Tranpsort in cells

What is diffusion?

The movement of molecules (e.g., oxygen, carbon dioxide) from an area of high concentration to an area of low concentration, down the concentration gradient.

What is osmosis?

The diffusion of water through a partially permeable membrane from an area of high water concentration to an area of low water concentration.

What is active transport?

The movement of molecules from an area of low concentration to an area of high concentration, against the concentration gradient, requiring energy (ATP).

What is ATP

ATP, or adenosine triphosphate, is like a battery for cells. It stores energy that cells need to do their work. When cells need energy, they break a part of ATP to release that energy, kind of like using up power from a battery.