Movement across cell membranes Flashcards

2352280380	diffusion	The net movement of molecules or ions in a gas or liquid from an area of high concentration to an area where they are less concentrated.	0
2352280381	facilitated diffusion	The passive movement of molecules across membranes down their concentration gradient, which is aided by transport (carrier) protein molecules. No metabolic energy is required.	1
2352280382	osmosis	The movement of water molecules from a region of higher water potential to a region of lower water potential across a partially permeable membrane.	2
2352280383	active transport	Movement of substances across membranes against their concentration gradient, requiring the use of energy in the form of ATP. Active transport usually involves the use of transport proteins	3
2352280803	ATP	Adenosine triphosphate - a molecule used to store energy temporarily in organisms. The molecule is broken down to adenosine diphosphate + phosphate to release energy to drive metabolic processes.	4
2352280804	concentration gradient	The gradient in molecular concentration (the difference in concentrations) that allows diffusion to occur	5
2352281593	channel proteins	A protein pore that spans a membrane, through which very small ions and water soluble molecules may pass.	6
2352302461	carrier protein	A protein found in membranes, which is capable of carrying a specific molecule or ion through the membrane by active transport.	7
2352282768	water potential	A measure of the ability of water molecules to move freely in solution. Measures the potential for a solution to lose water - this is decreased by the presence of solutes.	8
2352283454	endocytosis	The process of taking materials into a cell by surrounding them with part of the plasma membrane, which then pinches off to form a vesicle inside the cell. This is an active process requiring ATP	9
2352283455	exocytosis	The process of removing materials from the cell by fusing vesicles containing the material with the plasma membrane (cell surface membrane).	10