Movement of substances pt. 2 Flashcards
simple + facilitated diffusion, active transport, osmosis
properties of substances that use simple diffusion?
small, non-polar, uncharged, hydrophobic
how does simple diffusion occur?
from a region of higher concentration to a region of lower concentration
what energy does simple diffusion use?
kinetic energy (no ATP needed)
properties of substances that use facilitated diffusion?
large, polar, charged, hydrophilic
the opposite of simple diffusion
how does facilitated diffusion occur?
from a region of higher concentration to a region of lower concentration
what energy does facilitated diffusion use?
kinetic energy (no ATP needed)
properties of substances that use active transport?
large, polar, charged, hydrophilic
same as facilitated diffusion
how does active transport occur?
from a region of lower concentration to a region of higher concentration
what energy does active transport use?
metabolic energy - adenosine triphosphate (ATP)
how does osmosis occur?
from a region of higher water potential to lower water potential (through a partially permeable membrane)
summary
simple diffusion
small, non-polar, uncharged, hydrophobic
higher to lower concentration
no ATP
facilitated diffusion
large, polar, charged, hydrophobic
higher to lower concentration
no ATP
active transport
large, polar, charged, hydrophobic
lower to higher concentration
ATP required
osmosis
higher to lower water potential
facilitated + simple diffusion
(only a small amount will go through by simple diffusion)
what is exocytosis?
it is the process by which cells export products such as enzymes by means of vesicles. (the substance is being transported out of the cell by vesicles)
the vesicles that were budded off from the Golgi apparatus will be guided to the cell surface membrane and then fuse with the membrane, discharging its contents to the outside of the cell.
what is endocytosis?
substances being imported into the cell.
fresh vesicles are formed at the cell surface. the cell surface membrane forms a ‘cup’ around a particle or a drop of fluid and encloses it to form a vesicle. the vesicle is then brought into the cytosol.
what is phagocytosis?
phagocytosis is endocytosis but it is only the wholesale import of solid matter.
what is pinocytosis?
it is endocytosis but only the bulk import of fluids
