The plasma membrane A phospholipid Amphiphilic o Hydrophilic Likes water o Lipophilic Likes fat Hydrophilic heads o Sticks out of Hydrophobic tails o Inside of the membrane o Away from water o o o o o 98 of molecules in plasma membrane are lilpids Phospholipids Cholesterol Glycolipids Contributes to glycocalyx Transmembrane proteins Second messengers Membrane transport Plasma membrane a barrier and a gateway between the cytoplasm and extracellular fluid ECF Passive transport mechanisms require no ATP Active transport mechanisms consumes ATP 1 Filtration a Particles are driven though a selectively permeable membrane by hydrostatic pressure i Hydrostatic pressures 1 The movement of blood that move the things out of the capillary wall ii Blood getting water salts nutrients and other solutes are gotten to the tissue fluid iii Kidneys filter waste from the blood 2 Simple Diffusion a The movement form area of high concentration to area of low concentration i Sugar cube in water The sugar will diffuse ii Sugar cube in sugar water b Factors affecting diffusion rate through a membrane i Temperature 1 Increase the rate of diffusion if increase of temp ii Molecular weight 1 The higher the molecular weight the slower the rate of diffusion iii Steepness of concentration gradient 1 How much difference between high and low concentration 2 More the difference the higher and lower concentration the faster you will get diffusion 3 After exercise glucose is higher eat a meal the stuff with diffuse faster a iv Membrane surface area 1 Greater the surface area that is exposed of a molecule the greater diffusion v Membrane permeability 1 The greater the permeability of the membrane the greater diffusion 2 Smokers their blood vessels are less permeable to the glucose and it will stay in the vessels c Diffusion through lipid bilayer i Properties of a molecule to go through the membrane 1 Small 2 Not charged 3 Hydrophobic d Diffusion through channel proteins i Membrane proteins that act like channels ii Properties 1 Hydrophilic 3 Osmosis a Flow of water from one side of a selectively permeable membrane to the other b Selectively permeable membrane in a beaker i If not selectively permeable it will let all molecules go back and forth including water ii In selectable permeable the sugar will not move buthe wat er will iii Side A Water plus Solute sugar iv Sibe B Water v Water will move from B to A vi In the beaker the only way to change the peramiblity is to change the membrane 1 In our bodies we have proteins that can express higher rates 2 Aquaporins a Water channels protests that allow movement of water b These increases the amount of water that you re kiney holds onto during dehydration Osmotic pressure and Tonicity Osmotic pressure o Hydrostatic pressure required to halt osmosis o To stop water in a hose we put our thumb over it o To stop movement of water from B to A we have to put a stopper o The osmotic pressure is the amount of pressure applied to side A but not to side B that we need to apply to keep movement form B to A It s about air pressure Properties of liquid and are Apply pressure to the air over a liquid it applys pressure to liquid also Applying a higher pressure to side B means you have less pressue on side A o You have conteracted the flow between the membrane This happens in body tissues Diabetes prevents the flow Blood flow out of the heart You want high pressure down low Lungs Oxygen into the blood and carbon dioxide out of the blood and into the lung Don t want pressure high so that carbon dioxide in the blood and it stays Want carbon dioxide pressure low in the lung Tonicity is measure of this pressure Tonicity the ability of a solution to affect the fluid volume and pressure in a cell Have to have a reference point Hypertonic relative to what Another way we can think about osmotic pressure What is the pressure of the solution on side A Tone concentration of solutes on side A o This equals osmotic pressure Hypertonic Greater than Solution is one with a higher concentration of no permeating solutes the ICF Isotonic Same Hypotonic Below Lower concentration of no permeating solutes than the intracellular fluid Effects of Tonicity on RBCs Red Blood Cells Hypertonic solution o Has a higher concentration of non permeating solutes o Crenate Shrivel When the water exits the cell 5MNaCL Has a greater concerntaion of sodium chloride o RBC has 5 o Solution has 50 outiside o Put it into a solution that is Hypertonic compared to RBC o In a hypertonic solution Water will flow out of the RBC into the solution