Unit 3 Flashcards
what is diffusion
the net movement of particles from a region of higher concentration to a region of lower concentration down a concentration gradient as a result of their random movement
where does the energy for diffusion come from
it comes from the kinetic energy of the molecules
what is the rate of diffusion affected by
surface area
temperature
concentration gradient
distance
what is osmosis
the net movement of water from an area of high water potential to low water potential through a partially permeable membrane
what are dilute solutions
they have little dissolved solute in them and has low concentration
what are concentrated solutions
have lots of dissolved solute in them
why is water able to diffuse through partially permeable membrane
due to osmosis
what is water potential
measures how freely water can move around
what happens if the concentration of a solution increases
its water potential decreases
what is osmosis in terms of solutions
the net movement of water molecules from a dilute solution to a concentrated solution through a partially permeable membrane
what happens when plant cells absorb water
they become turgid
swollen due to high water content and become stiff
what happens when plant cells lose water
the cytoplasm and vacoule shrink decreasing the pressure and the cell becomes less stiff
they become flaccid
what is plasmolysis
when the cytoplasm pulls away from the cell wall and the cell usually dies
what is active transport
the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration
goes against the concentration gradient
how is active transport possible
through carrier proteins
they are embedded in the cell membrane and allow passage through it
