what is the name for the double layered sheet structure that makes up the cell membrane?
lipid bilayer
The control of particle movement across a membrane
Seletive permeability
What is the reason that oxygen can pass freely through a membrane but sodium requires effort?
the membrane is selectively permeable
Why is it called a Membrane Mosiac Model?
Many molecules make up the structure of the membrane that it is called a "mosiac"
Proteins that are permanently connected to the membrane and go from one side to the other..
Integral Proteins
Proteins that allow ions to pass through the membrane down their concentration gradient
Channel proteins
Proteins that change their shape to help facilitate diffusion down their concentration gradient
Transport Proteins
These proteins are not bonded strongly to the membrane and may attach to an integral protein or just sit on the surface
Peripheral Proteins
Protiens that act like a "flag" and give other cells information about the cell. Have a polysaccharide tail sticking out of the membrane.
Glycoproteins
Three types of Passive Transport?
1) diffusion
2) osmosis
3) facilitated diffusion
what is the difference in concentration called between a region of high concentration and a region of lower concentration?
concentration gradient
when the concentrationi of the solute is the same throughout the system
equilibrium
passive transport is the movement of molecules across a membrane ___________ the concentration gradient
with or down. from high to low concentration
the movement of particles from an area of high concentration to lower concentration
diffusion
true or false: diffusion requires energy to work
false
True or false: at equilibrium the molecules stop moving and stay on that side of the membrane
false, molecules are always moving, but the net change is equal
The diffusion of water across a selectively permeable membrane
osmosis
Why does the water rise on one side of the membrane?
the particles can't cross the membrane making the water move over in order to try and reach equilibrium
both sides of a membrane have equal concentrations, equilibrium has been reached
isotonic
word used to describe a higher solute concentration
hypertonic
word used to describe a lower solute concentration
hypotonic
label what type of solution is causing the change in the red blood cells (remember their "normal" concave shape) either isotonic, hypertonic or hypotonic
isotonic, hypotonic, hypertonic
true or false: osmosis requires energy
false
true or false: osmosis is not dependent on concentration gradients
false, all forms of passive transport move molecules (even water molecules) with the concentration gradient
movement of molecules across a membrane using protein channels
facilitated diffusion
true or false: facilitated diffusion requires energy
false
true or false: active transport requires energy
true
active transport moves molecules ____________ the concentration gradient, requiring energy
against
process by which a cell engulfs molecules
endocytosis
type of endocytosis, when the cell engulfs liquid
pinocytosis
type of endocytosis, engulf particles including bacteria or other cells
phagocytosis
the process in which a cell excretes a vesicle, form of active transport
exocytosis
type of protein needed for active transport across the membrane, ATP is used to "change the shape"