Active Transport in cells???Someone....I need help???

Question

Okay I need a lil help on understanding active transport in cells....also where is active transport used in the body?

Answer 1

Active transport is distinguished from passive transport in that is requires ATP energy expenditure on the part of the cell while passive (diffusion or osmosis) does not. Active transport include the sodium - potassium pump, phagocytosis (cellular eating as in Ameoba), and pinocytosis (cellular drinking).

Answer 2

The guy above me's answer is incredibley complicated. I'll explain it at GCSE level, as that's as far as I am right now :P.

Active transport is when dissolved minerals pass across a partially permeable cell membrane. It works against the concentration gradient (the C.G. is when it goes from high concentration to low concentration. Think of a smell; it gradually diffuses [spreads] out). I.e. active transport is the molecules going from an area of low concentration to high concentration. This means it requires a lot of energy.



An example around the body is the villi in our gut. The villi take in lots of nutrients via active transport so the food can't diffuse [spread] into them. This means that they take in as much as possible. If they didn't use active transport, they'd end up with less food molecules than outside the villi - but instead they end up with lots inside them, and less outside. They take in things like amino acids, minerals and vitamins.

Hope that helped :)