Exhibits selective permeability allowing some substances to cross it more easily than others

These proteins are bound to the surface of the membrane

The tendency for molecules to spread out evenly into the available space

The diffusion of water across a selectively permeable membrane

Transport vesicles migrate to the membrane, fuse with it, and release their contents

Amphipathic molecules that are the most abundant lipid in the plasma membrane

These proteins penetrate the hydrophobic core

As many molecules cross one way as cross in the other direction

Solute concentration is the same as that inside the cell; no net water movement across the plasma membrane

The cell takes in macromolecules by forming vesicles from the plasma membrane

This model states that a membrane is a fluid structure with a "mosaic" of various proteins embedded in it

These proteins allow passage of hydrophilic substances across the membrane

The diffusion of a substance across a biological membrane when it requires NO energy from the cell to make it happen

Solute concentration is greater than that inside the cell; cell loses water

A cell engulfs a particle in a vacuole

This steroid helps act as a buffer to restrain movement of phospholipids in warm temperatures and prevent tight packing in cool temperatures

These transport proteins have a hydrophilic channel that certain molecules or ions can use as a tunnel

Transport proteins speed the passive movement of molecules across the plasma membrane

Solute concentration is less than that inside the cell; cell gains water

Molecules are taken up when extracellular fluid is “gulped” into tiny vesicles

Membranes switch from a fluid to a solid state as temperatures do this

These transport proteins bind to molecules and change shape to shuttle them across the membrane

Moves substances against their concentration gradient
transport requires energy, usually in the form of ATP

The control of water balance, is a necessary adaptation for life in such environments

Binding of ligands to receptors triggers vesicle formation