Phosophlipids
Phospholipids will form a bilayer when placed in water.Phospholipid bilayers are fluid.
Membrane StructureCellular membranes have 7 different components:1. Phospholipid bilayer2. Transmembrane protein3. Interior protein network
Membrane StructureCellular membranes have 7 different components:4. Cell surface markers5. Protein pumps6. Cholesterol7. Receptor proteins
Diffusion - Passive Transport“Movement of a molecule across a membrane without the use of energy”
Diffusion is a form of passive transport.
Facilitated DiffusionFacilitated diffusion: “Molecules that cannot cross the membrane easily alone can do so with the help of specific proteins”
Cells in SolutionIsotonic
• “The concentration of water and dissolved solutes is the same on the inside of the cell and in the solution outside”.
Cells in SolutionHypotonic
• “The concentration of dissolved solutes is lower (and the concentration of water is higher) in the solution than in the cell.
Cells in SolutionHypertonic
• “The concentration of dissolved solutes is higher (and the concentration of water is lower) in the solution than in the cell.
Bulk Transport - Endocytosis• The cell
membrane forms a vessicle by surrounding a large molecule or group of molecules.
• The vessicle brings the molecule(s) into the cell.