Starch Lab

3. Of the substances that diffused through the bag, did all of the molecules diffuse out? About half of the glucose did diffuse through the bag.

The bags were put in their corresponding beakers, all of which contained tap water, except beaker #5 (tap water bag #5 was placed in beaker #5 which instead of holding water, was filled with 40% sucrose) concurrently, recording the time. In the same manner in which the bags were placed in the beakers simultaneously, remove the bags every 10 minutes, and record the weight of each bag. This process should be repeated for at least 90 minutes total.

Bag 1 was 10 mL and filled with dH2O and submerged in dH2O, resulting in being isotonic solution. Bag 2 was 10mL and filled with 20% sucrose, which was submerged in dH2O, resulting in a hypertonic solution. Bag 3 was 10mL and filled with 40% sucrose and was then submerged in dH2O, resulting in a hypertonic solution. In the sac containing no sucrose, just dH2O, there was no net movement; it maintained its initial mass of 16g throughout the 45 minute experiment, meaning it had 0% mass change (see Table 1). Bag 2 was the sac containing 20% sucrose and its mass was increased throughout the experiment and its final total mass change percentage was 7% (see Table 1). The sac containing 40% sucrose had the greatest mass change over the forty-five minute time period (see Table 1). The results in Table 1, coincide with the Graph 1. The sac filled with 0% sucrose had no mass change, therefore has 0 as its rate of osmosis (Graph 1). The sac with 20% sucrose had a rate of osmosis of 0.027g/min, making it the second biggest rate of osmosis. The sac containing the 40% sucrose had the largest rate of osmosis, being 0.098g/min (Graph 1). A table was added to fully understand rate of osmosis (refer back to Graph

The dialysis bag experiment resulted with beaker one having relatively similar numbers, showing as an isotonic medium. Beaker two’s solution gradually increased within an hour which caused the product to

Part A: How does the molarity of sucrose solution inside dialysis tubes affect the percent change in mass of the tube after 20 minutes?

If the hypothesis is correct, the masses after we place the tubing samples in water will be higher than the masses before. We will see the greatest % increase in mass in the highest concentration of sucrose (1.0 M). The % increase will get lower as concentration decreases. All of the samples should have some increase in mass because we are placing them in distilled water. Based on the known solutions, the data should yield a mathematical model relating concentration and % increase, which we can use to find the concentration of the unknown solution.

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

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.

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. Beaker 1 is  250- mL and contained 150-mL of 10% sucrose with dialysis tubing A, while beaker 2 (a large bowl) contained 1% sucrose, with dialysis tubing  B, C, and D. Tubing A contained 10-mL with 1% sucrose. Tubing B

-The more dissolved oxygen in the water, the more fish is observed in that area of water.

There were several steps completed to prepare for the experiment. Three dialysis tubes were filled with approximately the same volume of distilled water and then were tied shut. The initial mass (in grams) of the tubes was taken using a triple beam scale. I then filled three 500 mL beakers with 400 mL of water each and dissolved different masses of solute (table sugar) in each beaker in order to make 5%, 10%, and 20% solutions. The beakers were labeled accordingly, and then 20 g, 40 g, and 80 g (respectively) of table sugar was weighed out using a digital scale and placed into the corresponding beakers. The sugar was stirred in using a stirring rod until all of the solute was completely dissolved.

In this experiment osmosis is the main process taking place. Osmosis is the diffusion of water molecules of a solvent which pass through a semi permeable layer and in most cases are due to a concentration gradient meaning that the water molecules travel from an area of low concentration to one of higher concentration. In this investigation, gummy bears of different colours (dependent variable) were placed in different concentrations of glucose (independent variable) over a certain period of time.In addition to that, the color of the gummy bears was also observed to see if the color could

In the final experiment we filled a dialysis bag with starch solution and tied off both ends of the bag so that it is water tight. We then filled a separate bag with sodium chloride and submerge both dialysis bags in two beakers of distilled water. We allowed the bags to sit in the water for 10 minutes. We then put silver nitrate into the water that held the dialysis bag filled with sodium chloride and recorded any changes in the water. We then added iodine to the water that held the dialysis bag of starch and observed any changes in the water.

The conditions were 9mM albumin in the left beaker and 10mM glucose in the right beaker with the 200 MWCO membrane in place. Explain the results.

The beaker was then filled partially with distilled water; 1 ml of potassium iodide was then added, and the solution was tested for the presence of glucose. This data was recorded in table 1 on the data sheet along with the starting color of both the potassium iodide solution and the glucose/starch solution. The dialysis tubing was then submersed into the beaker containing the potassium iodide solution, and set aside for 30 minutes to allow maximum diffusion.