Transport Across the Plasma Membrane Class Notes Flashcards
What are the two ways substances corss the mebrane
Passive Process-no energy is required to get substances across the membrane
Active Process-energy(ATP) is required to get substances across the membrane
what is Simple Diffusion
if the molecule passes right through the plasma membrane
Facillitated diffusion
when the molecule uses a protein carrier or channel to get through the membrane-Amino acids, sugars, and ions move THROUGH the membrane this way
HINT: think of proteins as the fascilites in the plasma membrane
Osmosis
Diffusion of water through the plasma membrane, pictured below
COncentration gradient
degree of concentration within around a cell
What 2 factors affect the rate of diffusion
size and temperature
What are carriers?
integral proteins that transport specific polar molecules that are too large to squeeze through channels. For ex. glucose carriers only carry glucose. When the molecule binds to the protein, the protein changes shape, moving the molecule in the process
what are channels?
integral proteins that have an opening or pore that has a fluid filled core(mostly water) that moves materials such as cations, anions and water down the concentration gradient.
What are water channels called
aquaporins
list the 2 types of channels
Leakage channels- Always open
Gated Channels- Controlled by chem. or electrical signals
Tonicity
amount of SOLUTION to change the shape or tone of cells by altering the cells’ internal water volume
what is it called when a cell bursts
lyse
name hte 2 mahor active membrane transport process
actie transport and vesicular transport
Both active and vesicular transport require what
ATP, for any of these reasons:
solute too large for channels
solute is not lipid soluable
solute is not able to move down concentration gradient
active and vesicular requires what type of protein
carrier proteins
