Lab Analysis Of The Dialysis Of Osmosis

“Essential Biology with Physiology” by Simon, Dickey, Hogan, and Reece, defines osmosis as follows: “The diffusion of water across a selectively permeable membrane is called osmosis.” An experiment was done in BIO 100 regarding osmosis. 5 different teams got together and each of them has a task. To record the weight change in potato strips that have been placed in different concentrations of salt solution after 30 minutes. The groups were to observe the change in weight. The movement of water through cells is often called osmosis. Osmosis applies to the daily life in many different ways. Osmosis assists plants in receiving water, it helps in the preservation of fruit and meat, is used in kidney dialysis, and can be reversed to remove salt and other impurities from water. Osmosis is a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane. If the solution was hypertonic, more water would move out of the potato. If the solution was hypotonic, more water would move into the potato. Our group had a 0% solute concentration so our hypothesis was that it would be a hypotonic solution, and the potato would absorb the

The experiment of the lab was to demonstrate knowledge of the concepts of diffusion and osmosis. Diffusion is the movement of substances moving from a high concentration to a low concentration. For this lab the rate of osmosis was measured in concentration. The concentration stayed the same and increased through the experiment. At the beginning of the experiment the sacs were weighed to determine the tonicity of water throughout the experiment. Timing was also a factor each 15, 30, 45 minute interval the sacs were weighed and recorded. Each sac had a different amount of solution in them. The tonicity of the sacs was determined as well by the final weights and the final percent of gain or loss of water in the sacs.

The Osmosis and Diffusion lab was conducted to provide us with information on how built up mucus affects those conflicted by the recessive genetic disease, Cystic Fibrosis., due to a mutation to the membrane regulating chloride (Cl-). This mutation prevents the Cl- from leaving the cell causing the amount of sodium (Na+) in epithelial cells, which results in extreme mucus on the lungs and airways causing this disease to be fatal if not treated but treatment does not equate to a long lifetime. During the lab we took the data from three parts: Diffusion, Osmosis in an Elodea Cell, and finally the Role of Osmosis in Cystic Fibrosis. During Part 1 we looked at diffusion across a semipermeable membrane for starch and glucose, which resulted in both having a negative solution when placed in a semipermeable membrane. Then we looked at osmosis in the Elodea Cell to watch for the occurrence of Plasmolysis, when a cell’s plasma membrane pulls away from the cell, and how a plant cell is affected by both hypertonic and hypotonic solutions. Finally, we observed the role of Osmosis in Cystic Fibrosis using dialysis bags to represent a normal cell and a Cystic Fibrosis cell with the normal containing 1% NaCl while the Cystic Fibrosis bag contained 10% NaCl. After we ran the experiment, we looked at the Percent Change in Mass and compared them after 30 minutes. We found that Cystic Fibrosis cells didn’t change mass as much as the normal cell ending with a change in mass over -1%. The

The dialysis tubing will be clamped at one end in order to fill it and then clamped at the other end to seal the filled bag. If the bag is not soft and floppy, the experiment will not work. Blot a bag with a paper towel to absorb the moisture and weigh it, if this blotting process is not done it could interfere with the weight readings creating inaccurate information. After the bags of the solutions are prepared, they will be placed into five different beakers with different solutions. Beakers 1-4 will be filled with tap water and the fifth beaker is filled with 40% sucrose and water. Fill each beaker with just enough water or solution so that the bag is covered and place the bags in the beakers simultaneously and record each time. Every 10 min the bags are to be taken out, blotted, and weighed again before returning them back into their respective beaker for another 10 min. The process is repeated until you have reached 90 min. The weights should be recorded in grams (g).

Using the graduated cylinder, measure 20mLs of the stock sucrose solution and 180mL of water to create a 3% sucrose solution and place it into the 250mL beaker (beaker #2). Place bags #1‐3 (red, blue, yellow) into beaker 2 and bag #4 (green) into beaker 1. Allow the bags to sit for one hour. After allowing the bags to sit for one hour, remove them from the beakers carefully open the bags, noting that often times the tops may need to be cut as they tend to dry out. Measure the solution volumes of each dialysis bag using the empty 250 ml beaker.

If Michael’s mistake had been caught earlier, is there anything that could have been done to prevent the corn from dying?

The difference is that along with large molecules, living cells prevent molecules with positive charges and solubility. This is not representing in dialysis tubing, and is only found in living cells because the tubing is only based on molecular size (98). When referring the rate of diffusion, the concentration gradient influences the diffusion rate, based on the factors of temperature. The ability for molecules diffuse from high to low concentrations primarily depends on the concentration gradient between the two areas.(96-99). My hypothesis for the study is that in the hypotonic, hypertonic, and isotonic solutions, the direction and rate of osmosis will determine based on the concentration inside the dialysis tubing. My prediction is that if the solution is hypotonic the results will decrease, if the solution is hypertonic the results will increase and if the solution is isotonic the solution will vary and or remain constant.

The purpose of this experiment is to approximate the water potential of the potato cores and see how our results compare to other results out there. We also want to see how the water potential and osmolalities of the potato cores vary with sucrose and NaCl. There are three different theories of osmosis. The first is the concentration of water explanation. This theory says that pure water is more concentrated than water in solution because the solute would have to take up some space in the solution. One problem with this theory is that it says that because water is moving down a concentration gradient, water diffuses into a hyperosmotic solution

Osmosis is defined as the tendency of water to flow through a semipermeable membrane to the side with a lower solute concentration. Water potential can be explained by solutes in a solution. The more positive a number is more likely it will lose water. Therefore should water potential be negative the cell the less likely it will lose water. In using potatoes the effects of the molarity of sucrose on the turgidity of plant cells. According to Clemson University, the average molarity of a White potato is between .24 M and .31 M when submerged in a sorbitol solution. This experiment was conducted with the purpose of explaining the relationship found between the mass in plants when put into varying concentrations of sucrose solutions. Should the potatoes be placed in a solution that contains 0.2M or .4M of sucrose solution it will be hypotonic and gain mass or if placed in .6M< it will be hypertonic and lose mass instead. Controlled Variables in this lab were: Composition of plastic cups, Brand of Russet Potatoes, Brand of Sweet Potatoes and the Temperature of the room. For independent variable that caused the results recorded it was the different Sucrose concentrations (0.0M, 0.2M, 0.4M, 0.6M, 0.8M, 1M). The dependent variable was the percentage change from the initial weighs to the final. The cup with .4 molarity was the closest to an isotonic solution and was used as the control group for the lab. Water potential is the free energy per mole of water. It is

This means that they were submerged into a hypotonic environment and the water permeated the membrane from the beaker into the dialysis bags. The result was more so in the dialysis bag with a higher concentration of sucrose. The same occurred with the bag of RO water submerged in sucrose except that the bag was in a hypertonic environment and thus flowed out of the bag. The RO water bag submerged in RO water only changed mass in the first 15 minutes and then remained the same from the rest of the experiment once it had

Osmosis and diffusion are processes by which water and solute particles, respectively, pass through a selectively permeable membrane. When water moves across a cell membrane the processes of osmosis and diffusion take place to maintain a balance between the water and solute particles inside and outside of the cell by moving from a region of high concentration to a region of lower concentration. If the concentration of solute particles inside and outside the cell are equal then the solution outside the cell is referred to as isotonic, but if the concentration of solute particles outside the cell are greater or less than the concentration inside the cell then the solution is referred to as hypertonic (greater) and hypotonic (less). A hypertonic solution results in shrinkage of the cell as water leaves the cell via osmosis to compensate, while a hypotonic solution results in swelling of the cell as water enters the cell via osmosis.

Finally, the potato chunk placed in a solution with 1 molar of sucrose began with a volume of 2.025mm3, and decreased to a volume of 1.078mm3 overnight. This was a decrease in volume by 47%. This potato chunk in this solution began with a mass of 2.1 grams, and decreased to a mass of 1.3 grams, which was a 38% decrease in mass. Although the data presented does not include every data point collected, the main points shown represent how a plant cell will decrease in mass and volume when placed in a higher sucrose solution. This decrease of volume and mass is due to the plant cell being placed into a hypertonic solution.

In the ‘Adrift and Ahirst Lab’ slices of potatoes were used to represent our body cells. There was two types of solutions, a freshwater solution and a saltwater (10% salt) solution. Knowing this we wanted to discover which solution would cause the potato to change the most in terms of circumference and mass.

We will observe the process of diffusion and osmosis throughout our project. After all, osmosis really is a type of diffusion, which is the random motion of particles of liquids, gases, or solids. Osmosis is where free water molecules move across a selectively permeable membrane. Water molecules move from a region of high water concentration to regions of low water concentration. This selectively permeable membrane that moves water across it is a property of biological membranes that allows them to regulate the passage of particular substances across them (Urry et al., 2015). Although the selectively permeable membrane we use won’t be a cell membrane, the dialysis tubes have many similarities. It can be used to imitate a cell membrane since it’s made of cellulose that has microscopic pores for water to move in much like how it does with a cell membrane. Water that moves down its gradient concentration does it due to its water potential, since it favors to move to areas of lower water potential. The rate of osmosis increases as the concentration of solutes increases. It’s an example of a hypotonic relationship, as there’s more water molecules taken into the solution causing the mass to go in (Urry et al., 2015). We will look at molarity of the substances, a common measure that determines the number of moles of solute per liter of solution.

To understand how osmosis and diffusion worked we did a lab. The lab we did was on plant cells and animal cells. Osmosis is a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, equalizing the concentrations on each side of the membrane. Diffusion is the passive movement of molecules or particles along a concentration gradient or from regions of higher to regions of lower concentration. The difference between diffusion and osmosis is that diffusion refers to the movement of any chemical from one place to another, and osmosis exclusively refers to the movement of water across a membrane. Also, the lab that we did helped us to understand the difference between the three types of solutions. The three types of solutions are hypertonic, isotonic and hypertonic. An isotonic solution refers to two solutions having the same osmotic pressure across a semipermeable membrane. A hypotonic solution has a lower osmotic pressure than any other solution. A hypertonic solution is when the concentration of the solutes is greater outside the cell than inside of the cell. Tonicity is the measure of the effective osmotic pressure gradient, as understood by the water potential of two solutions separated by a semipermeable membrane. We