What is the difference between active and passive transport?
•Passive transport of molecules must occur in the presence of a selectively permeable membrane.
•The SPM allows the passage of some substances and not others, hence it is “selectively permeable” The process involved in passive transport is diffusion
•Active Transport requires energy to be expended by the cell to move molecules across the cell membrane.
•Animal cells have a much higher concentration of potassium ions (K+) and a much lower concentration of sodium ions (Na+) than their surrounding environment.
•How does the cell keep the balance without water moving into or out of the cell unwanted?
•Answer: the cell’s proteins in the membrane pump K+ and Na+ across the membrane as needed. This process requires energy.