drydecay-
What three factors affect the permeability of a cell membrane (and tonoplast)
Heat, Ph and ethanol
-
What happens when the temperature is too high
Proteins in the membrane denature
-
What happens when the Ph levels are beyond the normal range
Proteins in the membrane denature
-
What happens when exposed to ethanol
Lipid components of the membrane dissolve
-
Diffusion
Movement of a molecule or ion down a concentration gradient from a high concentration to a low concentration
-
What type of process is diffusion
Passive
-
Factors that effect the rate of diffusion
Concentration gradient, Membrane thickness, particle size and type (fat diffuses faster than water soluble)
-
Protein channel
Pores are hydrophilic allowing ions to pass through (sodium). Open and close depending on the needs of the cell. Can be called gated
-
Carrier protein
Large polar molecules through (sugars, amino acids) Molecule attaches to binding site, changes shape/rotates. It then releases the molecule on the other side of the membrane
-
Facilitated diffusion
Special form of diffusion that allows the movement of molecules or ions across a membrane
-
What type of process is Facilitated diffusion
Passive process
-
Where does Facilitated diffusion occur
Specific site on the cell membrane where there is a transport protein molecule
-
Active transport
Movement of particles from an area of low concentration to an area of higher concentration, against the concentration gradient across a cell membrane. Uses ATP and protein carriers
-
Why is active transport important
Reabsorption in kidneys, absorption in small intestine, uptake of inorganic ions in plants and nerve transmission
