Active Transport

Question 1

What are root hairs specialised to do?

Answer 1

Absorb water and minerals

Question 2

How are root hairs specialised to do this?

Answer 2

1) the cells on the surface of plant roots grow into long hairs which stick out into the soil
2) this gives the plant a big surface area for absorbing water and mineral ions from the soil
3) most of the water and mineral ions that get into a plant absorbed by the root hair cells

Question 3

What is active transport

Answer 3

When a substance is absorbed against a concentration gradient ie. from a lower to a higher concentration

Question 4

How do root hairs take in minerals using active transport?

Answer 4

The concentration of minerals is usually higher in the root hair cell than in the soul around it. So normal diffusion doesn’t explain how minerals are taken up into the root hair cell as they should go the other way. Active transport allows the plant to absorb minerals from a very dilute solution against a concentration gradient. This is essential for its growth. But active transport needs energy from respiration to make it work.

Question 5

Active transport in the gut

Answer 5

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. When there’s a higher concentration of glucose and amino acids in the gut they diffuse naturally into the blood. BUT- sometimes there’s a lower concentration of nutrients in the gut then there is in the blood. So the concentration gradient is the wrong way, but active transport allows nutrients to be taken into the blood.