Cell-Transport

Concentration

The amount of solute in a solution.

Solute

The dissolved substance in a solution.

Solution

A mixture in which two or more substances are mixed evenly.

Concentration gradient

The gradual difference in the concentration of solutes in a solution between two regions.

Cell membrane

A biological membrane that separates and protects the interior of all cells from the external environment.

Lipid bilayer

A thin polar membrane made of two layers of lipid molecules, which forms the foundation of cell membranes.

Transmembrane proteins

Proteins that span the entire cell membrane, providing avenues for substances to cross the membrane.

Transport channels

Membranes are selective, allowing specific substances to move in and out of the cell.

Facilitated diffusion

The process of spontaneous passive transport of molecules across a membrane via specific transmembrane integral proteins.

Osmosis

The diffusion of water through a selectively permeable membrane.

Hypertonic solution

A solution that contains a higher concentration of solute compared to another solution, causing cells to lose water.

Hypotonic solution

A solution that contains a lower concentration of solute compared to another solution, causing cells to gain water and possibly burst.

Isotonic solution

Solutions that have the same solute concentration as another solution, allowing water to move in and out of cells at equal rates.

Exocytosis

A process where the cell expels materials in bulk by fusing a vesicle with the cell membrane.

Endocytosis

A cellular process in which substances are brought into the cell by engulfing them with the membrane.

Cytoskeleton

A network of fibers that helps provide structural support and shape to the cell.

Homeostasis

The ability of a cell to maintain stable internal conditions despite changes in the environment.

Cell adhesion proteins

Proteins that help cells stick to each other and maintain the structure of tissues.

Cell surface receptors

Proteins on the cell surface that receive and transmit signals from the outside environment.

Cell identity markers

Molecules on the cell surface that help identify the cell to others.

Contractile vacuoles

Organelles found in protists that help regulate water by collecting excess water and expelling it.

Turgor pressure

The pressure exerted by fluid in the central vacuole against the cell wall, helping maintain the structure of plant cells.