4.1 Flashcards
what organelles are involved in transport
rough ER
golgi aparatus
nucleus
glycoproteins
act as antigens
cell recognition
receptors for hormones
peripheral proteins
can be enzymes
can be involved in regulating transport
ingtegral proteins
main transport system of the membrane
can be permenant pores or other transport mechanisms e.g. carrier proteins or active pumps
passive transport e.g’s
diffusion
facillitated diffusion
osmosis
diffusion
movement of particles down the concentration gradient
high concentration to low concentration
cell membranes are no barrier
small particles/ non polar
lipid soluble
- oxygen
-carbon dioxide
facillitated diffusion
diffusion through carrier/channel proteins
protein lined pores of the cell membrane
charged molecules
water soluble
osmosis
specialist form of diffusion
high water potential to a low water potential
through a partially permeable membrane
active transport e.g’s
endocytosis
exocytosis
active transport
moved across membrane by carrier proteins
needs atp
endocytosis
movement of large molecules into cells through vesicle formation
fluid nature allows formation
exocytosis
movement of large molecules out of cells through vesicle formation
Active Transport definition
movement of molecules from low to high concentration against the concentration gradient using carrier proteins - energy required
isotonic solution
the osmotic concentration of the solutes in the solution is the same of that in the cells
hypotonic solution
the osmotic concentration of the solutes in the solution is lower of that in the cytoplasm of the cells
water into cells
turgid
hypertonic solution
the osmotic concentration of the solutes in the solution is higher than in the cytoplasm
water out of cells
plasmoylsed
osmotic potential
potential of water to move across a partially permeable membrane from a hypotonic to hypertonic
turgor pressure
pressure generated on the swelling protoplasm pushes against the cell wall
when put in distilled water it will increase
water potential
turgor pressure + osmotic potential(-)
lowest wp is most conc
osmosis in the form of water potential
net movement of water molecules from an area of less negative water potential to an area of more negative water potential through a partially permeable membrane
active transport
use a carrier protein
energy supplied by atp
against concentration gradient
one way system
as oxygen conc increases rate of uptake increases
carrier proteins in active transport
can be speicific only picking up one type of ion or molecule
or can work for many small ions that have to compete with each other
break down of fibrous proteins
hydrolsis reaction to form amino acids
increase in temp on membrane permeability
as temperature inreases permeability increases
due to the movements of phospholipids
at higher temps proteins begin to denature and more can escape
ethanol
ethanol damages phospholipids membrane becomes more permeable
importance of phospholipids
polar phosphate head reacts with aqueous enviroment
polar particles cant pass through the nonpolar tails so go through carrier proteins
changes in water potential
water enters the cell by osmosis
water potential of solution higher than cell
turgor pressure increases
so water potential = 0 until turgor pressure = 0
as cell wall prevents further entry of water
