Membrane and Structure Function Chapter 7

A property of biological membranes that allows them to regulate the passage of substances across them.

Having both a hydrophilic and hydrophobic region

A channel protein in the plasma membrane that specifically facilitates the diffusion of free water across the membrane

The spontaneous movement of a substance down its concentration gradient and electrochemical gradient from a region where it is more concentrated to a region where it is less concentrated

A region along which the density of a chemical substance increases or decreases

The diffusion of free waqter across a selevtively permeable membrane

The diffuion of a substance across a biological membrane with no expenditure of energy

The ability of a solution surrounding a cell to cause that cell to gain or lose water

Regulation of solute concentrations and water balance by a cell or organism

The force directed against a plant cell wall after the influx of water and swelling of the cell due to osmosis.

A phenomenon in walled cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall; occurs when the cell loses water to a hypertonic environment

The passage of molecules or ions fown their electrochemical gradient across a biological membrane with the assistance of specific transmsmbrane transport protein, requiring no energy expenditure

The difference in voltage across a cell's plasma membrane due to the differential distribution of ions

The coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient.

A molecule that binds specifically to another molecule, usually a larger one