In a vascular plants , specialized root hairs on the roots of the plant are responsible for taking up water and nutrients . the water taken up by the roots of the plants can then be transported to the rest of the plant through the plants ?

I believe the answer to be xylem.

Explanation:

Here is my source: https://www.untamedscience.com/biology/plants/transport-in-plants/

This seems to be a general consensus, I am sorry that I cannot be 100% sure.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.