Biology chap 4 vocab
Terms
undefined, object
copy deck
- passive transport
- movement across the cellmembrane that doesnt require energy from the cell
- concentration gradient
- a difference in teh concentration of a substance across a space
- equilibrium
- a condition in which the concentration fo substances is equal throughout space
- diffusion
- the movement of substanecs form an are of high concentration to an area of lower concentration caused by random motion of particles of the substance
- osmosis
- the diffion of water thorugh a selectively permaeable membrane
- hypertonic solution
-
lowers free water molecule concentration
cell shrinks
water out - hypotonic solution
-
higher free water molecule concentration
cell swells
water in - isotonic solution
-
same free water molecule concentration
cell stays same
in out at equal rate - ion channel
- transport protein with a polar pore through which ions can pass
- carrier protein
- a kind of transport protein that can bind toa specific substance on one side of the cell memebrane, carry the substance across the cell membrance and release it on the other side.
- faciliated diffusion
- when carrier proteins are used to transport specific substances such as amino acids and sugars down their concentration gradient.
- active transport
- the transport of a substance across the cell membrane against its concentration gradient
- sodium-potassium
- transports three sodium ions Na+, out the cell and two potassium ions, K+, into the cell
- endocytosis
- the movement of a substance into a cell by a vesicle
- exocytosis
- the movement of a substance by a cesicle to the outside of a cell
- receptor protein
- a protein that binds to a specific signal molecule, enabling the cell to respond tothe signal molecule
- second messenger
- acts asa a signal moleculee in the cytoplasm. amplifies the signal of the first messenger