Active transport

• Root hair cells take in minerals and water
• Root hair cells have mini hairs on all of their roots, which gives it a large surface area. This is good for absorbing water and mineral ions from the soil. Mineral ions are needed for healthy growth. Also, the concentration of minerals is usually higher in the root hair cells than in the soil around them so they can't use diffusion to take up minerals from the soil
• Root hair cells take in minerals using active transport
• Minerals should move out of the root hairs if they followed the rules of diffusion. The cells must use another method to draw them in. This is called active transport
• Active transport 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, for example in taking glucose from the gut and from the kidney tubules
• 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's a higher concentration of glucose and amino acids in the gut they diffuse naturally into the blood. But sometimes there's a lower concentration of nutrients in the gut than there is in the blood. This means the concentration gradient is the wrong way.
• Active transport is also used in plant roots
• Active transport 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.
• Active transport requires energy but diffusion doesn't