Diffusion Investigation

Cells and molecules in the environment are constantly moving and changing, for cells to function properly there is a need for equilibrium to be met. The size of the cell and the solution outside of the cell affects the rate of diffusion and osmosis in the cell. Cells are constantly trying to reach an equilibrium with the molecules and substances around it, which is why there are such terms as: hypertonic, hypotonic and isotonic. The procedures allowed testing of whether or not surface area or volume increased diffusion and how different substance control diffusion. Cells are constantly moving to reach equilibrium through diffusion and osmosis.

If the solution in the left beaker contained both urea and albumin, which membrane(s) could you choose to selectively remove the urea from the solution in the left beaker? How would you carry out this experiment?

Aim: To plan and carry out an investigation to show the relationship between volume/Cm3, surface area, and diffusion using agar cubes measured in time/s; and to demonstrate, using diffusion, why the size of cells is limited, keeping the room temperature and pressure constant.

In performing the proper experimentation, we poured some of the methylene blue substrate in a piece of paper, for ease transport towards the agar plates. We performed it cautiously by not inhaling it, for it is a form of powder. We carefully place the substrate at the center of the agar plates, to ensure that is that there is enough space for diffusion to take place. After the moment we placed the substrate, we carefully placed a transparent ruler under the plate to measure the diameter of the substrate in 0 minutes. We carefully note the time, having a 15-minute interval and record the changes in the diameter of the substrate. We continued it, until we have an hour observation.

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 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.

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 objective of this experiment is to develop an understanding of the molecular basis of diffusion and osmosis and its physiological importance. Students will analyze how solute size and concentration affect diffusion across semi-permeable membranes and how these processes affect water potential. Students will also calculate water potential of plant cells.

Abstract: Cell membranes play an important role in regulating what goes in and out of the cell. Diffusion, the process of movement of substances across the cell membrane from higher concentrations to areas of lower concentration, plays an active role in the transport and the regulation through cellular membrane. Sometimes, there are cases when cells are placed in hypotonic solutions and substances will diffuse through the cell membrane too much and will result the cell to hemolysis, causing it to swell and rupture. In this lab, we observed and recorded the time it took for diffusion of a propanol series substance to diffuse through a mixture of ovine blood to

The following hypothesis was made in regard to effect of the concentration gradient on the rate of diffusion: The higher the concentration gradient, the faster the rate of diffusion.

In order to assimilate diffusion through a permeable membrane potassium permanganate and methylene blue were used in experiment. The objective was to compare the rates at which the liquid compound of different molecular weight diffused through agar. This was achieved by obtaining agar in a petri dish with two wells to hold the liquid compounds. The rate was measured by time and diameter distance diffused. This process was observed for 60 minutes at 15 minute intervals.

In conclusion, the potato cube with the highest surface area to volume ratio (the 1x1x1 cube) had the fastest rate of diffusion as it had the largest percentage increase in mass. While all the other cubes of potato had larger increases in mass at face value compared to the smallest cube, the smallest cube had the largest overall gain in percentage. The results support my hypothesis that the smallest cube will have a higher rate of osmosis because it has a proportionally larger amount of surface area compared to its volume.

Diffusion is the transfer of molecules from an area that has a higher concentration to an area that has a lower concentration. Osmosis is the diffusion of water. The purpose of this experiment was to study the process of osmosis. In order to test osmosis, eggs that had been soaking in vinegar were taken and placed in four beakers of solution with different levels of glucose. Using this experiment we were able to determine the rate of osmosis of different solutions, with various amounts of glucose, through eggs. In the results of this lab it was found that the eggs were either hypertonic or hypotonic and that the

The next experiment was to test diffusion in agar solution. A petri dish with a layer of solidified agar had four holes punched in it using a No. 5 cork borer. Three holes were punched in a triangle shape with the fourth hole directly in the middle. There should be 15 mm between each outside hole and the middle hole. The three outside holes were filled with one drop each of potassium bromide, potassium Terri cyanide, and sodium chloride. The middle hole was filled with a drop of silver nitrate. It is very important to make sure that none of the holes overflow. After each has been filled allow to sit for an hour and observe the results.

Passive diffusion, also known as simple diffusion, is used to describe the exergonic reaction of a substance where the substance passes in the direction of the concentration gradient. Most of the molecules move from the area of high concentration, inside the membrane of a cell, to the outside where there is