Active and passive transport

Active transport requires energy to move substances against their concentration gradient, while passive transport does not require energy and moves substances along their concentration gradient.

Active transport and passive transport.

Facilitated diffusion is a type of passive transport that uses transport proteins to help move substances across the cell membrane without using energy.

Endocytosis is an active transport process where cells engulf substances from the outside environment, bringing them into the cell.

Exocytosis is an active transport process where cells expel materials by vesicles fusing with the cell membrane.

Membrane proteins facilitate the transport of substances across the cell membrane, either by acting as channels or carriers.

A semi-permeable membrane allows certain substances to pass through while blocking others, crucial for maintaining homeostasis in cells.

Osmosis is the passive transport of water molecules across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

The sodium-potassium pump is an example of active transport that moves sodium ions out of the cell and potassium ions into the cell against their concentration gradients.

A concentration gradient is the difference in the concentration of a substance across a space, which drives the movement of substances during transport.