active transport allows cells to move substances from area of low conc to area of high conc against conc gradient so the cells can absorb ions from very dilute solutions and also enables cells to move substances such as sugars and ions, from one place to another through cell membrane
energy is needed for active transport system to carry molecule across membrane and then return to its original position- this energy is produced during cell respiration.
if a cell respires and releases a lot of energy, it can carry out lots of active transport for example root hair cells in plants and cells lining the gut
cells involved in a lot of active transport usually have many mitochondria to release energy they need
mineral ions in soil such as nitrate ions are usually found in very dilute solutions which are more dilute than the solution within plant root hair cells. by using active transport, plants can absorb these mineral ions even though it is against a conc gradient
sugar, such as glucose is always actively absorbed out of your gut and kidney tubules into your blood- this often done against large conc gradient
glucose needed for cell respiration so it is important to get as much as possible out of the gut. the conc of glucose in your blood is kept steady so sometimes it is higher than conc of glucose in your gut- active transport is used to move glucose from gut into blood against the conc gradient
