B1 Active Transport (page 19) Flashcards
What is Active Transport?
Sometimes substances need to be absorbed against a concentration gradient ie. from a lower to a higher concentration. This is Acive Transport.
What do Root hairs take in?
Minerals and Water.
Explain what happens on plant roots when they grow?
the cells on plant roots grown into hairs, which stick out into the soil.
Each branch of the hairs will be covered in millions of what?
microscopic hairs.
the millions of microscopic hairs gives the plant a large surface area for absorbing what?
water and mineral ions from the soil.
What do Plants need mineral ions for?
for healthy growth.
Is the concentration of minerals higher in the root hair cells or in the soil around them?
the concentration of minerals is usually higher in the root hair cells.
Can the root hair cells use diffusion to take up minerals from the soil?
No, as the concentration of minerals is the root hair is higher than in the soil.
Root Hairs take in minerals using what?
Active Transport.
Minerals should move out of the root hairs,how do they do this by?
Then the cells must use another method to draw them in. (active transport)
Active transport allow the plant to what?
it allows the plant to absorb minerals from a very dilute solution, against a concentration gradient. This is essential for it’s growth. But active transport needs ENERGY from RESPIRATION to make it work.
Active transport also happens in humans, give an example?
taking glucose from the gut and from the kidney tubules.
Why do Humans need Active Transport?
to stop us starving.
When and where is Active Transport used in humans?
Active transport is used in the gut when there is a lower concentration of nutrients in the gut, but a higher concentration of nutrients in the blood.
When there’s a higher concentration of glucose and amino acids in the gut, what happens?
they diffuse naturally into the blood.
What happens if there is a lower concentration of nutrients in the gut than there is in the blood?
This means the concentration gradient is the wrong way around, so Active Transport is then used, (the same process used in plant roots is used in humans) (see diagram on page 19).
What do Active transport allow in humans?
it allows nutrients to be taken into the blood, despite the fact that the concentration gradient is the wrong way.
This means that glucose can be taken into the bloodstream when it’s concentration in the blood is already higher than in the gut. It can then be transported to cells where it’s used for respiration (see page 54).
What is the important difference between active transport and diffusion?
Active transport uses energy. (imagine a pen of sheep in a field. If you open the pen, the sheep will happily diffuse from the area of higher sheep concentration into the field, which has a lower sheep concentration - you won’t have to do a thing. - To get them back in the pen though, you’ll have to put in quite a bit of energy).
What is the purpose of active transport in the gut? (1 mark).
Active transport allows nutrients such as glucose to move from a lower concentration in the gut to a higher concentration in the blood (against te cocentration gradient) 1 mark