Question

A molecular motor moves along a microtubule track in steps of 100 Å displacements. The motor hydrolyzes one molecule of ATP per step. The motor operates under conditions where the free-energy change for ATP hydrolysis is –60 kJ•mol–1. What is the maximum resistive force against which the motor can move cargo?

Answer 1

Answer: F= 10⁻¹¹ N

Explanation:

We are given that a molecular motor moves in steps of 100  Å.

The energy change for ATP hydrolysis is –60 kJ•mol⁻¹

Now we have to find the maximum resistive force against which motor can move cargo.

So the force will be equal to the energy value divided by the distance in meters.

F= $\frac{-60}{100*10^{-10} }$ = −6000000000

Ignoring the minus sign.

And for one molecule of ATP per step, the value is divided by Avogadro's number.

F= $\frac{6000000000}{6.02*10^{23} }$

F= 10⁻¹¹ N