3.5 active transport, endocytosis, and exocytosis

pumps

transport proteins that move materials against a concentration gradient

active transport

movement of a substance from a region of lower concentration to a region of higher concentration by the use of transport proteins embedded in the cell membrane and chemial energy

endocytosis

process of taking liquids or fairly large molecules into a cell by engulfing them in a membrane

cell membrane makes a pocket around a substance

pocket pinches together around the material and breaks off, forming a vesicle inside the cell

vesicle then joins with a lysosome, which breaks down the contents if needed and then recycles the vesicle

phagocytosis

type of endocytosis in which the cell membrane engulfs large particles

means cell eating

plays key role in immune system

white blood cells called macrophages find foreign material such as bacteria in your body and engulf and destroy them

exocytosis

opposite of endocytosis

release of substances out of a cell by the fusion of a vesicle with the membrane

vesicle forms around materials to be sent out of the cell vesicle then moves toward the cell’s surface, where it fuses with the memrane and lets go of its contents