Transcript for:
Understanding Osmosis and Solutions

before we can talk about osmosis let's do a quick review about Solutions Solutions have a solute like salt or sugar that gets dissolved in a solvent such as water okay so now that we know what Solutions are check out this experiment this tube has a membrane right here that separates two solutions the solution on the right has a higher concentration of solute and the solution on the left has a lower conc conentration of solute make a hypothesis what do you think is going to happen now watch what happens over time did you notice that the level of blue Solution on the right went up and the level of solution on the left went down can you explain why this occurs this happened because of Osmosis osmosis is the diffusion of water across a semi-permeable or selectively permeable membrane such as the plasma membrane that surrounds cells during osmosis water diffuses down its concentration gradient from higher to lower water concentration just like other molecules or ions you can also say that water moves from an area of lower solute concentration to an area of higher solute concentration sometimes this confuses people but if you think about it it makes sense for example a solution with 1% solute is 99 9% water but a solution with 20% solute is only 80% water the higher the solute concentration the lower the water concentration and vice versa in our experiment water moved toward the area with the higher solute concentration here's an easy way to remember the direction that water will flow during osmosis water follows solute if you can remember that you're basically all set but we do use a few terms to describe relative solute concentrations that you need to know one hypertonic if we are comparing two solutions the area with the higher solute concentration is hypertonic water will always flow across a membrane toward the hypertonic solution remember water follows solute two hypotonic this is the solution with a lower solute concentration water will leave a hypotonic solution by osmosis three isotonic if two solutions have the same solute concentrations they are isotonic the amount of water moving between isotonic Solutions is equal so there is no net change in water amounts between the two solutions now let's look at some real blood cells undergoing osmosis these cells are in a hypotonic solution make a hypothesis what do you think will happen the cells popped because water moved into them by osmosis the cell's cytoplasm has a higher concentration of solute than the distilled water they're floating in so water rushed in and caused them to explode now let's look at the opposite effect here's an egg that has had its shell removed by being soaked in vinegar overnight we are going to soak it in corn syrup a hyperonic solution look at how thick the corn syrup is that is because it is very concentrated with sugar a solute let's speed this up Watch What Happens as the egg soaks in the hypertonic corn syrup notice how it shrinks and becomes shriveled up like a raisin this is because it loses water due to osmosis to practice more with osmosis check out the interactive experience at biomanbio.com Linked In the description if you are enjoying these videos please feel free to like And subscribe