Week 2: Membrane Transport Flashcards
Phospholipids in cell membrane
Principal component
Bi-layer arrangement
Hydrophilic phosphate head
Hydrophobic fatty acid tail
Membrane flexibility and fluidity (movement, saturation, cholesterol)
Phospholipids constantly switching spots laterally.
Unsaturated (gaps) vs saturated (tightly packed)
Cholesterol (stabilizes membrane by wedging between gaps or pushing heads apart)
Integral Proteins
Glycolipid
Lipid with carb attached
***
Glycolyx
Sugar coating on membrane
Cell recognition
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Which passes easily through membrane?
Small and non-polar.
Passive Transport
Diffusion, Osmosis, Facilitated Diffusion
Active Transport
Active
Transport Vesicles:
Endocytosis: Phagocytosis, Pinocytosis, Exocytosis
Solution
Solvent and solute
Solvent
Medium that the solutes dissolves in
Solute
Substance dissolved in the solvent
Concentration Gradient
More solute in one part of a solvent than another.
Movement from high to low concentration
Diffusion
Movement from high concentration to low concentration until equilibrium is reached.
Small, hydrophobic, uncharged particles.
Facilitated Diffusion
Diffusion of a substance across membrane with aid of transport proteins.
Integral Proteins
Channel and carrier
Channel Proteins
Open all the time
Small, polar molecules can pass
Specific channels for each molecule
Some have gates
Carrier Proteins
Binds to substance, releases on the other side.
Osmosis
Type of facilitated diffusion.
Movement of water from area of high concentration to low water concentration.
Function of Osmosis
Maintaining proper pressure within cells.
Hypotonic
Lower solute concentration than another solution.
Lysed cell.
Hypertonic
Higher solute concentration than another solution.
Shriveled cell.
Isotonic
Equal concentration to another solution..
Active Transport
Movement of substance against concentration gradient.
Function of Active Transport
Cell can gain needed nutrients that are at different concentration levels inside the cell vs outside.
Phagocytosis
Active transport.
Cell takes in large materials by engulfing it within the membrane.
Vesicle formed, digested by lysosome.
Pinocytosis
OR Endocytosis.
Small molecules or droplets of fluid taken up by cell.
Exocytosis
Vesicles fuse with cell membrane to release materials into extracellular fluid.