diffusion osmosis active transport Flashcards
diffusion
movement of molecules of a solid liquid gas from an area where they are in higher concentration to an area where they are in a lower concentration
particles move down a concentration gradient
no energy required passive process
particles continue to move until equilibrium is reached at which point no net movement of particles in any one direction
examples of diffusion
smelling perfume across a room
drop of food colouring making whole bowl of water change colour
movement of oxygen gas across alveoli into blood capillaries
define osmosis
movement of water molecules from an area of higher concentration to an area where they are in a lower concentration across a selectively permeable membrane
movement of water from an area of high water potential to an area of lower potential across a partially permeable membrane
movement of water from a hypotonic to a hypertonic solution across a partially permeable membrane
3 examples of osmosis
feeling thirsty after having salty food
salt on slugs
water uptake by plant roots
define water potential
tendency of water to move out of a system
what water potential is pure water
0 - highest water potential
any other solution has a negative water potential meaning more solutes prevent in a solution more lower water negative
define isotonic
equal concentration of solutes and solvents
define hypotonic
fewer solutes more solvent
define hypertonic
more solutes less solvent
define plasmolysis
process whereby cell membrane in plant cell pulls away from cell walls
cytoplasm and vacuole shrink
space between cell wall and cell membrane filled with external solution
define active transport
movement of molecules from an area where they are in lower concentration to an area where they are in higher
molecules move against their concentration gradient
requires energy active process
list 2 examples of active transport
mineral ions move into plant roots
uptake of glucose by epithelial cells in villi
