methods + types of transport Flashcards
methods of transportation
- use a transport protein -> large, charged, or going against gradient (may be passive or active)
- through the phospholipid bilayer -> small /or no charge
glucose (C6H12O6)
protein - too large to go through the bilayer, would get stuck.
amino acid
protein - too large to go through bilayer, would get stuck.
O2
bilayer - small (can fit) + no charge (not repelled by non-polar fatty acid tails)
CO2
bilayer - small (can fit) + no charge (not repelled by non-polar fatty acid tails)
H2O
protein (aquaporin) - polar + would get repelled by non-polar fatty acid tails
Na+
protein - charged (cation), would be repelled by non-polar fatty acid tails
K+
protein - charged (cation), would be repelled by non-polar fatty acid tails
passive transport
- doesn’t use ATP (energy)
- high -> low concentration
- goes along with natural concentration gradient
simple diffusion
any movement from H -> L concentration without using a transport protein.
ex. cookie smell diffuses throughout house, O2 going into a cell
PASSIVE
facilitated diffusion
using a transport protein to move a substance from H -> L concentration.
ex. glucose + amino acids coming into a cell (too large)
PASSIVE
osmosis
the movement of H2O from a H -> L concentration.
PASSIVE
hypertonic
(adj.) cell or solution has LESS H2O in comparison
hypotonic
(adj.) cell or solution has MORE H2O in comparison
isotonic
(adj.) cell and solution have reached dynamic equilibrium in H2O concentration. molecules will continue to move, but no net change will occur.
water will move…
from HIGH to LOW concentration
- or -
from HYPOtonic to HYPERtonic
plant cells
turgor pressure - cell is hypertonic, receives H2O, membrane expands and pushes up against cell wall
plasmolysis - cell is hypotonic, solution/other substance hypertonic. water leaves cell, cell dehydration + wilting.
active transport
- uses ATP (energy)
- low -> high concentration
- goes against concentration gradient
transport protein
Na+/K+ pump: protein has a spot where ATP (adenosine triphosphate) can attach itself. this powers the opening and closing of bringing the ions into and out of the cell.
K+ low outside cell, high inside cell (coming inside cell)
Na+ low inside cell, high outside cell (going out of cell)
endocytosis
cell engulfs large substances
phagocytosis: substance being engulfed is a solid
pinocytosis: substance being engulfed is a liquid
ex. white blood cell engulfing viruses
ACTIVE
exocytosis
a cytoplasmic vesicle fuses w/ cell membrane and its contents are released outside cell
ex. products from golgi being released into bloodstream
Brownian Motion
FACTORS AFFECTING DIFFUSION:
constant random motion of molecules unless at absolute 0
dynamic equilibrium
FACTORS AFFECTING DIFFUSION:
molecules will continue to move until equal - no net change of movement after equilibrium has been reached
substances diffuse independently of each other
FACTORS AFFECTING DIFFUSION:
look at each molecule by itself, one molecule will not diffuse at the same rate as the other necessarily
steeper concentration gradient
FACTORS AFFECTING DIFFUSION:
steeper = faster diffusion, more fervency to reach equilibrium as variation is so high
molecular size
FACTORS AFFECTING DIFFUSION:
smaller = faster diffusion as it is easier for them to move through membrane
temperature
FACTORS AFFECTING DIFFUSION:
higher temp = faster diffusion as heat makes molecules move faster
molecules always move down gradient
FACTORS AFFECTING DIFFUSION:
this requires no energy, anything moving from L -> H requires ATP.
