An active transport process by which large particles enter a cell.

In cells, solution in which the concentration of dissolved materials is higher in the solution surrounding the cell than the concentration inside the cell, which will shrink as water leaves the cell by osmosis.

The process resulting from a drop in turgor pressure as a result of water loss in a cell, causing the plasma membrane to shrink away from the cell wall.

A process requiring energy by which cells move materials against a concentration gradient.

A passive transport of materials, such as sugars and amino acids, across the plasma membrane by way of transport proteins.

An organelle of some protists such as Paramecium that collects excess water from the cell, then contracts and expels the water through a plasma membrane pore.

The internal pressure of a cell due to water held there by osmosis pressure.

In cells, solution in which the concentration of dissolved materials is lower in the solution surrounding the cell than the concentration inside the cell, which will swell and possibly burst as water enters the cell by osmosis.

A net, random movement of particles from an area of higher concentration to an area of lower concentration, eventually resulting in even distribution.

A channel proteins and carrier proteins embedded in the lipid bilayer of the plasma membrane; move ions and molecules across the membrane.

A condition of continuous movement but no overall change in concentration.

A membrane lipid having an organic section attached to a phosphate group.

The property of a plasma membrane that maintains the cell’s homeostasis by the taking in of needed substances, the elimination of wastes, and the prevention of harmful substances from entering.

An active transport process by which materials are expelled or secreted from a cell.

In cells, movement of particles across cell membranes requiring no expenditure of energy by the cell; examples are diffusion and osmosis.

Property of the plasma membrane wherein many similar molecules are free to move sideways within their lipid bilayer.

Diffusion of water molecules through a selectively permeable membrane depending on the concentration of solutes on either side of the membrane.