Active transport is the cellular mechanism that moves substances across a membrane against their natural concentration gradient, and it uses energy provided by ATP molecules to do so. This means the cell needs a reliable energy source, and that energy source is usually adenosine triphosphate, or ATP. Here's the thing — while simple diffusion and osmosis often move substances from areas of high concentration to low concentration, active transport must work in reverse or create new gradients. Every time a neuron fires, a kidney cell filters blood, or a muscle cell absorbs nutrients, active transport may be using energy provided by ATP molecules.
What Is Active Transport?
Active transport is a type of cellular transport that requires energy to move molecules or ions across a cell membrane. The movement can be **
