Diffusion Lab

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?

1. Understand the importance of diffusion to cellular metabolism and the how it constraints the evolution of cell/body size and shape

In this lab we found out that the dialysis bag contained more fluids inside it. This can happen because sucrose is small enough to pass through the selectively permeable membrane. Some errors that might have been encountered during the lab could have been the fact that some of the dialysis bags were not tightly tied with the dental floss, or that the wrong substance was used. Another possible source of error was if the carrot strips had been dehydrated from the beginning of the experiment or were already

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 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.

Diffusion is the movement of molecules from a region of higher concentration to a region of lower concentration. The rate at which molecules diffuse can be determined by the relationship of molecular weight and that rate of diffusion through a membrane. Hypothesis of this experiment is that the fluid with higher molecular weight will diffuse at a slower rate and distance.

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.

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

Diffusion Lab James D. Motley Biology Lab B Period 2 Uma V. CECP ABSTRACT: In this lab I used water, agar cubes, a beaker and a scale to see whether diffusion increased or decreased the volume of the agar cubes. I let the cubes sit in water overnight, then weighed them to see if the volume changed. In conclusion, the volume increased, because of the water soaking into the cubes.

Iodine is able to pass through a membrane but starch cannot. From the video “Science Experiment diffusion through a membrane”, we observed the starch turning dark blue after being placed in the iodine solution. This means if the starch and iodine are placed together, separated by a selectively permeable membrane, the iodine will diffuse, a type of passive transport, through the membrane into the starch but not the other way around. This happens because the membrane is selectively permeable, meaning only certain molecules and objects are able to pass through. Since the iodine molecules are smaller than the starch, the iodine is able to diffuse through, while the starch molecules are too big to. We can see that size is the reason why iodine

Investigation 2: The question that was trying to be answered was what affects the rate and direction of diffusion in a system. The question was asked in order to determine what substances would take in water through their selectively permeable membrane of the dialysis tubing rather than let out their substance. This experiment demonstrated how different solutions act with water and whether or not they are hypotonic, isotonic, or hypertonic.

this unexpected finding, supported by an analysis of the role of density in the ability of cells to communicate