...which are the solutes, or dissolved substances. Organelle membranes and the plasma membrane are selectively permeable, allowing water to freely pass through but regulating the movement of solutes. The cell actively moves some dissolved substances across membranes, expending adenosine triphosphate (ATP) (biological energy) to accomplish the movement. Other substances move passively, without expenditure of ATP from the cell, but only if the cell membrane is permeable to those substances. Water and selected solutes move passively through the cell and cell membranes by diffusion, a physical process in which molecules move from an area where they are in high concentration to one where their concentration is lower. The energy driving diffusion comes only from the intrinsic kinetic energy in all atoms and molecules. If nothing hinders the movement, a solute will diffuse until it reaches equilibrium. EXERCISE 1. Diffusion of Molecules Through a Selectively Permeable Membrane Materials string or rubber band 500 – mL beaker one-third filled water sharpie handheld test tube holder 30 % glucose solution 3 standard test tubes starch solution disposable transfer pipettes I2KI solution 2 400 – mL beakers to hold dialysis bag Benedict’s reagent 30 – cm strip of moist dialysis tubing hot plate 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...
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...atoms that are independent, rapid, and random in motion. These molecules frequently collide with each other and with the sides of the container. In a period of time, this movement results in a uniform distribution of the molecules throughout the system. This process is called diffusion (Everett and Everett, n.d.). Diffusion is defined as the movement of molecules away from the area of their highest concentration to an area of low concentration. Net diffusion can be restated as the movement of particles along the concentration gradient. According to Meyertholen (n.d.), there are several factors which may affect the rate of diffusion of a substance. These factors include the following: (1) Temperature: higher the temp-higher the rate of diffusion, (2) Size of particle: bigger the particle-higher the energy to diffuse , (3) State of matter: solid takes more time to diffuse compared to liquids, liquids take more time to diffuse compared to gases and gases take less time to diffuse compared to liquids and solids, (4) Nature of matter: denser the matter-slower the rate of diffusion. My objective was to determine the properties of ammonia (NH3) and of hydrochloric acid (HCl) that are related to diffusion. I hypothesized that ammonia diffuse faster than hydrochloric acid. For more support we conduct also an experiment that would detect the diffusing substances in an agar plate using colored compounds; potassium permanganate, methylene blue and potassium dichromate MATERIALS...
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...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...
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...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...
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...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...
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...NEWS-ON-MOBILE NEWSLAND DIFFUSION OF INNOVATION THEORY One of the greatest pains to human nature is the pain of a new idea. It...makes you think that after all, your favourite notions may be wrong, your firmest beliefs illfounded... Naturally, therefore, common men hate a new idea, and are disposed more or less to ill-treat the original man who brings it.-Walter Bagehot Physics and Politics Definition of Diffusion of Innovation In his comprehensive book Diffusion of Innovation, Everett Rogers defines diffusion as the process by which an innovation is communicated through certain channels over time among the members of a social system. Rogers' definition contains four elements that are present in the diffusion of innovation process. The four main elements are: 1. Innovation - an idea, practices, or objects that is perceived as knew by an individual or other unit of adoption. 2. Communication channels - the means by which messages get from one individual to another. 3. time - the three time factors are: • • innovation-decision process Relative time with which an innovation is adopted by an individual or group. • Innovation’s rate of adoption. 4. Social system - a set of interrelated units that are engaged in joint problem solving to accomplish a common goal. Make a better mousetrap, and the world will beat a path to our door. -Ralph Waldo Emerson Background on Diffusion of Innovation The original diffusion research was done as early as 1903 by the French sociologist...
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...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...
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...Diffusion of Innovation Theory: In communications and Media By: Dezro’ Hill Agnes Scott College Public Health 202 Spring 2013 Environmental and Health Communications Diffusion of Innovation Theory: In communications and Media In Communications there are various ways that professional’s communication with society to make the world a better place. Media is a helpful form of communication when trying to inform society of important information. However sending these messages can sometimes be difficult when creating. Therefore, professionals have found ways in which they are able to communicate these messages depending on the subject. Theories are the skills which professionals use to communicate these messages depending on the subject. One important theory that is use is the Diffusion of Innovation Theory which is used to communicate with society. The Diffusion of Innovation Theory is a theory that addresses how new ideas and concepts, and/or practices are diffused throughout a community or society. The theory was developed by Everett Rogers in 1962. The theory has five subgroups in which audiences fall under when adapting the new idea, innovators, early adopters, early majority, late majority, and laggards. The innovators are the people in the community to create the idea and inform the people in the community about it. These are the people in the community who uses different communication outreaches to inform the community about what’s going on and how they can...
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...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...
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...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...
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...**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...
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...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...
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...Observations on the Characteristics of Diffusion A Scientific Paper Submitted to Professor Christina Barazona College of Science and Mathematics - Department of Biological Sciences Mindanao State University – Iligan Institute of Technology Andres Bonifacio Avenue, Tibanga, 9200 Iligan City, Philippines By Janna R. Andalan August 2013 ABSTRACT The Experiment conducted involves diffusion. The point of this experiment was to know the characteristics of diffusion and to formulate hypothesis based on diffusion. It has also a purpose to see whether the diffusion is dependent on distance, rate and molecular weight of the substance. The estimation of distance is predicted by getting the average of the substance. Rate is predicted by subtracting the final diameter to initial diameter and dividing it by time. It is determined that there are three things which influence the movement of molecules such as kinetic energy, nature of the environment and size of the molecules. By this, we know which dye diffused at the fastest rate by measuring the diameter of the colored area immediately after adding the substance to the agar plate. After one hour of measuring the methylene blue by 15 minutes interval, the substance moved immediately in 0min until 45minutes, the remaining minutes remains the same. While on the potassium permanganate, the substance moved from 0minutes to 1hour. These happened because they had different molecular weight and also the size of the substance...
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...2 ABSTRACT The effect of molecular weight on the rate of diffusion was assessed using two tests: the glass tube test and the agar-water gel test. In the glass tube set-up, two cotton plugs soaked in two different substances (HCl and NH4OH) were inserted into the two ends of the glass tube. The substance with the lighter molecular weight value (NH4OH, M = 35.0459 g/mole) diffused at a faster rate (dAve = 25.8cm), resulting in the formation of a white ring around the glass closer to the side of the heavier substance (HCl, M = 36.4611 g/mole; dAve = 10.8 cm). The agar-water gel set up was composed of a petri dish of agar-water gel containing three wells. Drops of potassium permanganate (KMnO4), potassium dichromate (K2Cr2O7) and methylene blue were simultaneously introduced to each well. Methylene blue, having the largest molecular weight, displayed the smallest diameter (18 mm) and diffused at the slowest rate (0.3668 mm/min.). Thus, the higher the molecular weight, the slower the rate of diffusion. INTRODUCTION A substance in the gaseous or liquid state consists of molecules or atoms that are independent, rapid, and random in motion. These molecules frequently collide with each other and with the sides of the container. In a period of time, this movement results in a uniform distribution of the molecules throughout the system. This process is called diffusion (Everett and Everett, n.d.). Diffusion occurs naturally, with the net movement of particles flowing from...
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...ABSTRACT The effect of molecular weight on the rate of diffusion was assessed using two tests: the glass tube test and the agar-water gel test. In the glass tube set-up, two cotton plugs soaked in two different substances (HCl and NH4OH) were inserted into the two ends of the glass tube. The substance with the lighter molecular weight value (NH4OH, M = 35.0459 g/mole) diffused at a faster rate (dAve = 25.8cm), resulting in the formation of a white ring around the glass closer to the side of the heavier substance (HCl, M = 36.4611 g/mole; dAve = 10.8 cm). The agar-water gel set up was composed of a petri dish of agar-water gel containing three wells. Drops of potassium permanganate (KMnO4), potassium dichromate (K2Cr2O7) and methylene blue were simultaneously introduced to each well. Methylene blue, having the largest molecular weight, displayed the smallest diameter (18 mm) and diffused at the slowest rate (0.3668 mm/min.). Thus, the higher the molecular weight, the slower the rate of diffusion. INTRODUCTION A substance in the gaseous or liquid state consists of molecules or atoms that are independent, rapid, and random in motion. These molecules frequently collide with each other and with the sides of the container. In a period of time, this movement results in a uniform distribution of the molecules throughout the system. This process is called diffusion (Everett and Everett, n.d.). Diffusion occurs naturally, with the net movement of particles flowing from an area...
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