transport in cells Flashcards
why to cells need to transport substances
waste products
products for respiration
what do cells need for cellular respiration
chemicals like glucose and oxygen
role of cell surface membrane
controlles transport of materials in and out of the cell
glycoproteins
act as antigens
important for cell recognition
receptors for hormones
neurotransmitters
reactions with a cell/ cascade
peripheral proteins
may be enzymes
involved in regulating transport
cell signalling
membrane bi layer
polar heads inside and outside with hydrophobic lipid core
layer contains integral proteins
hydrophillic part of bi layer
pore
hydrophillic channel
integral proteins
main transportation
form either stable pores or other transport mechanisms like carrier proteins or active pumps
what do glysoproteins have attached to them
carb chains
passive transport
takes place as a result of concentration
pressure
electrochemical gradients
no energy
diffusion
movement of particles in a liquid or gas down conc gradient.
high to low conc
what effects transportation of molecules
properties of the membrane
size of molecule
solubility in lipids and water
charge of molecule
what types of substances can move easily past membrane
oxygen
carbon dioxide
molecules that cant diffuse across membrane
steroid hormones
charged particles
order of movement in diffusion
they move down conc gradient because of random movement of molecules due to temp
whats uniform distribution
when you have large packed molecules they will move spreading out until spread out
movement after equilibrium reached
after standard reached the molecules move but the movement doesnt cause a net change in conc because equal numbers are moving in all directions
what does facilitated diffusion include
proteins in the membrane that allow only specific substances to move through passively down their conc gradient
process of channel proteins in facilitated diffusion
molecules to be transported
-move into protein carrier of specific shape
-protein changed shape and molecule passed through
-protein carrier returns to original shape
gated channels
only open when a specific molecule is present or there is an electrical change across membrane
