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Topics: Cell, Cell membrane, Cell wall Pages: 2 (415 words) Published: December 5, 2013
active transport
requires chemical energy and usually a carrier protein, movement from low to high concentration (ex. sodium-potassium pump moves sodium ions to the outside of the cel and potassium ions to the inside) carrier protein

transports specific substances across the cell membrane
cell recognition protein
The process in which a cell recognizes or identifies its environment channel protein
forms channels for substances to move across a membrane
concentration gradient
a gradual change in the concentration of solutes in a solution as a function of distance through a solution. crenation
A process resulting from osmosis in which red blood cells, in a hypertonic solution, undergo shrinkage and acquire differentially permeable
some substances pass through freely while other do not-small uncharged molecules pass through the cell membrane following their concentration gradient diffusion
movement of molecules from area of high concentration to low concentration endocytosis
A process in which cell takes in materials from the outside by engulfing and fusing them with its plasma membrane. enzyme
catalyze chemical reactions for cell metabolism
exocytosis
moves molecules outside using a vesicle, requires energy (ex. release of insulin due to high blood glucose) facilitated diffusion
a carrier protein helps a bigger molecule carry out diffusion (passive transport) fluid-mosaic model
A model conceived by S.J. Singer and Garth Nicolson in 1972 to describe the structural features of biological membranes. glycoproteins
a protein covalently attached to a carbohydrate chain
hypertonic solution
causes cells to shrink; crenation in animal cells and plasmolysis in plant cells (more concentration) hypotonic solution
cause cells to swell and burst; lysis in animal cells, turgor pressure in plant cells (less concentration) isotonic solution
no change in cells
osmosis
diffusion of water across a semi-permeable membrane
osmotic pressure
force that cause water...
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