What are three examples of passive transport? Active Transport?
Passive transport:
1. Simple diffusion - movement of molecules from an area of high concentration to an area of low concentration, without the use of energy.
2. Facilitated diffusion - movement of molecules across a cell membrane through protein channels, also without the use of energy.
3. Osmosis - movement of water molecules across a selectively permeable membrane from an area of high water concentration to an area of low water concentration.
Active transport:
1. Sodium-potassium pump - uses ATP energy to pump sodium ions out of the cell and potassium ions into the cell against their concentration gradients.
2. Proton pump - uses ATP energy to pump protons across a membrane, creating a hydrogen ion gradient.
3. Endocytosis - process in which cells engulf external materials by wrapping the plasma membrane around them and forming a vesicle for transport into the cell.