Active Transport And Osmosis Flashcards
How many villi are there in the small intestine?
Millions
Where are villi located?
In the small intestine
How are villi specialised to make the absorption of digested food quicker into the blood?
The increase the surface area of the intestines, only have one layer of surface cells and have a very good blood supply
What is active transport?
The movement of molecules against a concentration gradient
Why does having root hair cells mean plants can absorb more water and mineral ions?
They have a bigger surface area
Why do plants use active transport to get mineral ions and water from the soil?
The concentration of mineral ions and water is usually higher in the root hair cell than the soil so only active transport would work
What does active transport require to work?
Energy from respiration
When is active transport used in humans?
It’s used in the gut when there is a low concentration of nutrients in the gut but a high concentration of nutrients in the blood
What is osmosis?
The movement of water molecules across a partially permeable membrane from a region of high water concentration to a region of low water concentration
What is a partially permeable membrane?
A membrane with very small holes
What direction does osmosis happen?
Both ways because molecules move randomly
What is the underneath of the leaf?
An exchange surface covered in stomata to let carbon dioxide diffuse through
What diffuses out of the stomata?
Oxygen and water vapour
