...different mechanisms used by the body to transport substances across the cell membrane. One of these methods is called Simple diffusion. Simple diffusion involves molecules diffusing from an area of higher concentration to an area of lower concentration. Simple diffusion happens through random movement of particles through the cell membrane. Carbon dioxide and other gases such as oxygen and ethanol uses simple diffusion as a method of cell transportation. Several factors affect the rate of diffusion including high temperatures and the size of the molecule. A smaller molecule will diffuse much quicker than a larger one as it is able to move about without difficulty. Concentration gradient and the distance of diffusion also makes a...
Words: 501 - Pages: 3
...First I will describe the parts of the cell. The cell wall is a rigid box like structure found in plant cells. The cell wall protects the cell from unwanted particles , and stops the cell from bursting when too much water is present inside the cell. The cell membrane is responsible for five types of diffusion. The first diffusion is simple passive. Simple transport allows small particles to pass through the phospholipid bilateral from a high to low concentration. Examples of particles that can pass through the phospholipid bilayer are lipids, water, and other small particles. The second type of diffusion is active transport. Active transport goes from low to high concentration, therefore it uses ATP to allow particles through the cell membrane....
Words: 893 - Pages: 4
...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
...Computer Networks 53 (2009) 2753–2766 Contents lists available at ScienceDirect Computer Networks journal homepage: www.elsevier.com/locate/comnet Molecular communication options for long range nanonetworks Lluís Parcerisa Giné *, Ian F. Akyildiz The Broadband Wireless Networking (BWN) Laboratory, School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA a r t i c l e i n f o a b s t r a c t Nanotechnology is an emerging field of science devoted to provide new opportunities in a vast range of areas. In this paper, different techniques are proposed to enable the long range interconnection of nano-machines, deployed over distances from a few centimeters up to several meters. Long range nano-communications will enable the development of applications that could not be implemented using other techniques. The usage of both short-range nano techniques and long range micro techniques are not practical or are unfeasible for a huge application scope. Biologically inspired research provides promising features to long range communication, such as very low power consumption and biocompatibility. In this paper, several bio-inspired techniques are discussed following a twofold taxonomy divided according to whether a fixed physical link is required for signal propagation or not, i.e., either wired or wireless communication. In the first group, pheromones, spores, pollen and light transduction are discussed. In the second group, neuron-based...
Words: 11420 - Pages: 46
...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 these glucose molecules are able to pass through the cells membrane...
Words: 1656 - Pages: 7
...Penetrating molecules, which are molecules with the ability to pass through the lipophillic barrier of the cell membrane, brings about the influx of small water molecules via osmotic diffusion. The rate for erythrocyte to hemolyze is directly related to the rate of osmotic. If the solute cannot penetrate through the cell membrane and pull water with it, no hemolysis will occur. Therefore, the rate of hemolysis can also be used as an indicator of the diffusion rate for particular penetrating solutes (Bakko, 1985; Giese, 1963). There are aqueous channels (water filled pores) present in the surface of the cell membrane which is involved in the maintenance of the molecules diffusing through the channels.With diameters that are less than 1.0 nm...
Words: 692 - Pages: 3
...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
...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
...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
...Barriers to Movement Part A: demonstrating differential permeability Part B: A model for osmosis Aim: To observe and record the effects a differentially permeable membrane has on the process of diffusion. To observe and examine the process of osmosis. Partner: Phil Reichelt Results: Part A demonstrating differential permeability Table 1 results of test: | Water in tube at start of experiment (distilled water) | Water in tube at start of experiment (distilled water) | Water in tube at end of experiment | Water in tube at end of experiment | | clinistix | Iodine test | clinistix | Iodine test | Results | Glucose not present in deionised water | Starch not present deionised water | Glucose present in external deionised water | No evidence of starch being present | interpretation | The water is not contaminated | The water is not contaminated | Glucose has diffused through the membrane | No change | Part B results shown on the following page Discussion: PART A – 3) a. The two substances present in the dialysis bag at the start of the experiment were glucose and starch. In the solution outside the dialysis bag, we later found the presence of glucose, indicating it had moved from the inside of the dialysis bag into the external deionised water. The reasons for glucose being able to penetrate the membrane is because glucose is a monosaccharide molecule (simple sugars) and a small enough to pass through the pores of the membrane ( dialysis bag). b. The...
Words: 895 - Pages: 4
...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
...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
...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
...ABSTRACT: This experiment was to observe diffusion happening within the cells, and to help understand the sizes of molecules and how the chemical reactions take place. Therefore, the experiment was conducted using glucose and starch solution inside the dialysis tube. The starch and glucose that was put inside the dialysis tube help identify which of the two will reacted with potassium iodide inside the breaker, as the latter passed from the beaker into the tube, the glucose/starch solution's change of color showed that the potassium iodide was small enough that it able to pass through from the solution and into the bag. After the Benedict test, glucose from the bag was also founded small enough that it can exit from the bag and into and solution. In the end, glucose and potassium iodide was the only two that is capable to move freely in and out within the bag, while starch molecules was too big so it got contain inside. Introduction:...
Words: 930 - Pages: 4
