active transport

• what is active transport?

  movement of molecules against their concentration gradient (from an area of lower concentration to an area of higher concentration). it is an active process that requires energy from the cell via cellular respiration. it always takes place across a membrane
• where does the energy for active transport come from?

  cellular respiration - mitochondria break down glucose to release energy
• what is an example of active transport?

  a plant needs to absorb water and mineral ions from the soil to survive. to do this, they have a network of roots. around the outside of the roots are special cells called root hair cells. these cells absorb the water and mineral ions from the soil. they are adapted to this by having long hair like protrusions that stick out into the soil, to give the cells a large surface area for absorption. the ions are of a higher concentration inside the cell, so they can't be absorbed via diffusion. instead, they have to use energy to absorb them via active transport against the concentration gradient. the root hair cells also have lots of mitochondria to generate the energy needed for active transport through cellular respiration,