Biology Osmosis Lab Report Essay

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.

This experiment was used to examine the hypothesis that: Osmosis is dependent on the concentrations of the substances involved.

Will increasing the concentration of the same solution influence the rate of diffusion, was asked and hypothesized that the rate of diffusion will increase at higher concentrations. However, it is not believed that the higher concentrations will influence diffusion in a membrane that a solution can not fit through.

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

The control in the experiment is distilled water, as it does not contain sucrose 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.

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

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.

A major determinant of diffusion in a biological system is membrane permeability. Small, uncharged molecules pass through cellular membranes easily, while most and/or charged molecules cannot pass through the membrane. The movement of water across a selectively permeable membrane, like the plasma membrane

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 independent variable was the concentration of sucrose in the dialysis tubing we used as a simulated membrane.

This data was analyzed by calculating the cumulative change in weight for each dialysis bag. This was done from subtracting the weight of each bag from the initial weight of the bag. Doing so, allows the weight of each bag to be initially zero. For that, we must calculate the corrected cumulative change in weight. For each time interval of 10 minutes, we subtracted the change in weigh of bag #1 (tap water) from the weight of each bag at the specific time measure- this corrected any oscillations.

We filled bags of dialysis tubing with 20 ml of sucrose, NaCl, ovalbumin, and glucose and weighted them. After soaking them in distilled water for 10 minutes we measured them again. All of the bags gained water. Our hypothesis was that water will diffuse into the cells with ovalbumin, NaCl, glucose, and sucrose, but not the bag with distilled water. The independent variables were the different solutes in the dialysis tubing. The dependent variable was if the water would diffuse into the

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.

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.