CHAPTER 3 - vocabulary terms (membrane transport)

Filtration

Movement of molecules through a selectively permeable as a result of hydrostatic pressure; form of passive transport

Simple diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration until an equilibrium is reached; form of passive transport

Osmosis

The diffusion of water through a selectively permeable membrane; water moves from an area of higher water (lower solute) concentration to an area of lower water (higher solute) concentration; form of passive transport

Facilitated diffusion

Transport of molecules through a selectively permeable membrane, down their concentration gradient, by a carrier protein that does not require ATP; form of passive transport

Primary active transport

Transport of particles through a selectively permeable membrane by a carrier that uses ATP; particles move up their concentration gradient

Secondary active transport

Transport of particles through a selectively permeable membrane by a carrier that does not use ATP itself but depends on a concentration gradient produced by primary active transport

Endocytosis

Vesicular transport of particles into the cell

Phagocytosis

Form of vesicular transport by which large particles are brought into the cell; "cell eating"

Pinocytosis

Form of vesicular transport by which particles dissolved in extracellular fluid are brought into the cell; "cell drinking"

Receptor-mediated endocytosis

Pinocytosis or phagocytosis in which specific molecules bind to receptors on the plasma membrane, and are then taken into the cell in clathrin-coated vesicles

Gradient

A difference in chemical concentration, electrical charge, physical pressure, or temperature between one point and another

Exocytosis

Form of vesicular transport in which materials are eliminated from a cell by means of a vesicle fusing with the cell membrane and expelling its contents

Transcytosis

Vesicles undergo endocytosis on one side of cell, move across cell, and then undergo exocytosis on opposite side.