Natasha Tenen
Lab: Thursday (3-6 pm) OSMOSIS LAB REPORT
INTRODUCTION
Osmosis is a special type of diffusion where water molecules move down a concentration gradient across a cell membrane. The solute (dissolved substance) concentration affects the rate of osmosis causing it either to speed the process up or slow it down. Based on this, how does different concentrations of sucrose affect the rate of osmosis? If sucrose concentration increases in the selectivity-permeable baggies, then the rate of osmosis will increase.
MATERIALS AND METHODS
The start of the experiment consisted of filling up four beakers with de-ionized water to 150 ml. After the beakers were filled to the appropriate amounts they were then labeled with the
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Group 1 received 107% for 0.0m, 109% for 0.25m, 112% for 0.5m, and 126% for 0.75m. Group 2 received 100% for 0.0m, 107% for 0.25m, 116% for 0.5m, and 117% for 0.75m. Group 3 received 100% for 0.0m, 106% for 0.25m, 114% for 0.5 m, and 117% for 0.75m. Group 4 received 100% for 0.0m, 106% for 0.25m, 113% for 0.5m, and 116% for 0.75m. Group 5 received 98% for 0.0m, 105% for 0.25m, 110% for 0.5m, and 115% for 0.75m. Group 6 received 104% for 0.0m, 108% for 0.25m, 111% for 0.5m, and 104% for 0.75m. The trend line that occurred for the rate of osmosis was an upward increase as the solute concentration increased.
DISCUSSION
The class data that was received supported the group members’ hypothesis that the rate of osmosis will increase if the sucrose concentration increases as well. The trend line that was received from the data also supported the hypothesis because it increased as the sucrose concentration increased. The initial weight gain percents were all different because all of the groups’ sugar concentrations were not completely identical. The method used wasn’t entirely accurate because there could’ve been some flaws such as some bags weren’t secured enough and might have leaked sucrose into the de-ionized water causing the results to be different. The bags might have not been washed thoroughly which could have ultimately allowed sucrose into the de-ionized water. The results could have been more accurate if the baggies were left in the
In this experiment you will be using different percentages of sucrose solutions and food coloring along with dialysis tubing to visibly and physically display osmosis. Osmosis is the diffusion of a solvent across a semipermeable membrane to reach an isotonic state (Fitzhugh 47). A solution becomes isotonic when there is an equal amount of solvent flowing evenly through a semipermeable membrane in and out of dialysis tubing. The purpose of this experiment is to better understand what happens during osmosis and to be able to recognize that it happened. I predicted that, if the percentage of sucrose was higher in the beaker than in its corresponding dialysis bag, then the weight of the dialysis bag would increase and vice versa.
The lab for this paper was conducted for the topic of osmosis, the movement of water from high to low concentration. Five artificial cells were created, each being filled with different concentrated solutions of sucrose. These artificial cells were placed in hypertonic, hypotonic, or isotonic solutions for a period of 90 min. Over time, the rate of osmosis was measured by calculating the weight of each artificial cell on given intervals (every 10 minutes). The resulting weights were recorded and the data was graphed. We then could draw conclusions on the lab.
One dialysis tube was submerged in each beaker. Osmosis was allowed to occur for 5 minutes and then all of the tubes were removed from the water. The tubes were dried off and measured on the triple beam scale. The mass was taken and recorded for all three tubes. I then placed the tubes back into their respective solutions. The process was repeated four times for each tube in 5 minute increments, and then the materials were disposed of. The rate of diffusion of water in each solution was
In this experiment, I attempted to demonstrate the natural process of osmosis in life. To do so, five bags with semi permeable membranes containing different concentrations of sucrose or water were soaked in water or sucrose and their weight was measured at different time intervals. To minimize errors, I calculated the averages for each bag at each time interval for all the groups and observed that Bags 2, 3, and 4 which contained various concentrations of sucrose had a significant average net weight increase over time. While bag 5 that contained tap water and was soaked in a high concentration of sucrose, showed a substantial average net weight decrease. Both of these findings are due to the movement of water molecules across the semi permeable
Osmosis is the diffusion within water in which a semi-permeable membrane allows for a higher concentration solution to diffuse across said membrane into the lower concentration solution. Osmosis drives most biological processes allowing for equilibrium to be met and the transportation of molecules to occur (Nave, n.d.). However, larger biological molecules cannot pass through semipermeable membranes such as sucrose and starch (“GCSE Biology…”, n.d.). Within this experiment, the percent change of weight must be calculated to be able to quantitatively define the concentration movement of the molecules across the gradient.
The objective of this lab was to learn how to identify diffusion and osmosis, through selectively permeable membranes. Diffusion is the process in which particles move from an area of high concentration to an area of low concentration. When water enters or leaves a cell, it is called osmosis, which is the same process as diffusion, but solely focused on water. Certain membranes allow only particular chemicals to pass. These are called selectively permeable membranes.
In this study we constructed we researched whether different sucrose concentrations affect the rate of osmosis. In order to do this, we constructed artificial cells out of dialysis tubing filled with 20% sucrose and 40% sucrose and weighed them every 10 minutes for 90 minutes. In doing so, we concluded that the higher the sucrose concentration, the faster the rate of osmosis.
The purpose of this investigation lab is to observe osmosis of water into a cell, and also how. The goal of the experiment is to prove that a solution in an area of high concentration will move to an area of low concentration. In this experiment, we used sheep blood, 0.9% NaCl, 10% NaCl, and dH2O water to see what will cause when we add this to the cell. We will then record the rate of diffusion by measuring how did the blood flow into each solution and recording them. First, we placed with the wooden applicator stick, then dip the end into the blood and place tiny drop in the slide to observe what it will do.
The hypothesis that was stated prior to the lab was that the potato was going to be isotonic with the 0.1 solution. As seen from the data, the potato was isotonic with the 0.2 solution. This is because there was the least amount of weight change showing that the concentrations were isotonic and osmosis did not occur as much. As oppose to the concentration of 0.6 which caused weight percent to drastically decrease. This means that the two solutions were not equal and osmosis occurred and changed the initial weight of the potato.
INTRODUCTION: Osmosis is a type of diffusion where high concentrated water molecules move to lower concentrated water molecules through a selectively permeable membrane. Different concentrations affect the rate of osmosis. By increasing the amount of solvent in a solution, there will be lower water potential. If the water molecules inside of a cell has a higher concentration than outside, the water molecules would end up moving out of the cell.
One experiment was conducted for this lab report on osmosis and diffusion and how the concentrations effect a cell. The lab consisted of weighing 4 potato cylinders and putting them into 4 cups with different levels of sucrose solution. After incubating for two hours the potatoes were weighed again and the data was collected. The results showed two increasing, one staying the same, and one decreasing in mass. Osmosis is when water moves across cell membranes until both sides are balanced (Campbell 107).
Cells are important because they carry out all activities necessary for life. Cell structure can be examined and observed under a light microscope. The cell membrane is a critical component of the cell because it controls which materials pass through the cell. Osmosis, the movement of free water across the cell membrane, is demonstrated by examining the movement of material across the cell membrane of potato tissues. Potato tissues were put into various concentrations of NaCl to examine the effect of concentration on the potato tissues. Our hypothesis is if there is a higher concentration of NaCl, then the potato tissues will decrease in weight. In addition, the effect of concentration gradient and temperature on the rate of osmosis in an artificial system were investigated by using dialysis tubing. In this lab, the investigated variables were the change in temperature between 15°C and 55°C and the change in concentration of the NaCl solution. Our hypothesis is if there is a greater concentration gradient, then it will have a greater effect on the increased rate of osmosis compared to temperature. Determined was that as temperature and concentration gradient increased in solutions, the rate
Lab Objective: The purpose of this experiment is to test the membrane dynamics of different solutes when placed in unique solutions and the effect this has on diffusion rate, osmosis, and membrane permeability.
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 hypothesis states 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. In order to test the predictions of the hypotonic, hypertonic, and isotonic hypothesis for the solution made during the study, four samples of sucrose were taken and placed into two different beakers each containing a different concentration. Then dialysis tubing A was placed into beaker 1 with B, C, and D placed into beaker 2 for 45 minutes and weighted at 15 minute intervals. My finding in the study was that each of the four samples changed from their initial weight and for the most part accurately proved the hypothesis.