22 terms

A&P Lab Five

movement of solute molecules from an area of greater concentration to an area of lesser concentration
a solution surrounding a cell is hypertonic is
it contains more nonpenetrating solute particles than the interior of the cell
passive processes
pressure differences drive the movement
active processes
ATP powers transport
occurs only across capillary walls
all molecules
possess energy and are in constant motion
molecules diffuse passively if
can dissolve in lipid portion of membrane
simple diffusion
unassisted diffusion of solutes through a differentially permeable membrane
facilitated diffusion
(passive) molecules transported with assistance of protein carrier molecules, small ions cross membrane by moving through water-filled protein channels
flow of water across differentially permeable membrane; concentration of water is inversely related to the concentration of the solutes, cause changes in the volume of the compartments on either side of the membrane
contains more nonpenetrating solute particles than the interior of the cell; water moves down concentration gradient
contains fewer solute particles than interior of the cell; water moves down concentration gradient
cells burst as the water floods into them, leavings "ghosts"
active transport
requires carrier proteins; primarily driven by ATP or secondary driven by energy store; substances move against concentration gradient; some are amino acids and some sugars
sodium ions are ejected from the cell by this
vesicular transport
large particles and molecules transported across membrane
membranous sac thus formed, phagosome, fused w/ lysosome and contents digested; mainly found among white blood cells and macrophages to help protect body from disease and cancer cells
molecular motion
-reflects the kinetic energy of molecules
-is random and erratic
velocity of molecular movement
-is lower in larger molecules
-increases with increasing temperature
-reflects kinetic energy
what single characteristic of the differentially permeable membranes in lab determine the substances that can pass through them
size of pores in dialysis sac
what other factors influence passage of substances through living membranes
size of molecules, polarity of molecules, concentration gradient
characterize passive processes
-include osmosis, simple diffusion, and filtration
-use hydrostatic pressure or molecular energy as the driving force
-account for the movement of fats and respiratory gases through the plasma membrane
characterize active processes
-may occur against concentration and/or electrical gradients
-explain solute pumping, phagocytosis, and pinocytosis
-move ions, amino acids, and some sugar across the plasma membranex