeds of about 42 km/h. With the same step size, if the Olympic runner had a step frequency of a kinesin-1 molecule, how fast could she run? Write down your answer in km/h, e.g. 52 km/h.

Question

Quizplus · Accepted Answer

The step frequency of kinesin-1 is about 125 steps per second [= (1000 nm/sec)/(8 nm/step)], while that of a runner is only about 3 steps per second [= (180 steps/min)/(60 sec/min)]. If the runner had the step frequency of the kinesin motor, they could run at 1750 km/h (= 42 km/h × 125/3). This is a supersonic speed, faster than bullets and regular passenger planes.

A Dimeric Kinesin-1 Molecule Has 8-Nm Steps and Can Move