B3 - Active transport

Root hairs are specialised for absorbing water and minerals
1. The cells on the surface of plant roots grow into long hairs which stick out into the soil. This gives the plant a big surface area for absorbing water and mineral ions from the soil. Most of the water and mineral ions get into a plant are absorbed by the root hair cells.
Root hairs take in minerals using active transport
1. The concentration of minerals is usually higher in the root hair cell than in the soil around it so normal diffusion doesn't explain how minerals are taken up.
  1. Active transport allows the plant to absorb minerals from a very dilute solution, against a concentration gradient. This essential for growth. It needs energy for respiration to make it work.
    1. This also happens in humans - taking glucose from the gut and from kidney tubules
Active transport is used in the gut when there is a low concentration of nutrients in the gut but a high concentration of nutrients in the blood
1. When there's a higher concentration of glucose and amino acids in the gut they diffuse naturally into the blood
  1. But sometimes there's a lower concentration of nutrients in the gut than there is in the blood
    1. This means the concentration gradient is the wrong way.

Resource summary

	Created by Lily O'Brien over 7 years ago