Pack 3

MEMBRANE = CONTROLS PASSAGE OF MOLECULES IN AND OUT OF A CELL OR ORGANELLE, ITS COMPONENTS CONSIST OF:

PHOSPHOLIPIDS = HYDROPHILIC HEAD HYDROPHOBIC TAIL FORM PHOSHOLIPID BILAYER, ALLOW MOVEMENT OF LIPID-SOLUBLE SUBSTANCES BUT NOT WATER-SOLUBLE

PROTEINS = EXTRINSIC PROTEINS ACT AS CELL SURFACE RECEPTORS, INTRINSIC ACT AS CHANNEL OR CARRIER PROTEINS TO ALLOW MOVEMENT OF WATER-SOLUBLE MOLECULES, PROVIDE STRUCTURAL SUPPORT, HELP CELLS STICK TOGETHER, ALLOW ACTIVE TRANSPORT DIFFUSION AND OSMOSIS

CHOLESTEROL = HYDROPHOBIC SO PREVENT WATER LOSS FROM CELLS, PROVIDE STRENGTH TO MEMBRANE, MAKE IT LESS FLUID AT HIGH TEMP

GLYCOLIPIDS = LIPID COVALENTLY BONDED TO CARBOHYDRATE, ACT AS RECOGNITION SITES AS CELL SURFACE RECEPTORS, HELP CELLS ATTACH TO FORM TISSUES

GLYCOPROTEIN = CARBOHYDRATE ATTACHED TO EXTRINSIC PROTEINS, ACT AS RECOGNITION SITES, HELP CELLS ATTACH TO EACHOTHER TO FORM TISSUES

PERMEABILITY = MOLECULES CAN'T FREELY DIFFUSE THROUGH IF NOT LIPID SOLUBLE OR IF TOO BIG FOR PROTEIN CHANNELS, OR IF SAME CHARGE AS PROTEIN CHANNELS SO GET REPELLED

FLUID-MOSAIC MODEL = FLUID BECAUSE MOLECULES MOVE RELATIVE TO EACHOTHER ALLOWING FLEXABILITY, MOSAIC BECAUSE PROTEINS EMBEDDED IN BILAYER VARY IN SIZE AND SHAPE LIKE A MOSAIC

DIFFUSION = PASSIVE MOVEMENT OF MOLECULES FROM AN AREA OF HIGH CONCENTRATION TO LOW CONCENTRATION DOWN A CONCENTRATION GRADIENT UNTIL EQUILIBRIUM REACHED

FACILITATED DIFFUSION = OCCURS AT SPECIFIC POINTS ON THE MEMBRANE INVOLVING CARRIER AND CHANNEL PROTEINS THAT ALLOW SPECIFIC IONS THROUGH THE MEMBRANE, MOLECULE BINDS TO PROTEIN MAKING IT CHANGE SHAPE AND PASS IT THROUGH THE MEMBRANE, NO ATP REQUIRED

OSMOSIS = THE MOVEMENT OF WATER FROM AN AREA OF HIGH WATER POTENTIAL TO LOW WATER POTENTIAL, OCCURS DUE TO KINETI ENERGY OF MOLECULES THROUGH A SELECTIVELY PERMEABLE MEMBRANE ALLOWING WATER THROUGH NOT SOLUTE, UNTIL DYNAMIC EQUILIBRIUM IS REACHED

SOLUTE = SUBSTANCE DISSOLVED IN A SOLVENT TO FORM SOLUTION

WATER POTENTIAL = MEASURED IN KPa, CREATED BY PRESSURE OF WATER MOLECULES UNDER STANDARD PRESSURE AND TEMP CONDITIONS, ADDING SOLUTE LOWERS WP, MORE CONCENTRATED LOWER WP

PLANT CELLS = CAN BE TURGID (STRETCHED) PLASMOLYSED (SHRIVELED) AND INCIPIENT PLASMOLYSED (IN BETWEEN) 

ACTIVE TRANSPORT = SELECTIVE MOVEMENT OF MOLECULES ACROSS A MEMBRANE FROM AN AREA OF LOW CONCENTRATION TO HIGH CONCENTRATION AGAINST A CONCENTRATION GRADIENT USING ATP AND CARRIER PROTEINS

CARRIER PROTEINS = CARRIER BINDS TO MOLECULE USING RECEPTOR SITES, ATP BINDS TO CARRIER CHANGING ITS SHAPE RELEASING MOLECULE ON OTHER SIDE OF MEMBRANE, PHOSPHATE RELEASED CARRIER CHANGES SHAPE BACK

SODIUM-POTASSIUM PUMP = NA+ BINDS TO SPECIFIC RECEPTOR ON CARRIER, ATP BINDS TO CARRIER, ATP SPLITS TO ADP AND Pi, ENERGY RELEASED, CARRIER CHANGES SHAPE RELEASING NA+ ON OTHER SIDE, SAME HAPPENS ON OTHER SIDE FOR K+

EPITHELIAL CELLS = HABE MICROVILLI FOR MORE SURFACE AREA FOR DIFFUSION AND ACTIVE TRANSPORT

CO-TRANSPORT = NA+ OUT OF CELL BY ACTIVE TRANSPORT IN SODIUM POTASSIUM PUMP, MAINTIANING HIGH CONC OF NA+ IN LUMEN, NA+DIFFUSES BACK IN CARRYING GLUCOSE WITH IT USING A CO-TRANSPORT PROTEIN, GLUCOSE THEN PASSES INTO THE BLOOD BY FACILITATED DIFFUSION