What happens in active transport that makes it so different than diffusion

Although both use a carrier proteins, however facilitated diffusion moves down a concentration gradient rather than against one like active transport, so it doesn't require metabolic energy. Hope this helps out

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.