Diffusion

Semi-permeable membrane

A membrane that allows some particles to pass through, such as oxygen and carbon dioxide.

Selectively permeable membrane

A membrane that "chooses" what passes through, like water.

Diffusion

The process by which particles spread from an area of higher concentration to an area of lower concentration.

Active transport

The movement of molecules from low to high concentration, requiring ATP and a carrier protein.

Endocytosis

The process of bringing substances into the cell.

Isotonic

A solution with the same concentration of solutes as found in the cell, maintaining normal cell shape.

Hypotonic

A solution with a lower concentration of solutes than in the cell, causing cells to plump up as water enters.

Hypertonic

A solution with a higher concentration of solutes than in the cell, leading to water loss and cell shrinkage.

Facilitated diffusion

The passive transport of molecules that cannot pass through the lipid layer, using proteins.

Simple diffusion

The process by which noncharged molecules, like oxygen and carbon dioxide, pass through the lipid layer.

Osmosis

The movement of water across a membrane due to differing water concentrations on each side.

Exocytosis

The process of substances exiting the cell.

Passive transport

A type of membrane transport that does not require energy to move substances across cell membranes.

Mitosis

The process of chromosome replication and segregation, resulting in two identical nuclei for cell division.

Passive transport mechanisms

Methods of transport including diffusion, osmosis, and facilitated diffusion.

Active transport mechanisms

Methods of transport including active transport, endocytosis, and exocytosis.