Question

${10}^{-6}$Movement of a molecule across a typical plant cell (about 50 µm) takes approximately 2.5 s, at this rate can you calculate how many years it would take for the movement of molecules over a distance of 1 m within a plant by diffusion alone?

Answer 1

step -1: Diffusion is defined as movement of particles from a region of its higher concentration to the region of its lower concentration.

step -2: Diffusion depends on the concentration gradient and the size of the molecules. A molecule takes 2.5 seconds to move a distance of 50 µm.
50 µm is travelled in 2.5 seconds.
⇒ 1 µm is travelled in (2.5/50) seconds, i.e., 0.05 seconds.
⇒ 1 x ${10}^{-6}$ m is travelled in 0.05 seconds.
⇒ 1m is travelled in (0.05/ 1 x ${10}^{-6}$) seconds,
i.e., 5 x ${10}^4$ seconds.
Since, 3.15 x ${10}^7$ seconds is present in 1 year.
⇒ 5 x ${10}^4$ seconds is present in (5 x ${10}^4$/ 3.15 x ${10}^7$) year,
i.e., 1.587 x ${10}^{-3}$ year or 0.001587 year.