Cell Transport Vocab

cell membrane

selective permeable membrane that controls what enters and leave the cell

Active Transport

movement of particles against concentration using ATP

passive transport

movement of particles along concentration gradient without the use of energy

Diffusion

movement of particles from low to high concentration

osmosis

movement of water molecules from high to low concentration across a membrane

endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

exocytosis

Process by which a cell releases large amounts of material

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells

Homeostasis

process by which organisms maintain a relatively stable internal environment

Pinocytosis

A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.

Effectors

muscles or glands that cause responses that alter conditions in the internal environment

Receptors

Special structures that allow living organisms to sense the conditions of their internal or external environment.

Stimulus

A change in an organism's surroundings that causes the organism to react

hypotonic solution

A solution in which the concentration of solutes is less than that of the cell that resides in the solution

hypertonic solution

A solution in which the concentration of solutes is greater than that of the cell that resides in the solution

isotonic solution

A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution

negative feedback

a mechanism of response in which a stimulus initiates reactions that reduce the stimulus

positive feedback

Feedback that tends to magnify a process or increase its output.

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels

Concentration Gradient

A difference in the concentration of a substance across a distance.