Phospholipid Bilayer Polar Head Nonpolar Tail

Phospholipids Red Region = Glycerol Weak Hydrogen Bonds

Fluid Mosaic Membrane

Glycoproteins These proteins are found on the surface of all of your body cells. They are genetically determined and unique to each person. They allow our body to know self from non-self.

Cholesterol  Makes up to 50% of membrane  Cholesterol, like phospholipids is also hydrophilic and hydrophobic. Cholesterol helps prevent extremes-- whether too fluid, or too firm-in the consistency of the membrane  Slightly immobilize the outer surface of the membrane and make it less soluble to very small water-soluble molecules.  Literally helps to keep the membrane from crystalizing  Makes up to 50% of membrane  Cholesterol, like phospholipids is also hydrophilic and hydrophobic. Cholesterol helps prevent extremes-- whether too fluid, or too firm-in the consistency of the membrane  Slightly immobilize the outer surface of the membrane and make it less soluble to very small water-soluble molecules.  Literally helps to keep the membrane from crystalizing

Transport Through Membranes Why are transport mechanisms needed to get through the membrane? Passive: 1.Diffusion 2. Carrier Protein Active: 1. Sodium Potassium Pump Why do ions not move through the membrane? Size Matters What Water! – How?

Energy Use No Energy Required 1. Osmosis 2. Facilitated Diffusion 3. Diffusion Energy Required A. Active Transport 1. Endocytosis A. Phagocytosis B. Pinocytosis Exocytosis - Vacuoles

Osmosis ch?v=sdiJtDRJQEc

Concentration 1.Solvent 2.Solute 3.Solution 4.Concentration salt in water = 12g/3L Vs. 12g/6L 5.Diffusion - once equilibrium is reached what happens? 6.Osmosis is the movement of what substance across what? 1.Isotonic 2.Hypertonic 3.Hypotonic 7.Selectively Permeable Membranes

1.Isotonic - movement of water in and out of cell is? 2.Hypertonic solution around red blood cell 3.Hypotonic solution around red blood cell Red Blood Cells

Hyponatremia – water intoxication Exercise causes sodium loss along with sweat. A study published in the New England Journal of Medicine (April, 2005) found that 13 percent of Boston Marathon runners developed hyponatremia from drinking too much water.. Adequate sodium balance is necessary for transmitting nerve impulses and proper muscle function, the early warning signs may be similar to dehydration and include nausea, muscle cramps, disorientation, slurred speech, and confusion