active transport

• Sometimes substances need to be absorbed against a concentration Gradient .I.E from a lower to higher concentration. This process is referred to as active transport.
• Cells on plant roots grow into hairs.

  Each branch of a root is covered in these microscopic hairs.

  This gives the plant a large surface area for absorbing water and mineral ions from soil.

  Plants need these mineral ions for growth.

  The concentration of minerals is usually higher in root hair cells than in the soil around them.

  So the root hair cells can't use diffusion to take up minerals from the soil.
• Root hairs take in minerals through active transport.


  Allows the plant to absorb minerals from a very dilute solution against a concentration Gradient. This is essential for growth.
• Active transport needs ENERGY from respiration to make it work.
• We need active transport to stop us from starving.
• 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 is Ohio concentration of glucose and amino acids in the gut, they diffuse naturally into the blood
• But sometimes there is a lower concentration of nutrients in the gut than there is in the blood. This means that the concentration ingradient is the wrong way. The same process used in plant roots is used here. Active transports allows to be taken into the blood despite the fact that the concentration ingradient is the wrong way, this means that glucose can be taken into the bloodstream. When its concentration in the body is already higher than in the gut. It can then be transported to cells where it is stored for respiration