A thin, flexible barrier around a cell; regulates what enters and leaves the cell
Structure of Membrane
-two layers of phospholipid molecules on both side polar phosphate head (hydrophillic) and non-polar fatty acid tail (hydrophobic)
Plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and nonpolar tails facing the inside.
(the ability to allow some sub. to cross the plasma membrane more easily) A property of biological membranes that allows some substances to cross more easily than others.
No additional energy input is reqd movement into and out of cells the net movement of water molecules through a selectively permeable membrane from an area of higher water concentration (low solutes) to low water concentration (high solutes) is osmosis LOW TO HIGH
Process of membrane transport that has movement of a substance up concentration gradient HIGH TO LOW
Movement of molecules from an area of higher concentration to an area of lower concentration. Both osmosis and faciliated diffusion are a type of this
Exchange of both oxygen and carbon dioxide through the respiratory membrane occurs by the movement of particles from a higher concentration to a lower concentration nonpolar and lipid-soluble substances diffuse directly through the lipid bilayer. unassisted movement to equalize
typically across capillary walls uses integral membranes moves large charged hydrophobic cells
Diffusion of water across a selectively permeable membrane Diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal.
Pressure exerted by a volume of fluid against a wall, membrane, or some other structure that encloses the fluid.
pressure that must be applied to prevent osmotic movement across a selectively permeable membrane
Total concentration of solute particles in a solution
ability of a solution to alter a cells water volume
concentration outside the red blood cell equals the concentration inside the red blood cell. equal to cytosol
Solution with higher concentration than cytosol
Solution with lower concentration than cytosol
water attracted this term literally mens "water loving"; it refers to substances that are made of polar molecules like water
water fearing Having an aversion to water; tending to coalesce and form droplets in water.
The movement of a substance across a membane via pressure. .
Transport of large particles and macromolecules across plasma membranes
allows movement of the two between the cellmembranes Active transport (uses ATP) to move 3 Na (in) and 2 K (out) against their concentration gradient
A process in which a cell engulfs extracellular material through an inward folding of its plasma membrane.
Food particles are engulfed and ingested by the cell
A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.
Process by which a cell releases large amounts of material
Molecule with partial charges. Mixes with water. 2 sides