Phosphate-Buffered Saline (PBS) was used to clean the excess media in the cell and to maintain the osmolarity of the cells. In the cell and tissue culture, PBS was needed to remove the serum of media for trypsin to detach the cells from the flask . The salt ions in the PBS was isotonic to the cell because of equal amount of salt ions inside the cells. The cell will burst if the solution contain a few of salt ion and would be shrink if too much contain of salt ions. Therefore, the amount of salt ions and osmolarity in PBS must be correct to keep the cells in an isotonic state.
I obtained the results from the experiment supported my predictions because as the the concentration Na+ Cl- was increased from 5 mM to 10 mM (by adding more Na+ Cl-), the osmotic pressure also increased. However, after the membrane was changed to 50 MWCO, the Na+ Cl- molecules could diffuse easily through the membrane and did not caused an increase in osmotic pressure.
In this lab experiment, half our group observed and measured osmosis using dialysis tubes that were represented as the semipermeable membrane. It is permeable to water and other small molecules but is impermeable to larger molecules such as the sucrose solution used in each of the four beakers and tubing. The other half of our group observed the tonicity of sheep blood to determine whether the blood was isotonic, hypotonic, or hypertonic. The 85 g/dL of NaCl solution was the ideal isotonic number in relation to the sheep blood cells as well as a reference to the other observations of the solutions.
This exercise is aimed at giving a better understanding of the process of osmosis by analyzing how the decalcified eggs behave under different experimental conditions. The shell-less eggs used represented a model for a living cell and its selectively (semi) permeable membrane.
Osmosis is a natural occurrence constantly happening within the cells of all living things. For osmosis to occur, water molecules must move across a semipermeable membrane from an area of low concentration to an are of high concentration. In order to understand osmosis, people must understand the different types of concentrations that can be present within solution. One of them is an Isotonic solution where the concentration of dissolved particles is equal to that of a cell’s. Another is a hypertonic solution where there is a higher concentration of dissolved particles then inside the cell. And lastly there is a hypotonic solution where there are less dissolved particles than inside the cell. As dissolved particles move to a region of lower concentration, water moves the opposite direction as a result of there being less water in the highly concentrated region. In this experiment, gummy bears were placed in salt water, sugar water, and tap water to find the measure of osmosis between the solution and gummy bear.
Purpose: The purpose of this lab is to familiarize you with osmosis and, specifically, what happens to cells when they are exposed to solutions of differing tonicities.
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
Ive actually conducted an experiment where three potato strips were put into three different solution: distilled water, 10% NaCl, and 85% NaCl. The potatos were left in the solutions for fortyfive minutes. The experiment is to test different versions of osmosis. After fortyfive minutes had passed I took the potatos out of the solutions, and observed the results. The potato that was in the 10% NaCl solution was still firm, but slightly bendable. The potato strip that was in the distilled water was hard and rigid. To sum it up the effects to the potato strips were the same effects as the blood cells in the drowned victims. The hypotonic ones swelled up and gained water, while the hypertonic ones shriveled up and lost
A very carefully regulated process is solute concentration. If there is a sudden increase in water which enters the extracellular fluid, sodium ions will then contribute less to the extracellular solute concentration as the ratio between water and solute has now changed. Osmolality is the amount of solute in a kilogram, hence the osmolality in the extracellular space has also decreased.
Table 1 shows the contents of the bags and the content of the concentration it was submersed in. Bags 2-4 each contain a solution of both sucrose and water. These bags were each put into beakers containing hypertonic solution. These bags gained weight over time because the water moved from its high concentration inside the beaker to the low concentration inside the membrane of the artificial cell, the membrane being the bags that consisted of dialysis tubing. The
In this experiment, we will investigate the effect of solute concentration on osmosis. A semi‐permeable membrane (dialysis tubing) and sucrose will create an osmotic environment similar to that of a cell. Using different concentrations of sucrose (which is unable to cross the membrane) will allow us to examine the net movement of water across the membrane.
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.
Exercise 1: Cell Transport Mechanisms and Permeability: Activity 3: Simulating Osmotic Pressure Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. Which of the following is true of osmosis? You correctly answered: c. It is a type of diffusion. 2. Which of the following occurs when a hypertonic solution is added to cells? You correctly answered: d. The cells shrink. 3. The variable that affects osmotic pressure is You correctly answered: a. the concentration of nondiffusing solutes. 4. The net movement of water would be into the cell in a You correctly answered: b. hypotonic solution.
The three tissues being analyzed in this experiment, those of the kidney, heart and liver, were taken from the animal Bos taurus. The tissue homogenates used were made by adding 1 gram of tissue to 20 ml of sucrose phosphate buffer. The buffer was composed of 250 mM sucrose, 50 mM NaPO4, with a pH of 7.4. This mixture was homogenized with a high-speed blender for 3 pulses for a duration of 10 seconds each. The homogenates were then filtered through a cheesecloth and stored at -70° C.
Victor Andrew Lopez Week 1 – Case Study MKTG 425 – DeVry University Professor Eckert Statement of the Problem Value-added selling is a way in which the salespersons use to ensure that they add value to their customers hence increasing the experience of the customers. The study brings the ways in which the salespersons use to ensure that their customers have enough experience on their products. The need for the understanding of the ways in which Marcus Smith can create value for his customers and hence get more of them with the experience on the market issues. The value selling is more than a sales course since it takes the initiative of the salespersons to ensure that there is value added selling. It is also not true that people always want to get as much as they give, in the study there is a the detailed discussion of the ways in which value can create although sometimes it may not work for all customers (Albrecht et al., 2005).
10 ml of Phosphate Buffer saline (PBS) PH 7.2, 1 gm of glass beads and 1 ml of chloroform were added to each tube. The tubes were closed and shaken vigorously for 20 minutes using a mechanical shaker. All tubes were spun for 20 minutes at 1500 g in a refrigerated centrifuge. Fecal suspensions were stored at -20 ○C till using [11].