Osmosis

osmosis is the net movement of a solvent, usually water across a semi permeable membrane. Now this semi permeable membrane is just a material that's allowing solvents and other small molecules to pass across. And we're going to say that these cell membranes are around living that are around living cells are in fact semi criminal themselves. Now these cell membranes, they prevent salutes from passing through and these salutes can be ions or large molecules. Now, if we take a look here at this illustration of a semi permeable membrane here, the membrane is asking if you have an appointment. This larger molecule in red is trying to get through and they can't get past the barrier. But the smaller ones down here do have an appointment are allowed to pass through because they are the right size and they can pass through the semi permeable membrane to the other side. And this is the way that semi permeable membranes work. Osmosis is the movement of water net movement of water. But semi permeable membranes can halt and stop certain molecules from traversing from one side to the other side of a living cell.

Now, when it comes to osmosis, the solvent moves from a lower concentration solution to a higher concentration solution. Now, eventually, as it's doing this equilibrium will be reached and the net flows. Solvent is stopped by osmotic pressure. Now osmotic pressure itself. This is the pressure exerted on the semi permeable membrane by the solvent. If we take a look here we have these two images realized that the blue spears are are solvent molecules. So think of them as water and the red ones are are solute molecules. If we look at the image on the left, we can see that there are more red solid molecules on the top portion than on the bottom portion. That means the top part is more, uh, saturated, more concentrated because of this. Remember osmosis solvents want to move towards the higher concentration. That means that there's going to be greater osmotic pressure on this side here, which is going to force the water to go up towards the more concentrated side. So it's gonna start happening. Is water is going to move through the semi permeable membrane and try to basically dilute this more concentrated portion. So we think that the flow of solvent is up now, eventually, the they're both going to be the same type of concentration. Okay. I mean, I look like it, but just realize the flow of water is gonna dilute the top part. So it's gonna be more volume per the same number of solvent molecules. As a result of this, the pressure on both sides of the semi permeable membrane this membrane are going to be equal in force, so there's not gonna be a net flow of water. So we're gonna say here that the flow of solvent, the net flow would be zero. Right? We're going to say that, uh, there's not gonna be a big change. Water still flowing both ways. But one side is not gaining more water than the other side. So there's not a net change in volume for either side. So just remember, it's osmotic pressure that's going to stop this movement of water more so to one side than the other. This happens when the concentrations of both sides reach the same value. Okay, Initially, the more concentrated side is going to be diluted by the less concentrated side

here, osmosis is best defined as the movement of Remember osmosis. Osmosis is the movement of a solvent across the semi permeable membrane. Our solvent typically is water, so it's a movement of water molecules. So that means being sear out and let's see across the semi permeable membrane into a region of low salt concentration. No, not low high. Because of that, they can't be the answer. Therefore, D's a correct one, where water molecules move across the cell membrane into a region of high solute concentration. So here option D would be the correct answer.

we know that osmosis is the movement of a solvent from an area of low concentration to an area of high concentration. Now the direction of solvent flow depends on to necessity, Tony city itself is just the relative concentration of saul utes dissolved in the solutions. And when we take a look at the different types of solutions, realize that we're looking at solution concentration and osmotic pressure relative to one another. If we take a look here we have our hipaa tonic solution are isotonic solution and our hyper tonic solution with with a hip atomic solution. It has a lower salt concentration and lower osmotic pressure relative to bodily fluids. And when we talk about isotonic solutions, this is when two solutions have the same saw you concentration and osmotic pressure. Now an interesting piece of information is when we deal with intravenous solutions, they must be isotonic to bodily fluids such as blood plasma, tissue cells, tissue fluids, etcetera. And then finally we have hyper tonic solutions which has a higher salt concentration and osmotic pressure relative to body fluids. Now, if we take a look here, we're gonna talk about HIPPA tonic ice, atomic and hyper tonic environments and look at them in reference to their salt concentrations outside the cell. Osmotic pressure outside the cell and the effects they have on red blood cells. So when we're looking at hipAA tonic solutions, we're going to say they have lower solute concentration. We said isotonic, they would have equal saw you concentrations between two things being compared to one another. Hyper tonic would have higher solute concentration. Now, what about their osmotic pressure outside the cell? Well, lower salt concentration would result in lower osmotic pressure here. The equal amount of solute concentration would equate to an equal osmotic pressure. Higher, Higher solute concentration will result in higher osmotic pressure. What effect does this have on a biological system such as a red blood cell? Well, here we are going to say that we have lower concentration on the outside. So that would mean that it's more concentrated within the red blood cell. So remember osmosis moves to where it's higher in concentration. So water would enter the cell. This causes a process known as him. A license. So basically the cell will swell up because all the water is going in there and if too much water gets in there it can burst. Okay, so the cell will swell and then could burst. Next we have an isotonic environment. So the concentration inside and outside the red blood cells are the same. So water enters and exits the cell at equal rates. So there is no net movement of water. The same amount that goes in is the same amount that comes out. Finally, if we're in a hyper tonic environment, that means that it's more concentrated on the outside of the red blood cell. So water is going to exit the cell. If enough water exits the cell, this causes cremation. So the cell will dehydrate and it tribbles. Now, how's a way for us to remember these different types of situations? Well, here let's say we're looking at a hip a tonic environment. So hip a tonic environment, hippo sounds close to hippo, hippos, drinks a hippo drinks too much water and swells like a cell. So hippos were taking a huge amount of water because the environment is hip a tonic and they could burst or swell hyper tonic environment. So the outside is more concentrated than the red blood cell. So hyper tonic environment can be related to a hyper kid. The hyper kid playing outside gets dehydrated like a cell. So if your environment is hyper tonic you're gonna lose water out of your red blood cell, it's gonna exit the red blood cell and try to dilute the outside environment. So just keep these little memory tools to help you know, the distinction between high platonic versus hyper tonic isotonic. We know everything is equal on the inside and out. So there's no net movement of water

here, it says label the tenacity of the solution outside the cell where the dot the purple dot Are these solid particles. All right, So what we have to do is we have to look at how many dots we have on the outside and compared to the number of dots on the inside. In the first image, we can see that inside the cell is more concentrated outside. The cell is less concentrated, has less purple dots. Remember, we have to discuss what what type of solution is on the outside. Since the outside is less concentrated, it is a hypo tonic solution. For the 2nd 1, Both the inside and the outside have five purple. So five solid molecules, they're equal inside and out. So this would have to be an isotonic solution. Yeah, and then finally, here we have the outside having more dots so outside is more concentrated. Since the outside is more concentrated, this represents a hyper tonic solution. So just remember, we're looking at what the solution is on the outside relative to what's inside a particular self