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Osmosis

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you know what word gets thrown found a lot but is actually pretty challenging to understand  osmosis but it does answer some great questions like why would it be deadly if someone an IV of pure water or why would a saltwater fish placed in freshwater experienced major problems will answer these questions as well as explain the cast of Osmosis the first understand osmosis is the movement of water and that really is a type of diffusion often when you're talking about osmosis talking about the movement of water through a semi-permeable membrane like a cell membrane cell membrane has opening small enough for water molecules to pass but it will not allow larger things like salt molecules to freely pass at least not without assistance osmosis is a type of passive transport it doesn't require energy I mentioned us Moses is a type of diffusion and similar to what you might have learned about with diffusion molecules in this case water travel what areas of high concentration of water to low concentration of water but there's another way to think about water movement in osmosis water concentration likely means there are a lot of solutes solutes are substances like salt or sugar that can be dissolved within a solvent what are water has the tendency to move to areas where there is a high solute concentration which means there's less water concentration so if you want easily figure out where the water will travel look to the side where there is a greater solute concentration so let's imagine you have a box a semipermeable membrane in the center and remember this membrane will that tiny things pass through it like water and gases but not large solutes next Salt one side of the box and one side of the Box be if you have pure water on both sides of the Box those water cuz they're moving water molecules they like to move but the net movement of water on the two sides is zero meaning the overall change in direction of is zero now let's imagine on side B you dump a huge amount of salt their salt molecules are too large to pass through this membrane which direction will the water move towards A or B the answer is beat this area has a high cell concentration and remember water moves to areas of higher solute concentration you can almost think of the water is trying to equalize the concentration diluting side be once equilibrium is reached the net movement of water on the two sides will be zero but remember that water still likes to move and movement still occurs vocabulary call side B hypertonic you know that prefix hyper when you think of a hyper person helps me think of a high amount of something for hyper person it might be caffeine but in our case it means a high solute concentration but we can't just say something is hypertonic without comparing it to something else we say that side B is hypertonic decide a because it has a greater solute concentration than side in osmosis water moves to the hypertonic side we say side a is hypotonic hypo rhymes with low helps me remember that it's a lower solute concentration at least when compared to side beat so let's do some real life examples now because this box thing is getting a little lowering when someone gets an IV in the hospital it may look like the clear fluid running through the IV is water but it is certainly not water that would actually be a disaster because of Osmosis hypothetically there was pure water placed in an IV now and IV tube typically runs through vein so that you have access to your stream really useful for running medication through blood actually consists of many different types of cells red blood cells are great example so what do you think has a greater cell concentration the hypothetical pure water in the IV tube or in the red blood cells remember cells are not empty vessels they do contain solutes the pure water that hypothetically is running through this IV tube has no solutes it's just pure water so where does the water go remember it goes to the area of higher solute concentration so it's going to go inside the cells the cells are high super tonic compared to the water in the IV tube because the cells have a greater solute concentration the cells would swell with water and possibly burst exploding red blood cells are not fun if a person needs fluids they typically receive a solution that is isotonic to their blood plasma isotonic means concentration so you wouldn't have any swelling or shrinking red blood cells and that's a good thing say you go to a pet store and you get a fish that looks like Nemo from the movie Finding Nemo a clownfish only you don't know what to saltwater fish what happen if you place this saltwater fish in freshwater Cowboy first ask yourself where is there a higher solute concentration in the saltwater fish cells or in the freshwater that you just this fish in definitely in the saltwater fish cells so where's the water going to go to the area where there's a greater solute concentration chronic side so it's going to go into that poor fish if you don't rescue it soon the cells would actually start swelling if you looked at them under a microscope eventually this fish and I know one thing to clarify saltwater fish and freshwater fish are not necessarily ISO tonic rumor that means equal concentration to their surround they have special adaptations that allow them to live in their environment and usually they can't make a major switch from Salt Water environment to a fresh louder environment had this amazing between fresh and saltwater they have to deal with this osmosis problem frequently salmon for example I think if I had to be a fish I'd be a salmon you know Moses also explains how many kinds of plants get their water sure many plants have Roots but how does the water get into the roots when it rains the soil come saturated with water the root hair cells have a higher concentration of solutes within them than the solutes in the saturated soil so the what are travels to the area that is hypertonic and in this case the roots or if you live in an area that gets ice you might be used to salt trucks sing the road right by the roadside bunch of salt on these plants virement around them very salty very high and solute concentration very hypertonic compared to the root hair so how does the water move into the root hair cells now well it doesn't many plants by salt at roadsides die the same kind sing to be tragic for Slugs we think slugs are misunderstood almost cute gastropods we understand that many gardeners find them to be pests in their Garden but you really don't like it when we hear of salt being placed on slugs it really is death by osmosis basically if salt is dumped on a slug you are outside environment of the slug right there next to it very hypertonic the slug is hypotonic to the Salt remember the water will go to the area of higher solute concentration to the hypertonic side so the water that was in the slug the moisture that the slimy slug needs travels out of the slug and the slug dehydrates you can get really technical with us Moses you explore formula to calculate are potential and that uses water travels to areas of lower water potential basically areas of lower free energy we will be going in what are potential calculations with the short clip but we like to think about water is loving solutes and avoiding pressure whenever determining where will the water no water is one of the most important molecules for life so the big picture here is in all topics of life it is really important to understand how water travels I just makes perfect and so we have some practice problems if you would like to test out your osmosis skills well that's it for the amoeba sisters and we were mind you to stay curious

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Osmosis

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