Introduction Fick’s Law is used to measure the rate of diffusion. Diffusion is the movement of molecules from a region of high concentration to low concentration (Smith, 2012). Diffusion is highly important to almost every living organism. With the aid of diffusion various substances are able to passively move through an organism (Anderson et al., 2012). This process of transporting materials throughout the body can occur without the organism having to expend much energy (Anderson et al., 2012). An example of diffusion would be when a human consumes a glass of water; it will be diffused into the blood stream quite rapidly without our bodies putting in any extra effort. Diffusion plays a big role for mammals in their lungs and the intake …show more content…
First a Fisher Brand Dialysis cellulose acetate membrane tubing (#21-152-14), 12,000-14,000 MWCO (molecular weight cut off), was pre-soaked in distilled water for 20 minutes prior to use, as the barrier between concentration one and concentration two. A grey plastic collar was inserted into the tubing (with the aid of distilled water). It was very important to insert the collar far enough to ensure the tubing completely covers it. A red rubber septum was then placed into the opening and folding the septum back over the collar created a tight …show more content…
The ½ concentration however begins to plateau at a faster rate then the full concentration, which takes a much longer period of time to reach its plateau (fig.1). The plateau for both of the different iodine concentration concludes that each system is reaching equilibrium and therefore returning to a homeostatic state. Fick’s Law can be used to better understand the patterns in figure 1. It states that the diffusion rate is equal to the difference in concentration. This means that because the difference in concentration between the two solutions (iodine and soluble starch) used in this experiment were greater when the iodine was at full concentration, the rate of diffusion would also be greater. This occurs as the molecules of the iodine want to go from a place of high concentration to that of low concentration therefore the change in absorbance will be larger as more molecules of are passing through the semi-permeable membrane. We can thus conclude that when the iodine solution is at a higher concentration it will have a higher average absorbance as a greater amount of iodine molecules are needed to pass through the membrane to become saturated and return the system to equilibrium (Fig.
For the lab experiment of mixing the diffusion and exposure solution, we are going to test if the pigment is released in the exposure solution. We used materials as follows: Obtaining a beet, we punched out 2 cm long beets using a cork borer. Then we wash the beets in running water, after that we prepared 10 test tubes each containing different pH solution.
Diffusion and osmosis are necessary for the efficient transport of substances in and out of living cells. Diffusion is the most common and effective transportation process between cells and their surroundings, the movement of a substance along a concentration gradient from high to low, allowing essential nutrients and compounds to be transported without expending energy. Osmosis is a special kind of diffusion, specific to water. In order to observe diffusion and osmosis in real and artificial cells, a series of experiments was put together to observe how the surface area to volume ratio effects the rates of diffusion by using agar in different shapes with different ratios, next the rate of diffusion due to tonicity was observed using different solutions with different tonicities. And lastly live plant cells were submerged in different solutions with varying water potentials to observe how was potential effects the rate of osmosis and diffusion. It was concluded that the larger surface area to volume ratio, the faster rate of diffusion, the hypertonic solutions caused water to leave a cell and the hypotonic solutions allowed water to enter a cell, and that water potential will move from high to low in an attempt to maintain equilibrium.
The purpose of the Tonicity lab was to help identify the effects of an isotonic, hypertonic, and hypotonic solution to a slice of potato. The difference between diffusion and osmosis is that diffusion is the movement of particles or molecules from a region of higher concentration to a region of a lower concentration. While osmosis consists of the movement of water molecules through a semipermeable from a region of high water concentration to the region of less water concentration (Major Differences). Tonicity is the ability of a solution to ?alter the internal water volume of a cell? (Difference Between Solution, 2013). An isotonic solution should keep their normal shape; the osmotic pressure outside the cell has the same pressure within the cell. A hypotonic solution, are more dilute and contain a lower concentration of nonpenetrating solutes than cells. In contrast, a hypertonic solution have a higher concentration of
Specifically for the lab discussed we were to determine whether sucrose of RO H20 was of higher or lower concentration. We were able to determine permeable membranes were depending on the concentration of the solution or solvent. In this case we learned that solution and solvents of lower concentration allow for greater flow through the semi-permeable membrane, which supports the idea of diffusion. We learned that sucrose solution allowed for greater diffusion than RO H20. Also chloride ions and aluminum allowed for diffusion whereas starch and sulfate ions did not. We also learned Elodea in NaCl solution underwent a process called plasmolysis where the cells
Osmosis and Diffusion Investigation Aim: To examine the process of osmosis and diffusion. Part A: Step 1: Q1.[IMAGE] Q2. The jiggling motion is visible because the fat globules are constantly being bombarded by smaller particles. [IMAGE] Q3.
The Effect of Solute Concentration on the Rate of Osmosis Aim: To test and observe how the concentration gradient between a potato and water & sugar solution will affect the rate of osmosis. Introduction: Osmosis is defined as, diffusion, or net movement, of free water molecules from high to low concentration through a semi-permeable membrane. When a substance, such as sugar (which we will be using in the experiment we are about to analyse), dissolves in water, it attracts free water molecules to itself, and in doing so, stops them from moving freely. The effect of this, is that the concentration of (free) water molecules in that environment goes down. There are less free water molecules, and therefore less water molecules to pass across a semi-permeable membrane, through which sugar molecules and other molecules attached to them are too big to diffuse across with ease.
Diffusion is when substances diffuse from areas with many particles of the substance and areas with fewer particles of the substance. Concentration is the amount of substance in an area, which means diffusion is when substances diffus...
Analyze each fraction by spotting 10 times with capillary tubes on a TLC plate, which is exposed to iodine vapor for 15 minutes.
The Importance of Diffusion to Living Organisms Diffusion is basically the movement of chemical species (ions or molecules) under the influence of concentration difference. The species will move from the high concentration area to the low concentration area till the concentration is consistent in the whole system. Diffusion mostly occurs in gases and liquids as these can move freely. The main features of an efficient diffusion system would be that it has a large surface area, thin membrane and a continuous supply of substances. A large surface area is needed so that high amount of substances can be exchanged at a time while the thin membrane means that the diffusion pathway would be short so that it is more efficient.
Dialysis tubing is made from regenerated cellulose or cellophane, and is used in clinical circumstances to ensure that molecule have a filtered flow, and that larger solute molecules do not enter the dialysis tubing (Alberts, 2002). Like a cell membrane, dialysis tubing has a semi-permeable membrane, which allows small molecule to permeate through the membrane. Thus, the dialysis tubing mimics the diffusion and osmosis processes of the cell membrane (Alberts, 2002). Although the dialysis tubing has a semi-permeable membrane, which mimics a cell, its structure is different. The me...
The purpose of this experiment is to investigate the effect of changing the concentration of sodium chloride solution on the rate of osmosis in tubes of potatoes. This was maintained using equal measurements of the potato tubes and applying them into the different concentrations of sodium chloride, 0%, 2%, 5%, 10%, 20% and 26%, in beakers then measuring the change in mass of the potato tubes afterwards. The time taken for all potato tubes to be placed in solution was 15 minutes. Can the concentration gradient of the sodium chloride solution influence on the rate of osmotic diffusion undergone by the potato tubes?
Now, assemble and arrange all of the needed supplies so that they are easily accessible. Connect the IV tubing to the solution bag and allow the fluid in the bag to run through the entire length of the tubing, also known as priming the tubing. When this is done, clamp the tubing closed. You will then need to tear several pieces of tape, six to eight inche...
when to do it etc. This should lead me to good results at the end of
The purpose of this lab was to see firsthand the diffusion of a substance across a selectively permeable membrane. Diffusion is the movement of molecules from an area of high concentration to an area of lower concentration until both concentrations are equal, or as you could more professionally call it, equilibrium. This concept is one that we have been studying in depth currently in Biology class.
The overall purpose of the experiments in this lab was to introduce the function and structure of the plasma membrane, describe the workings of diffusion and osmosis, and to demonstrate how different factors such as particle size, temperature, and space of diffusion area affect the rate of diffusion. With the results from the experiments, it can be concluded that all of the factors listed do affect diffusion, and there may be many more than are unaccounted for.