Active transport/Uptake
Up take of minerals by the root hair cell is very
important for a plant's growth. However, it does not
always uses diffusion. Plant root hair cells are specialised cells. They grow into long
thin 'hair', giving the plant a large surface to absorb minerals and water. When the concentration of minerals is higher in the root hair cell than the surrounding soil, it is unable to absorb
these using diffusion. The plant instead uses a method called ACTIVE
TRANSPORT for absorption. This uptake of minerals is against the concentration
gradient and the plant has to spend energy to do this. The energy used come from respiration. Active
transport also happens in animals. For
example, in humans the uptake of glucose from the gut and from the kidney tubules. See
below! Animation of root hair cell absorbing
minerals.
Movement
of
Minerals across Root Hair Cells by Active Transport.
After a large
meal, your gut has lots (high concentration) of amino acids, fatty acids, glycerol
and glucose. These get absorbed into
the blood stream by simple diffusion. However, when there are less (low concentration) nutrients in the gut then
in the blood and your body needs them, these are then absorbed
by active transport. .
Tags:Active transport, Uptake, Diffusion