Active transport Flashcards
What is active transport?
The movement of molecules across a cell membrane into a region of higher concentration (against a concentration gradient), assisted by enzymes and requiring energy from respiration.
What is a root hair cell specialised for?
Absorbing water and minerals.
Where are root hair cells located?
On the surface of the plant, roots grow into long ‘hairs’ which stick out in the soil.
How is a root hair specialised for the absorption of water and minerals?
The long hairs stick out in the soil, giving it a big surface area.
How do root hair cells take in minerals?
Using active transport.
Why do root hair cells use active transport instead of normal diffusion?
Because the concentration of minerals is usually higher in the root hair cell than in the soil around it.
What does active transport allow a plant to do?
It allows plants to absorb minerals from a very dilute solution against a concentration gradient (this is essential for its growth).
Where does active transport happen in humans?
When taking glucose from the gut and from the kidney tubules.
When is active transport used in the gut?
When there is a low concentration of nutrients (glucose and amino acids) in the gut, but a high concentration of nutrients in the blood.
What happens when there is a higher concentration of glucose and amino acids in the gut?
They diffuse naturally into the blood.
What does active transport allow in a human?
It allows nutrients to be taken into the blood.
