Transport : diffusion osmosis + active transport Flashcards
Diffusion
a net movement of particles through a partially permeable membrane from an area of higher concentration to an area of lower concentration
Diffusion must occur within
a gas / dissolved substance
Net movement
movement of all particles
when molecules are left alone..
they move randomly
diffusion is a __________ process
because it doesn’t require…
passive
energy from the cell, it is random movement of molecules
partially permeable
only lets through smaller molecules such as water
3 factors that affect the rate of diffusion
concentration gradient
temperature
surface area
how does the concentration gradient affect diffusion
larger concentration gradient + higher rate of diffusion)
how does temperature affect diffusion
higher temperature gives particles more energy to move faster
higher temp –> high rate of diffusion
how does surface area affect diffusion
large surface area = more particles can fit around surface
large surface area –> higher rate of diffusion
osmosis
the net movement of water molecules through a partially permeable membrane from an area of higher water concentration to an area of lower water concentration
water concentration
amount of water compared to other molecules , like sugars and salts, dissolved in water
hypotonic
lower concentration of solutes than inside the cell
hypertonic
higher concentration of solutes than inside the cell
isotonic
concentration of solutes is equal inside and outside cell