Biology 1020 Diffusion and Osmosis Lab Report

In: Science

Submitted By kaeskola
Words 873
Pages 4
Kristina Eskola
BL 1020
L01
Diffusion and Osmosis Lab Report (Dialysis)
Introduction:
Dialysis Tubing is a membrane made of regenerated cellulose fibers formed into a flat tube. If two solutions containing dissolved substances of different molecular weights are separated by this membrane, some substances may readily pass through the pores of the membrane, but others may be excluded.
We will be investigating the selective permeability of the tubing to reduce sugar, glucose, starch, and iodine potassium iodide. We will test this by placing a solution of glucose and starch into a dialysis tubing bag and then place this bag into a solution of iodine potassium iodide (I2KI).
Prediction: The I2KI solution will turn blue when adding Benedict’s reagent.
Hypothesis: The solution of water and I2KI will be the most permeable because they will mix and react with Benedict’s reagent and the heat so the cell membrane only allows certain molecules to enter and leave the cell
Materials and Methods: In the experiment we will be using two tests. In the first test, we will be using I2KI to test for the presence of starch. When I2KI is added to an unknown solution, the solution will turn purple or black if starch is present. If there is no starch in the solution, it will remain pale yellow. In the second test we will be using Benedict’s test for reducing sugar. When Benedict’s reagent is added to an unknown solution and the solution is heated, it will turn green, orange or orange-red if sugar is present. If no sugar is present in the solution, it will remain blue. The materials needed for this experiment are the 30% glucose substance, starch solution, I2KI solution, Benedict’s reagent, hot plate, 500 mL beaker with water, test tube holder, 3 test tubes, pipettes, 2 400 mL beakers, and a strip of moist dialysis tubing.
Procedure: The first thing we did was prepare the…...

Similar Documents

Diffusion and Osmosis

...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......

Words: 2729 - Pages: 11

Ap Biology Diffusion + Osmosis Lab

...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......

Words: 3633 - Pages: 15

Results/Analysis of Diffusion Lab

...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 of a solution in......

Words: 971 - Pages: 4

Osmosis and Diffusion

...Brad Sanford Bio 1120 Section 6 September 17, 2013 Partners: Dominique & Carleigh Lab #2: Osmosis & Diffusion Introduction Diffusion is the movement of molecules from a high concentration gradient to a low concentration gradient. This can occur in gases, liquids, and solids. Osmosis is a type of diffusion that allows water molecules to move through a semipermeable membrane freely by way of passive transport. During osmosis a semipermeable membrane will allow small water molecules to pass through freely without any help but larger molecules like proteins will not move through the semipermeable membrane without active transport. Active transport requires a chemical energy like ATP (adenosine triphosphate) to help the larger molecules move through the cell’s membrane.(Krane) When describing high and low concentrated solutions, it is useful to understand the terms hypertonic, hypotonic, and isotonic. A hypertonic solution has a higher concentration of solutes compared to a lower concentrated solution as water will move out of the solution (Dehydration). A hypotonic solution has a lower concentration of solutes compared to a solution with a higher concentration of solutes and water will move into the solution (Swelling). In a isotonic solution the solutes are at an equal concentration and there is no movement of the water. In this lab, two experiments were performed. The first one uses a small plastic bag closed up and filled with cornstarch and distilled......

Words: 1110 - Pages: 5

Biology Osmosis

...Temperature has a great effect on osmosis. Based on our data, the bags that contained water at 55 degrees Celsius had a much greater rate of osmosis than the bags at 15 degrees Celsius. When the environment is heated up, reactions occur at a much faster rate. This is because the extra heat provides more energy. Increasing the concentration also increases the rate of osmosis. This is because there is a lesser concentration of water inside the bag in the 40% rather than the 15%. The water will rush into the bag at a greater rate because of this. Our data shows that at both temperatures the bag that had 40% NaCl concentration added more water faster than the 15% concentration. Every experimental bag increased in weight, but they did not increase at the same rate. According to our data graph, the concentration of NaCl that would be isotonic to the contents of the potato cells would be around 0.30%. The only concentration that was hypotonic to the potato cells was the 0% concentration of NaCl, in which water rushed into the cell. The 0.50%, 1.0%, 2.0%, and the 3.0% were all hypertonic, because water left the potato cells due to the concentrations of NaCl. The turgor pressure was greatest in the 0% solution due to the outward push the extra water molecules put on the cell wall. The 3.0% solution had the least amount of turgor pressure, because more of the water already in the cells rushed out, leaving the cell wall not as rigid. In the 0.6% NaCl solution, the cells were more......

Words: 633 - Pages: 3

Biology Lab Report

...BIOL 1F90 Experiment #5 - Archaea: Characterization of Halophiles Student Name: Brittany Barnes Student Number: 5408224 Lab Section: 35 Date Experiment Performed: January 13, 2014 Lab Partners: Kayla Hutchinson Fallon Fersaud Ashley Maulucci Abstract Halobacterium salinarum and Haloferax volcanii come from the domain called Archaea and are considered to be halophilic, because they thrive in extreme environments. In this lab experiment, several tasks took place. In order to be able to observe the colony morphology of both Archaea, they were grown on an agar surface that allowed them to form colonies of characteristic colour and appearance. In order to observe the physiology of both Archaea on the effect of salt concentration, pH, and temperature, they needed to be placed on agar plates and incubated for two weeks. Being incubated for two weeks, allowed the halophilic archaeal cultures to grow. The objective of this experiment was to determine the morphological and biochemical characteristics along with the growth requirements of the halophilic Archaeans; Halobacterium salinarum NRC-1 and Haloferax volcanii DS2. Introduction The domain, Archaea, possesses prokaryotic cells and has a cell wall that contains no peptidoglycan. Archaea contain rRNA that is unique to the Archaea as indicated by the presence of molecular regions. Archaea usually live in extreme environments and include methanogens, extreme halophiles, and......

Words: 2636 - Pages: 11

Diffusion and Osmosis

...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......

Words: 1249 - Pages: 5

Osmosis Lab

...Effects on rate of Osmosis across a selectively permeable membrane for varying starch solute concentrations and water mixed with Lugol’s Iodine The contents of this document pertain to the effect of particle (starch) concentration on the rate of Osmosis through a selectively permeable membrane made visible by the use of Lugol’s Iodine indicator. The results proved that the greater the concentration of the starch solute within the membrane, the greater the rate of osmosis and change in color of the solute due to an increase of Lugol’s Iodine diffusing into the membrane and reacting with the starch. Ruba Nizam 3/18/2014 Introduction The purpose of this lab is to test the rates of osmosis on a model of a selectively permeable membrane filled with varying levels of starch concentrations using dialysis tubing. This experiment will make it possible to see how particles move from an area of high concentration to an area of low concentration due to the use of Lugol’s Iodine indicator. According to Michael McKinley, osmosis is defined as the, “movement of water molecules across a membrane from an area of high water concentration to an area of lower concentration until equilibrium” (McKinley). Diffusion is related to the movement of particles from an area of high concentration to an area of low concentration. Osmosis and diffusion are both passive transports that do not require energy although osmosis is the diffusion of water (Balmer). These transport processes occur......

Words: 2715 - Pages: 11

Biology Lab Report

...Introduction: The purpose of the experiment was to determine if a lighter concentration of salt would diffuse faster than a lower concentration in an equal amount of water. If the salt concentration is higher then it will diffuse faster because it should reach equilibrium faster. The salt bag dissolving into the waiter in an example of hypertonic osmosis. The water is moving into the membrane to dissolve the salt. Materials: • 2 beakers with 200ml of distilled water • 2 permeable membranes (bags) • 8 grams of salt • 1 graduated cylinder • 1funnel • 2 Total dissolved solids meter (TDS) • 1 pair of safety glasses • 1 digital scale • 1 timer • 4 strands of string Procedure: • Gather materials. • Place 200ml water in each beaker. • Prepair membrane. -soak in water. -blow in opening. -tie one end with string. • Add 20ml of water to each bag. • Weigh salt, add five grams to one bag and three to the other. • Tie the ends with string. • Record TDS of water in the beaker. • Start experiment: -Place salt bags into the beakers and start timer. • Record TDS every minute for five minutes Data/Observations: There were no visual observations of changes in the beakers. Discuss/Conclude: The hypothesis was correct. The beaker with I higher concentration of salt diffused faster as indicated by the higher TDS reading after five minutes, It was almost twice as much TDS than the other beaker. The TDS of the water before the salt was added should have......

Words: 322 - Pages: 2

Biology Lab Report 7

...Comparing The Resting Heart Rate and Recovery Time Of Males And Females After Physical Activity Devyn Jones 26 September 2014 Biology 140 Section 38 Dr. Maria Gainey Abstract In this study we tested to see whether or not males have a lower resting pulse rate and if males have a faster pulse recovery time after engaging in physical activity. The experiment groups are the males and females of the class. The experiment involves walking up and down a flight of stair s and recoding your pulse rate for a period of time. The average resting pulse for the males was 72 beats/min, and the average resting rate for females was 80. The average percent change was 35.7%, and the mean pulse recovery time is 4 minutes. The experiment only partially supported my hypothesis. Males have a lower resting heart rate than females, however females have a faster pulse recovery time than males. Introduction Cardiovascular fitness is frequently considered the most important aspect of physical fitness. In lieu of this statement, we tested which group, males or females, have a better cardiovascular fitness. I believe that males have a lower resting heart rate than females, and a faster recovery time after a period of exercise. In the experiment two groups will be tested, males, and females, they will undergo the step test, take a series of pulses, and record their results. If my hypothesis is valid then the results will show that males have a lower resting heart rate, and display a faster......

Words: 741 - Pages: 3

Diffusion Lab

...Fatmata Diffusion Abstract dialysis tubing is, made of cellulose because it’s a selectively permeable membrane. In this experiment, we are testing to see if the solution in the beaker moves into the dialysis bag. Which because of that, Introduction Diffusion and osmosis are two types of transport mechanisms. Diffusion is the movement of molecules from areas of higher concentrations to areas of lower concentration until the molecules are evenly distributed through the area. Osmosis is the dispersion of water. Our cells are capable of absorbing nutrients because, the cell membrane is selectively permeable (some molecules can diffuse freely through the membrane while others cannot). In this experiment we used dialysis bag as a model of the cell membrane. Our hypothesis was that the glucose will diffuse out of the membrane into the beaker filled with iodine solution. To demonstrate dialysis tubing we used water, starch and iodine. When starch and iodine react together they form a dark brown color. Materials Rubber band | Dialysis bag | Beaker | Glucose solution | Iodine solution | Water, thread | Methods * Cut a piece of dialysis tubing that has been soaking in water approximately 40 cm (approx. 16 in) long, Tie the end of the dialysis tubing with two or more knots. * Fill the bag halfway with glucose solution. And add 4 full droppers of starch solution to the bag. * Hold the open end close while you mix the content o the bag. Rinse of outside the bag...

Words: 535 - Pages: 3

Osmosis Lab Report

...Osmosis of Water Biology 105 Lab 3/22/11 Introduction Cells have kinetic energy, a source of energy stored in cells. This energy causes molecules to bump into each other and move in new directions. Diffusion is one result of this molecular movement. Diffusion is the random movement of molecules from an area of higher concentration to areas of lower concentration. Osmosis is a special kind of diffusion where water moves through a selectively permeable membrane that only allows certain molecules to diffuse though (Lab Manual 7e, 2010). Diffusion or osmosis occurs until dynamic equilibrium has been reached. This is the point where the concentrations in both areas are equal and no net movement will occur from one area to another. If two solutions have the same solute concentration, the solutions are said to be isotonic. If the solutions differ in concentration, the area with the higher solute concentration is hypertonic and the area with the lower solute concentration is hypotonic. Besides osmosis and diffusion, molecules and ions can be moved by active transport. This process includes the use of ATP (adenosine tri-phosphate) to drive molecules in or out of a cell. Active transport is generally used to move molecules against a concentration gradient, from an area of low concentration to an area of higher concentration of molecules. The purpose of this experiment was to show that osmosis of water thru plant stomata does not require energy......

Words: 756 - Pages: 4

Osmosis Lab Report

...473g -0.047g 20 2 0.42g 0.411g -0.009g 40 1 0.50g 0.323g -0.177g 40 2 0.51g 0.313g -0.197g Conclusion To conclude, I am able to see the effect of different concentration on the rate of osmosis through this experiment. The experiment was done by measuring the mass of potato before and after osmosis. And the result was that as the concentration increase, the rate of osmosis also increases, this tells that there is a decrease in mass. And it shows that my hypothesis was correct, “the concentration of sugar where the water potential is higher than the water potential of the potato, the mass of the potato will increase. On the other hand, if they have similar water potential, the mass will not change.” According to the osmosis theory, if the concentration of the sucrose solution increase, the particles’ water potential will also increase, and will become higher than the particles that are in the potato. Evaluation During the experiment, there are some errors that cannot be able to control, such as the temperature of the room. This might slightly change the result yet make the experiment not a fair test. Another thing that would affect the experiment is that the sugar might not dissolve properly to the solution, and this might affect the rate of osmosis. If I have to do this investigation again, I would mix the solution better and to do the experiment in a controlled room temperature to maintain a better result....

Words: 732 - Pages: 3

Osmosis and Diffusion

...processes use energy to move substances across the membrane. Osmosis Lab 2. Explain your observations in detail in terms of concentration gradient, diffusion, osmosis, osmotic pressure, passive transport, and active transport. A. The osmosis lab was a really awesome lab. It gave you the excitement for three days to see how much the egg has changed. Concentration gradient is a ongoing change in the concentration of solutes in a solution as a function of distance through a solution. The concentration gradient of the egg was almost seeing through. You could see the eggs membrane and the yellow oak that was in the center of the egg. Diffusion is the tendency of atoms, molecules, and ions in a liquid or air solution to move from areas of higher concentration to areas of low concentration to become more diffuse. For the diffusion of the egg, the egg expanded and got higher concentration of the water outside of the membrane and a lower concentration inside the osmosis. Osmosis is the movement of water across a selectively permeable membrane into a compartment containing solute that cannot cross the same membrane. The osmosis is what causes the bubbles. Osmotic pressure is the ability of osmosis to generate enough pressure to lift a volume of water. The water equilibrates in the jar. The passive transport exchanges the oxygen 02and C02 in the jar. Active transport of the osmosis lab was against the gradient. Ph.I.L.S Lab 3. Explain what happened to the blood cells at the......

Words: 579 - Pages: 3

Biology Lab Manual

...BIOLOGY 10 Introduction to Biology Laboratory Manual Prepared by: KLLabrador Table of Contents |Exercise |Title |Page No. | |1 |Observation and Description |2 | |2 |Formulation, Testing of Hypothesis, |6 | | |and Experimental Design | | |3 |The Use of Models and Controls |9 | |4 |Plant and Animal Tissues |14 | |5 |Cellular Respiration |22 | |6 |Photosynthesis |27 | |7 |Phylogeny and Systematics: Survey of Plant and Animal Families |30 | | ...

Words: 6127 - Pages: 25