Explain what is meant by "active transport"? (3)

Answer: "The movement of molecules across a membrane from an area of lower to higher concentration. This process requires energy which is supplied in the form of ATP from respiration"Explain: concentration of a molecule = The number of molecules per specific area. *** insert diagram ***If you have a cell membrane - Inside the cell, there are 5 molecules and on the outside, there are 2 molecules (say both areas are the same size) — the Inside the cell with 5 will have a higher concentration. If one of the molecules on the outside of the cell moves into the cell - this is active transport as it is moving from an area of fewer to more. As this is not passive diffusion, it requires energy. This energy can be made in respiration through chemical reactions, This energy is the power source fo active transport.