Osmosis
by Caroline Trew
1. Calculations:
1.1. π = MRT
1.1.1. π = osmotic pressure
1.1.2. M = molarity
1.1.3. R = gas constant (0.08206 L*atm / mol*K)
1.1.4. T = temperature in K
1.2. Ex: 0.30M glucose in H2O at 37 degrees Celsius. Find the osmotic pressure in atm.
1.2.1. π = MRT
1.2.1.1. π = 0.30 mol/L x 0.08206 L*atm/mol*K
1.2.1.1.1. π = 7.6 atm
2. Biological Applications
2.1. Cell membranes form a barrier between the contents of the cell and its surrounding biological environment
2.2. Osmosis helps regulate the distribution of nutrients and the release of metabolic waste products within cells in all living creatures
2.3. Without selective osmosis, the substances necessary to sustain the life of the cell would diffuse out into the cell's surrounding environment, and toxic materials from the surrounding environment would enter the cell.
2.4. If blood cells come contact with an isotonic solution, they will neither shrink nor swell. If the solution is hypertonic, the cells will lose water and shrink. If the solution is hypotonic, the cells will swell.
2.5. In plants, osmosis helps to draw water up from the plants' roots to its' leaves.
3. Code for Sphero Program:
3.1. on start program
3.2. roll 0° at 30 speed for 5s
4. Osmosis and Medicine
5. Preserving Fruits and Meats
6. Osmosis: the spontaneous net movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides
6.1. Solvent moves down its concentration gradient.
6.2. Osmosis may occur within a fluid or across a barrier (membrane)
7. Temperature and particle size affect the efficiency and rate of osmosis
7.1. Higher temperatures can cause osmosis to occur at a faster rate because the molecules carry higher energy and are more likely to move quickly through the selectively permeable membrane.
7.2. Smaller particles are able to pass through the membrane much more easily than larger molecules. Certain molecules are too large to pass through the membrane at all.
8. Isotonic, hypotonic, and hypertonic solutions
8.1. A solution is isotonic if the concentration of dissolved substances is the same as the concentration inside the cell. Osmosis does not occur in an isotonic solution.
8.2. A hypotonic solution is a solution in which the concentration of dissolved substances is lower than the concentration inside the cell. If a cell were put in a hypotonic solution, osmosis will cause water to move through the cell membrane into the cell.
8.3. A solution is hypertonic if its concentration of dissolved substances is greater than the concentration inside the cell. If a cell were placed in a hypertonic solution, it would lose water.
9. Solute: substance which can be dissolved by a solvent (any fluid capable of dissolving the solute). All biological processes occur in water which is sometimes called the universal solvent due to its ability to dissolve many different solutes.
10. Concentration of a substance: amount of a solute in the given amount of a solvent. The concentration of sugar is a measure of the number of sugar molecules found in a certain volume of solution.
10.1. high solute concentration + low solvent concentration | low solute concentration + high solvent concentration
10.2. → equal solute concentration + equal solvent solution | equal solute concentration + equal solvent solution
11. Gradient: difference in factors such as pressure, temperature, solute concentration, and electrical charge found in fluids between two adjacent regions.
11.1. Gradients across cell membranes are essential for life within the cell. Without gradients, the cell is dead. Proteins in cell membranes use energy to create and maintain concentration gradients because these concentration gradients between certain molecules underlie many crucial biochemical processes.
12. "Selectively permeable" is the term used to describe the characteristic of a membrane which allows certain molecules or ions to move through it more easily than others.