CELL MEMBRANE
TRANSPORT
TYPES
Simple diffussion
Diffusion from an area of higher concentration to a lower one
What can move?
hydrophobic and lipophilic nature, of small size and without electric charge.
Osmosis
only happen if the phospholipid bilayer is permeable to the particles.
movement
Facilitated diffusion
Water is able to move
Active transport
FLUIDITY
Vesicles
Endocytosis
Exocytosis
ATP energy required
property
allows material to move inside the cell
due to
phospholipids
no energy used
concentration gradient
Difference in concentration of a substance on two sides of a membrane.
channels
small sac of membrane
present in eukaryotic cells
moves materials around inside cells
allows materials in vesicles to be taken inside cells be endocytosis.
holes with a very narrow diameter.
Water molecules pass through a membrane
for this
proteins pull a small section of the membrane, using ATP.
Channels for particles to pass
Free movement through specific channels.
Doesn't need energy
examples
vesicles contain water, solutes but also larger molecules
vesicles
can release materials from cells
if
vesicle fuses with plasma membrane
contents are released of the membrane
can also
expel waste products
from a higher to a lower concentration
only one type of particle passes (not both)
glucose transport and ion transport (can't pass because of its charge and polarity)
No energy required
due to
concentration gradient
in
substances dissolved in water
Types
Isotonic
Hypertonic
Hypotonic
same number of
dissolved particles
than
higher
concentration of
dissolved particles
than
lower
number of dissolved
particles
than
the cell cytoplasm
Cell sometimes take in substances, it is absorbed against the concentration gradient.
by
proteins in membranes (pump proteins)