Diffusion Lab Report

Certain substances are able to diffuse across plasma membranes under the right conditions through selective permeability. The selection of these certain substances allows for cells to maintain homeostasis, as these substances move from higher concentration to lower concentration. The purpose of this experiment is to see whether or not Lugol’s will be able to diffuse across dialysis tubing, which acts as a membrane. Lugol’s turns black when it interacts with starch, which will make the diffusion easy to see. This is all based off of a caterpillar eating a plant. The starch present in the leaves causes the caterpillar to produce amylase, which breaks down starch. In one experiment, the tubing will contain starch and amylase, while the other tubing

The materials used in this lab were, two glass beakers, four dialysis membranes: 20 (MWCO), 50 (MWCO), 100 (MWCO), and 200 (MWCO), a membrane holder, a membrane barrier, four solutes: NaCl, Urea, Albumin, and Glucose, a solution dispenser, deionized water, a timer, and a beaker flush. The four dialysis membranes are placed between the beakers and during each trial, certain concentrations are increased by adding one of the four solutes in the left beaker. Deionized water is added to the right beaker and replaced before the next test. A timer is adjusted to 60 minutes and the barrier between the beaker descends, allowing the solutions in each beaker to have access to the dialysis membrane separating them. The concentration is checked at the end of the 60-minute period indicating diffusing from the left to right or vice versa. If diffusion occurs in the experiment, repeat with the same membrane and change the concentrations. If no diffusion occurred, continue to the next sized membrane.

After weighing dialysis tubing of starch/sodium sulfate and adding the solution to two test tubes, the tubing was placed in a beaker containing a solution of albumin and glucose. Next, 1.0 mL of albumin and glucose were then placed in two test tubes labeled solution start. The tubing in the albumin/glucose solution was kept inside the solution for 75 minutes. Every 15 minutes the solution and tube was mixed (Keith et al., 2010).

First, we estimated the osmolarity of potato tuber cells by measuring the change in the potato’s’ weight after they were incubated in various concentrations of sucrose solutions (0.1, 0.2, 0.3, 0.4, 0.5, 0.6 M). First, we obtained 100mL of distilled water, and 100mL of each sucrose solution-which we placed in separate 250mL beakers. We then used a cork borer to extract 7 cylinders of potato. We then cut them all to about 5 cm long, and removed the skin from the ends. We placed all seven potato samples in a covered petri dish so they would not dry out. For consistency, we assigned each person their own, separate task to perform to each potato cylinder. First, one person removed the potato cylinder from the petri dish and used a paper towel to blot. Then

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.

Diffusion and osmosis happens in everyones everyday way of living, this can include when you spray your deodorant before school in the bathroom to then find going into the next room your still chocking on the dry smell of the deodorant this is diffusion when the particles in the air move from one place to another. Other example is when you go to have a bath, you fill the water put a bath bomb in the water and go get your towel and clothes when you get the bath bomb is gone but some little piece may be left over this is Osmosis this happens when two different concentrated solutions are separated then the solvent will then diffuse by the membrane from the less concentrated solution over to the more concentrated solution,

The Diffusion and Osmosis Lab determines the molarities of various sucrose solutions based on change in mass. Using table sugar in different amount of molar concentration 0.0M, 0.2M, 0.4M, 0.6M, 0.8M and 1.0M. The molarity of the solution of the sucrose solution in the dialysis tubing determines the amount of water that either move into the bag or out the bag, which also means its mass changed.

1. The relationship between rate of diffusion/ osmosis, volume, and surface area can be easily seen and analyzed through the data that was collected from procedure one: Surface Area and Cell Size. Phenolphthalein is a dye-material in this lab that was used to determine whether a substance was an acid or base. This could be told as the phenolphthalein changed into a murky. Muddled and clouded color when mixed with acids. When the chemical aid was mixed in with a base, the color

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.

The main purpose of this lab was to view the process of diffusion. This was to see how a caterpillar digests its food and what exactly happens in the process in regards to amylase, glucose, etc.

The purpose of this experiment was to test diffusion of molecules across the cell membrane to see which factor of time, concentration, and mass took effect of increase or decrease of diffusion over time.

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.

More specifically for the experiment we will need four deshelled eggs, four beakers and distilled water with a certain percentage of sucrose, a timer, and a scale to weigh the eggs. Using the process of osmosis, we will determine the weight of the eggs after being soaked in the solution. The four beakers each had distilled water in them with sucrose but all contained different amounts. One beaker contained 0% sucrose. The other beakers contained 10%, 40%, and an “unknown” amount of sucrose. Before placing the eggs into the solution, we are to weigh each egg separately to the nearest 0.1g and record this in table. Once that step has been completed, we then place one egg in each of the beakers separately that was marked with the amounts of sucrose. At fifteen-minute intervals, remove the deshelled egg from the water inside the beaker and wipe off all the excess water. After that process has been completed, we will weigh each egg separately to see if they have gained or lost their mass/weight. Once each egg has been weighed accurately, the recorded data is placed in the table provided. This step goes on for an hour. The deshelled eggs in this experiment will increase in mass in the different types of distilled water. This lab session provided the class with the evidence that diffusion and osmosis occurs within the different types of solutions.

Title Osmosis : How Water Diffuses Introduction The plasma membrane, the outside barrier of the cell is selectively permeable, allowing certain substances to cross more easily than others. When a cell is put in a solution, passive transport, diffusion, and osmosis occurs. During passive transport, diffusion of a substance takes place across a membrane without energy contribution, because of diffusion, the tendency for molecules to spread out. Net movement allows substances to move in one direction.

Cells are always in motion, energy of motion known as kinetic energy. This kinetic energy causes the membranes in motion to bump into each other, causing the membranes to move in another direction – a direction from a higher concentration of the solution to a lower one. Membranes moving around leads to diffusion and osmosis. Diffusion is the random movement of molecules from an area of higher concentration to an area of lower concentration, until they are equally distributed (Mader & Windelspecht, 2012, p. 50). Cells have a plasma membrane that separates the internal cell from the exterior environment. The plasma membrane is selectively permeable which allows certain solvents to pass through