Simple Diffusion

Movement of Molecules in CellsDiffusionFacilitated DiffusionActive TransportOsmosis

You will need sound!!!Simple Diffusion

How many types of molecules are there? (two)How many of each type are found on each side of the membrane? Triangle: 14 on left, none on right Circles: 12 on left, 13 on rightWhich shape is larger? TriangleDescribe the direction of the movement of the molecules? (They move in all directions)Which moolecules are abel to pass through the semi-permiable membrane? The dots, because they can fit through the gaps, and because you since they are equal on both sides, they are moving back and forth at random.If you came back after a while, would you expect to find any change in concentrations of the molecules on either side of the membrane? No, the concentrations would be the same high on the left and none on the right, because they cant pass through. Circles will stay evenly distributed on both sides of the membrane due to random movement.2Selectively Permeable Membrane

What two major types of biomolecules compose the majority of the cell membrane in this model? Phospholipids and proteinsHow many different protein molecules are found in this model? 4 2 types of surface proteins and two types of membrane-spanning proteinsWhat is the difference between the position of the surface proteins and the membrane-spanning proteins? Surface dont reach through.When a carbohydrate chain is attached to a protein, what is the structure called? GlycoproteinWhen a carbohydrate is attached to a phospholipid, what is the structure called? GlycolipidWhat types of molecules are shown moving across the membrane? Small polar and nonpolar moleculesWhere exactly in the membrane do these molecules pass through? BETWEEN the phospolipidsHow does the concentration of the small molecules inside the cell compare to that ouside the cell? More are outside, so the concentration is higher outside, compared to inside.Does the model indicate that the molecules are moving in equal amounts in both directions? No, more are moving into the cell than outside the cell. The arrows show the movement. 3Diffusion SummarizedDIFFUSION happens because of a CONCENTRATION GRADIENT: when there is a difference in concentration of a particular particle on either side of the membrane.Particles move along the concentration gradient from the area of high concentration to the area of low concentration, until EQUILIBRIUM is reached.The net movement of particles along the concentration gradient is called DIFFUSION

FACILITATED DIFFUSION

ACTIVE TRANSPORT

Passive vs. Active Transport

OSMOSIS

Outside the cell:High sugar concentration (15 outside vs. 6 inside )Low water concentration (15 outside vs. 24 inside)Inside the cell:Low sugar concentrationHIgh water concentration

Osmosis in Plant and Animal Cells