...Sonora Schueneman Dr. Kemp- Hailee Nerber Bio 111- 551 19 September 2017 Osmosis and Diffusion Across a Plasma Membrane-Lab 2 Week two in the lab consisted observing a constructed experiment involving osmosis and diffusion across a semi-permeable membrane. This allowed myself to formulate a hypothesis stating, the four pipets of cooked starch and amylase will diffuse through their dialysis bag into the beaker containing 2/3 water and four pipets of Lugol’s solution. Thus being stated, the null hypothesis would be, the four pipets of cooked starch and amylase will not diffuse through their dialysis bag into the beaker containing 2/3 water and four pipets of Lugol’s solution. In order to test our hypothesis, I set up a control beaker (Beaker...
Words: 476 - Pages: 2
...In today’s lab we were able to get a hands on look at the osmosis and diffusion process as well as analysis the nutrients in food. We were separated into groups chosen by the Teachers Assistant and began our lab. There was a brief lecture with notes and what we would be looking forward to within the lab. We were given more information on what osmosis and diffusion were. Further into the discussion we learned about controls and variables. As we finally began the experiment we needed to make sure we had the required items such as the beakers, testing strips and the chemical solutions. From there we were able to go over the instructions and carefully do the assigned tasks. For our first experiment which was the Osmosis and Diffusion lab. We needed...
Words: 451 - Pages: 2
...**IF YOU ARE USING THIS** please note that this was an experiment conducted by me and my lab partner. Due to the fact that she wrote the materials/methods section and the abstract, I have not included it. This is only results and analysis for a diffusion lab for a Biology400 college class. Please do not copy and paste, it is PLAGIARISM. Only use for clarification of analyzed results. Results Figure 1a. The following table includes the circumference of the circle that was created by the diffusion of three separate dyes. It also includes their molecular weight. The chart shows that Potassium Chromate diffused much more than the Methylene Blue and the Congo Red, both in the refrigerated gelatin and the room temperature gelatin. The Methylene Blue has the second lowest molecular weight, and diffused more than the Congo Red as well. The results also show that, with the exception of the Potassium Chromate, the dyes in the refrigerated gelatin diffused at a slower rate than those in the room temperature gelatin. Solute (Dye) Molecular Weight Room Temperature Distance (mm) Refrigeration Distance (mm) Potassium Chromate 194 18 19 Methylene Blue 374 15 10 Congo Red 697 12 11 Figure 1b. The image below is a photo of the gelatin plates an hour after they were dyed. The plate on the left was placed in the refrigerator, while the plate on the right remained at room temperature. Figure 2. The table below illustrates the rate of osmosis for each of four different combinations...
Words: 971 - Pages: 4
...Diffusion And Osmosis Introduction: There are several valuable aspects of this lab that must be understood before it is conducted. The first of these concepts is called diffusion. Molecules are constantly moving and as they are moving they tend to move from areas of higher concentration to areas of lower concentration. Diffusion can be defined as the net movement of molecules from higher to lower concentrations. One example, of diffusion is when an item like perfume is opened in a room. Shortly after it is opened the smell can be detected throughout the entire room. Diffusion can occur through a membrane such as that of a cell which explains how something can enter the cell. One special type of diffusion is called osmosis or the diffusion of water. Osmosis describes how water moves through a membrane from areas that have high water potential to areas that have lower potential. Water potential is defined as the measure of free energy of water in a solution. Biologists use this term to help describe why water moves from one area to another. Water potential can be affected by two major aspects pressure and the amount of solute. Water potential can be calculate by the pressure potential added to the solute potential. In order to calculate the solute potential one must multiply the ionization constant, the molar concentration, the pressure constant, and the temperature. When looking at a solution one can categorize it into several different relationships based...
Words: 3633 - Pages: 15
...The purpose of this experiment was to demonstrate how diffusion and osmosis moves across a dialysis membrane. The sub-purpose was to determine if the sucrose solution, that was in dialysis tubing would leak into the distilled water. The hypothesis states that if a sucrose solution, in dialysis tubing, is placed into a beaker filled with distilled water the net movement of sucrose will be into or out of the dialysis bag. The null hypothesis states that if the sucrose solution in a dialysis bags mass may change after taking it out of the water each time to be weighted between each 15-minute increment 5 different times. After 15, 30, 45 and 60 minutes it can be concluded that weighing the sucrose solution in the dialysis bag increased in weight after each increment. Keywords: Diffusion, Osmosis, Dialysis bag, Sucrose solution, Distilled water Introduction...
Words: 1136 - Pages: 5
...Atichai Suwannapeng Pre Lab #6 Diffusion, Osmosis, and Tonicity Group #3 Section A3 Group Members: Laghu Shakya, Alex Maican, Kelvin Chen, Ziye Lin 10/18/2015 Abstract: In this lab we will be gaining an understanding of how transport in membranes work. This is important because in our semi permeable cell membrane the mode of movement relies on transport. Some methods of transportation for molecules are simple diffusion, facilitated diffusion, active transport, exocytosis and osmosis. The reason molecules tend to move around when dissolved in a solution is because all molecules display random thermal motion and have kinetic energy. Kinetic energy is what allows the molecules to diffuse down a gradient of high concentration to regions of low concentration until the distribution of molecules become equal and achieved dynamic equilibrium. The entire solution only becomes homogeneous when one of the several factors are reached: the size of the dye molecules, temperature of the solution, density of the solvent and concentration of the dye. Heat is what causes random motion of molecules and passively moves molecules in biological systems. However, we can’t see this movement with our naked eye. In order for us to see this movement, we must use a microscope to see the small particles move after collision, this is called the Brownian movement. When talking about the cell membrane we must understand that it is selectively permeable, which means it can choose what can pass through...
Words: 1835 - Pages: 8
...Solute Concentration of Potatoes Carmen Chen Blk: 7 December 14, 2013 Purpose: to determine the concentration of solute in potatoes cytoplasm. Materials and Equipment: refer to the lab sheet. Observations: | |Concentration of sucrose|Initial mass |Final mass |Percentage change in | |Test tube # |solution ( |(g) |(g) |mass | | |mol/L) | | |(%) | |1 |1.0 |3.0 |-0.9 |-30% | |2 |0.9 |3.9 |-1.2 |-30.8 % | |3 |0.8 |3.2 |-0.7 |-21.9% | |4 |0.7 |3.5 |-0.8 |-22.9% | |5 |0.6 |3.3 |-0.6 |-18.2% | |6 |0.5 |3.0 |-0.3 |-1% | |7 |0.4 |3.1 |-0.2 ...
Words: 1426 - Pages: 6
...Clara Skepple Miranda Wilby, Sarah Cavanagh Thursday, March 3 2016 Observing Diffusion and Osmosis INTRODUCTION: Related Theory: The cell membrane is the outermost boundary of the cell, made up of proteins and lipids. This membrane holds the cell together and establishes the movement of materials that go into and out of the cell. This is a selectively permeable membrane: a barrier that allows some molecules to pass through, but prevents other molecules from penetrating (1). Passive transport is the movement of materials across a cell membrane without the use of energy from the cell. One type of passive transport is diffusion. Diffusion involves the movement of molecules from an area with a higher concentration to one with a lower concentration (1). Diffusion is affected by many things; temperature, concentration and pressure. It disperses until molecules are equally distributed within a space. Osmosis is diffusion of water through a selectively permeable membrane. Water will diffuse from the place with higher concentration to the place with a lower concentration. Water goes through the concentration gradient. Which is when molecules without energy diffuse from the place with higher concentration to the one with lower (1). The ability to diffuse through water all depends on the size of the molecule as well. For example, starch is a large molecule therefor it should not fit through the cells membrane. Starch is a polysaccharide because it is comprised of lots of sugars. Individually...
Words: 1656 - Pages: 7
...Diffusion and Osmosis: A Full Analysis on the Concentration of Solutes and the Molecular Weight of Substances in a Dialysis Tubing and Potato Experiment Alejandro Gonzalez October 30, 2012 Biology 1500 Professor Raja Abstract The purpose of the diffusion and osmosis lab experiments is to determine the contents present before and after leaving a dialysis tubing in a beaker of solution and to test water potential by determining the percent change in mass of potatoes when left in different concentrations of sucrose in numerous beakers. In the first experiment, what occurred was that we put contents into the dialysis tubing and in a solution in a beaker and we were to set the tubing in the beaker for a set amount of time and see what contents are present in the beaker and in the dialysis after the amount of time. In the second experiment, we were to test if a mass change would occur if we set potatoes in different concentrations of sucrose. My alternate hypothesis in the first experiment with the dialysis tubing was accepted due to the fact that glucose and sodium sulfate diffused across the pores of the tubing, but starch and protein could not be. My alternate hypothesis in the second experiment was also accepted due to the fact that there was a mass change in the potatoes when put in different concentrations of glucose. Introduction Diffusion and osmosis are two terms that actually coincide with each other in the big picture and in this particular set of experiments...
Words: 2729 - Pages: 11
...AT THE CELLULAR LEVEL:- Glucose is a hydrophilic molecule and, as such, cannot diffuse across cell membranes. The two families of glucose transporters are the sodium-glucose contransporters (SGLTs) and the facilitated-diffusion GLUT transporters. SGLTs are localized in the apical membranes of simple epithelia (intestine and proximal tubules of the kidney) and are involved in the transepithelial transport of glucose. GLUTs provide for sodium-independent transmembrane transport of glucose by facilitated diffusion. GLUT1 and GLUT3 are widely expressed and are high-affinity, low-capacity transporters. These GLUT isoforms are linked to high-affinity hexokinases. Hexokinases phosphorylate glucose to form glucose-6-phosphate (G6P). Because G6P does not bind to GLUTs, G^P cannot leave the cell. Consequently, the hexokinase reaction commits glucose to metabolic pathway. GLUT2 is a low-affinity, high-capacity isoform expressed in the liver, pancreatic islet beta cell, and basolateral side of intestinal and renal tubule cells. In the liver and beta cells, GLUT2...
Words: 562 - Pages: 3
...Introduction Osmosis is a key for every living organism on Earth, from humans to plants. In this lab we examined the processes of osmosis and diffusion. Osmosis is a specialized type of diffusion; “it is the process of water moving across a semi-permeable membrane, in response to a concentration gradient” (Readel, 2000). Fluid passes both in and out of the semi permeable membrane in osmosis, but usually there is a “net flow in one direction or another, depending on which side of the membrane has a higher concentration of solutes” (Smith, 2013). There are different factors that can affect the rate of osmosis such as temperature. In one experiment, my group and I used dialysis tubing to simulate a cell membrane. This tubing was filled with molasses and was immersed in water; cold, warm and hot. The bags were removed at regular intervals and measured for the amount of osmosis that occurred. We observed that the bags in the hot water experienced the highest amount of osmosis. In warmer temperatures the water particles tend to diffuse from high to low concentration, thus trying to dilute the solute concentration from the solution outside. From these observations and conclusion, my group and I hypothesized for our own experiment the level of solute concentration will affect the rate of osmosis. Diffusion is the process of “any substance moving from a region of high concentration to a region of lower concentration” (Readel, 2000). Therefore we predicted that the higher concentration...
Words: 1054 - Pages: 5
...Lab Report on Osmosis and Diffusion Biology 1, Period 3 March 15, 2010 Lab Team: Jason Perez, Kicia Long, Chris McLemore Purpose: The purpose of this lab is to observe the acts of passive transport: diffusion and osmosis in a model membrane system. The experiment will show how molecules in solution move from areas of higher concentration to areas of lower concentration. The model membrane is dialysis tubing. Materials Used 2.5 cm dialysis tubing 15% glucose solution glucose test strip 1% starch solution distilled water Lugol’s iodine solution Procedure: Each member of the lab group will complete the procedures independently 1. Obtain a 30 cm piece of 2.5-cm dialysis tubing that has been soaking in water. Tie off one end of the tubing to form a bag. To open the other end of the bag, rub the end between your fingers until the edges separate. 2. Place 15 mL of the 15% glucose/1% starch solution in the bag. Tie off the other end of the bag, leaving sufficient space for the expansion of the contents in the bag. Record the color of the solution and weight of the bag in a data table. 3. Test the 15% glucose/1% starch solution for the presence of glucose using a test strip. Record the results in the data table. 4. Fill a 250 mL beaker or cup two-thirds full with distilled water. Add approximately 4 mL of Lugol's solution to the distilled water and record the color of the solution in data table. Test this solution...
Words: 750 - Pages: 3
...Marisa M Souza AP Biology Mrs.Therrien October, 6, 2015 Diffusion and Osmosis Exercise 1A: Diffusion In our diffusion experiment glucose is leaving the bag and Iodine-Potassium-Iodide or IKI is entering the bag. The change in color within the bag indicates the presence of glucose. The IKI moved from the beaker into the dialysis bag, this resulted in a change of color to black within the bag. This made the concentration within the bag equal to the concentration outside the bag. The glucose solution moved out of the bag making glucose present in the beaker. The glucose moved to make the solute concentration inside and out equal. If the initial and final % concentration of glucose and IKI for in the bag and in the beaker were given they...
Words: 1292 - Pages: 6
...Diffusion and Osmosis Diffusion is the passive movement of molecules or particles along a concentration gradient, or from regions of higher to regions of lower concentration. Osmosis is a type of diffusion. This is the diffusion of water through a selectively permeable membrane (chooses what comes in and what goes out) from a region of higher water potential to a region of lower water potential. Water potential is the measure of free energy of water in a solution. Unlike diffusion, osmosis requires ATP to move the particles across the membrane. Hypothesis: In both experiments diffusion and osmosis will occur between the solutions. In experiment 1A the tube of glucose/starch will absorb the iodine solution in the cup. In experiment 1B the tube of distilled water will lose weight, and the tube of glucose will gain weight. The purpose of the experiments is to differentiate which test was diffusion and which was osmosis. Materials: Experiment 1A: Plastic Cup, Plastic Pipet, Iodine-Potassium Iodide, Deionized Water, Glucose Paper Strip Experiment 1B: (3) 15 cm pieces of Dialysis Tubing, beaker, 15 cm piece of white thread, 80% Glucose, 2% Starch, Plastic cup, 10% glucose, 15 cm blue thread, distilled water, 15 cm red thread, 20% glucose Procedure Experiment 1A: First cut a 15-cm length of dialysis tubing. Place the dialysis tubing in a beaker of distilled water and allow it to remain in the beaker for 1 minute. Open the dialysis tube by rolling it in between thumb...
Words: 1249 - Pages: 5
...In our lab, we were able to witness the process of osmosis and diffusion through dialysis tubing, starch, glucose, iodine, and water. The reason we chose to use these materials is because the dialysis tubing could act as a selective permeable cell membrane to view which molecules are able to pass through and which weren’t. We used the starch, since it is a polymer, and found out that it could not pass though the membrane. We used the glucose, which is a monomer, and found that it was easily able to go into a state of equilibrium with the water. The monomer was able to pass through the dialysis tubing due to its small size and the polymer was not due to its large size. This was what we had predicted in our hypothesis except for the fact that although the glucose did pass through the membrane it did not completely pass through only some of it to create equilibrium. In the starch and iodine solution it was the iodine which was allowed to pass thought the starch was not able to due to its large size further explaining why the water had eventually turned almost clear again compared to its brown looking initial state and the inside of the membrane had turned almost completely blue compared to the clear color it was before. When measuring the glucose both inside and out of the membrane we found that they both had some glucose in it, and although we could not visibly see the changes, it was noticed that the diffusion had occurred and since there was some glucose in each it is safe to...
Words: 1201 - Pages: 5
