2.3 Permeability and Transport Flashcards
(20 cards)
Selective Permeability
Cell membrane allows certain materials to cross but other need help
Hydrophobic (nonpolar) molecules
Dissolve in Bilayer and cross easily
Hydrophilic molecules
Cannot pass through
Get help from Proteins
Transportation Proteins
allow hydrophilic substances to cross membrane
Channel Protiens
Hydrophilic channel that molecules use as a tunnel
Aquaporins
Channel proteins = allow water molecules to pass
Passive Transport
Does not require ATP to move molecules across the membrane
- High to Low Concentration
Active Transport
Requires ATP to move molecules across membrane
- Low to High Concentration
Diffusion
Type of passive transport
- With the concentration gradient; High to Low
Move in a certain direction to reach equilibrium
Facilitated Diffusion
Move High to Low and use Protein
Channel Proteins
provide opening inside and outside cell
Carrier Proteins
Bind to the molecule/help it move
Aquaporins
Allow water to pass through (Carrier proteins)
Ion Channels
Ion Channels have grates that open or close due to the environment
Primary Active Transport
-Cells use ATP directly
-All of proteins in active transport are carrier proteins
Sodium/Potassium pumps
Move sodium or potassium from low to high concentration
- Na+ goes from inside to outside
-K+ goes from outside to inside
Secondary Active Transport
-Cells use ATP indirectly
- Uses the energy from the primary transport gradient
-Glucose goes in with Na+
Endocytosis VS Exocitosis
Endo = moves substances into the cell via vesicles
Exo = moves substances outside of a cell via vesicles
Pinocytosis/Phagocytosis
Pino = cell membrane breaks to bring water in
Phag = Membrane surround sm or another cell to being in materials
Receptor-mediated Endocytosis
Cells take in molecules by binding them to the receptor proteins — This binding causes vesicle formation = The vesicle will then release the molecule into the cell
