Phys Flashcards
Cell membrane structure
Phospholipid bilayer, proteins
Membrane proteins
Peripheral and integral (depending on function)
Membrane transport types
Passive, Active (Primary or Secondary), and vesicular traffic
Simple diffusion (passive)
No energy is required, movement of molecules either directly through the bilayer or through channels
Gated channels
Voltage gated, Ligand gated
Factors affecting rate of simple diffusion
Concentration gradient, Surface area of membrane, solubility in the membrane (permeability), thickness of the membrane, molecular weight of diffusing particle.
Facilitated diffusion
Protein is required for transport
Active Transport
Movement against a concentration gradient, requires ATP
Primary Active transport
Single protien
Secondary active transport
2 proteins in tandem (energy generated by 1 protein and used by another)
Rate of transport (protein mediated)
More than it would be by diffusion
Saturation kinetics
Rate increases as saturation increases
Chemical specificity
Ligand-specificity
Competition
Similar chemicals compete for same carrier protein
Endocytosos
Macromolecules invaginate into the cell
