In this lab, the purpose of it was to examine and observe diffusion and osmosis moving through through a membrane and to investigate the effects of solute concentration on water potential. It started off with the two dialysis tubes that was filled with 10mL of distilled water and three drops of phenolphthalein. Then added 10 drops 1M of sodium hydroxide and 20-40 drops of iodine in two different beakers filled with distilled water. The dialysis tubes were placed in the beaker then gradually started to change color. This experiment showed that dialysis tubing is selective in its permeability to molecules. It was permeable to glucose and iodine but not starch. Also another objective of this experiment was to see how hypotonic and hypertonic solutions …show more content…
Diffusion is the movement of an element or object across a membrane. Osmosis has to do with the diffusion of water. Osmosis allows water to move from areas of high concentrations to low concentrations. An example of osmosis is blood cells absorbing water. Osmosis is highly important in the survival of cells. There are certain types of solutions that cause cells to act in these ways. If there is more solute inside of a cell than outside, water will move into the cell in order to reach an equilibrium. This is known as a hypotonic solution. As water moves into the cell, and enough pressure builds up, the cell with burst and die. If there is more solute outside the cell than inside, water will move out of the cell, causing the cell to shrivel up, and possibly die. This is known as a hypertonic solution. When the solute is equally balanced inside and outside of the cell, the solution is isotonic. The water moves in and out of the cell at a consistent rate and an equilibrium has been reached. This lab tested the rate of osmosis and diffusion in cells. To test diffusion and osmosis out in this experiment, further dialysis tubing was used. It also proven that both of the dialysis tubing testing with the beakers is selective and only permeable to glucose and iodine. It demonstrated different water solutions such as hypotonic and …show more content…
Then the and with the blood cell testing that it takes higher concentration for the blood cells to become smaller
Diffusion is well known for the movement of particles from an area of higher concentration to an area of lower concentration. In diffusion, water does go into and out of a selectively permeable membrane and this is known as osmosis. The selectively permeable membrane only consist of water also other very small particles can be diffused through this process. The cell membrane is similar to the dialysis tubing which was used in this experiment so it didn't lose any water. The solution on the dialysis tubing had a higher concentration of solutes than distilled water. The beaker represented a hypotonic solution, one in which the concentration of dissolved substances is lower than the concentration inside the dialysis tubing. Osmosis caused water to move through the dialysis tube. The dialysis tube represented a hypertonic solution, one in which the concentration of dissolved substances is greater than the concentration outside the
help give a better idea of how the rate of osmosis is affected by the
This process can also be defined as osmosis, which is the diffusion of water molecules across a membrane. (Unknown, 2) When we first got the egg it would be an isotonic solution meaning that it had equal tension (Unknown,1) which would mean that the same amount was inside the cell as outside of it. The purpose of the experiment was to learn about diffusion, concentration gradient, passive transport, equilibrium, osmosis, tonicity, hypertonic solutions, hypotonic solutions, isotonic solutions, and osmoregulation. If I put the egg in corn syrup, then the egg will deform because it has been placed in a hypertonic solution.
Once the paramedics retrieve Marc, he will have a high concentration of salt in his blood and fluids. This means that the paramedics would treat him with the half normal saline. This is the solution with the lowest percentage of solutes (0.45% NaCl).this will increase his concentration of water throughout this body and will return his cells to their normal size. However, if the paramedics were to keep him on the half normal saline for too long, his water concentration would be too high and his solute concentration would become too low. This would mean that the paramedics would then need to switch Marc to the normal isotonic saline solution (0.9% NaCl). This would balance out both the concentration of water and solutes so that they are now equal. This would set his balance and homeostasis back to normal, thereby helping his recovery. (Johnson
I also predict that solution concentration 0.3 will be isotonic because of the pressure potential. As the water moves into the cell it pushes up against the cell wall this is called the pressure potential and it increases the water potential until an equilibrium is reached, and because the cell is so inelastic it takes very little water to achieve this. That's why I believe in-between 0.3 and 0.4 will be isotonic as it is very close to pure water. Background Information Osmosis - The net movement of water molecules from a region of high water potential to a low water potential, through a selectively
This cell membrane plays an important part in Diffusion. Cell membrane and Diffusion Diffusion is the movement of the molecules of gas or liquids from a higher concentrated region to a lower concentration through the partially permeable cell membrane along a concentraion gradient. This explanation is in the diagram shown below: [IMAGE] Turgor When a plant cell is placed in a dilute solution or a less concentrated solution then the water particles pass through the partially permeable membrane and fill the cell up with water. The cell then becomes Turgor or hard. An example of this is a strong well-watered plant.
If the concentration of one side of the membrane is greater than the molecules will travel from the higher to lower concentration. Eventually there will be a dynamic equilibrium and there will be no net movement of molecules from one side to the other. Osmosis is the diffusion of water. Like diffusion, the water moves from a region of higher water potential to a region of lower water potential.
The experiment is aimed at giving a better understanding of the osmosis process and the different conditions in which osmosis occurs. INTRODUCTION When a cell membrane is said to be selectively permeable, it means that the cell membrane controls what substances pass in and out through the membrane. This characteristic of cell membranes plays a great role in passive transport. Passive transport is the movement of substances across the cell membrane without any input of energy by the cell.
Osmosis is the facilitated diffusion of water across the cell membrane of a cell. The inside layer of the cell membrane is hydrophilic, meaning water cannot easily pass through the membrane. The cell membrane has to have aquaporins, which are water channel proteins, that move the water across the membrane. If there is a water and salt solution outside the cell, the salt can enter the cell by diffusion, but the cell membrane is not permeable to the water. Because there is more solute solution inside the cell, there is less water. The aquaporins move the water across the membrane until equilibrium is reached.
In life, it is critical to understand what substances can permeate the cell membrane. This is important because the substances that are able to permeate the cell membrane can be necessary for the cell to function. Likewise, it is important to have a semi-permeable membrane in the cell due to the fact that it can help guard against harmful items that want to enter the cell. In addition, it is critical to understand how water moves through the cell through osmosis because if solute concentration is unregulated, net osmosis can occur outside or inside the cell, causing issues such as plasmolysis and cytolysis. The plasma membrane of a cell can be modeled various ways, but dialysis tubing is especially helpful to model what substances will diffuse or be transported out of a cell membrane. The experiment seeks to expose what substances would be permeable to the cell membrane through the use of dialysis tubing, starch, glucose, salt, and various solute indicators. However, before analyzing which of the solutes (starch, glucose, and salt) is likely to pass through the membrane, it is critical to understand how the dialysis tubing compares to the cell membrane.
So what is happening is water is moving from a high concentration, i.e. a dilute solution to a more concentrated solution. Preliminary Work on Osmosis I am going to test carrots in a small osmosis experiment to see how the experiment works with carrots and salt solution and water. Variables 1) Temperature - Keep the same 2) Number of days left soaking - Keep the same 3) Size of beaker - Keep the same 4) Size of carrots - Keep the same 5) Concentration of salt solution -
the gain or loss of water when samples of the tissue are placed in a
-The cells in the body will increase because osmosis causes molecules to move from a less concentrated solution to a more concentrated solution.
Most cell membranes are like that, being permeable to water and some solutes only. Osmosis is therefore the diffusion of water through a partially permeable membrane. The basic principles of diffusion apply here.
However not in sucrose, the RBCs were semi-permeable. RBCs diffuse in the water around five minutes, but in glycerol RBCs diffuse in fifteen minutes. Several factors are involved that affect the rate at which the RBCs diffuse, could have been because of the size, polarity, or the charge of the molecule. Urea is the carbonic acid found in urine, blood, and lymph; it is formed in the liver from amino acids and ammonia. It is important that urea is permeable because the amount of urea in the body is essential because it helps undergo waste product. Glycerol is combination of sugar and alcohol. This solution is an important component for storage of fats that are ingested into the body as food, this one good reason why glycerol is permeable. Sucrose however has low permeability which is why sucrose has a slow rate of diffusion and glycerol and urea on the other hand has fast rates of
The purpose of this lab was to see firsthand the diffusion of a substance across a selectively permeable membrane. Diffusion is the movement of molecules from an area of high concentration to an area of lower concentration until both concentrations are equal, or as you could more professionally call it, equilibrium. This concept is one that we have been studying in depth currently in Biology class.