What separates active transport from passive transport?

Answer 1

Active transport is when a cell needs to use energy in or to let substances pass in through or out or its cell membrane or cell wall. Passive transport requires to energy at all making substances like water easy to let pass through.

Answer 2

Active transport requires energy input in the form of ATP to move molecules against their concentration gradient, while passive transport does not require energy and moves molecules along their concentration gradient. Active transport typically involves the use of transport proteins called pumps, while passive transport involves channels or carriers that facilitate movement without requiring energy.