ABSTRACT
The diffusion rates of potassium permanganate, KMnO4 (MW: 158 g/mole), potassium dichromate, K2Cr2O7 (MW: 294 g/mole), and methylene blue (MW: 379 g/mole) were compared and observed on an agar-water gel. An amount of each of the three substances was dropped on the wells of the gel. The diffusion rates were recorded by measuring the diameters of the substances at a regular three-minute interval for thirty minutes. Potassium permanganate had the biggest diameter after 30 minutes. Methylene blue had the smallest diameter. Thus, the molar weight of a substance highly affects its diffusion rate.
INTRODUCTION
There are factors that greatly affect diffusion in simple animals. Diffusion is directly proportional to the temperature of its environment. At high temperatures, diffusion is rapid. On the other hand, diffusion is slow on low temperatures. The renewal of water inside and outside the surfaces of the organ, or whichever is involved in the organism, successfully helps diffusion. The increase of the surfaces which are in
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A line graph shows the relationship of the molecular weight (g/mole) of the substances to the average rates of diffusion (mm/min). Another line graph illustrates the relationship of the time elapsed (min) to the partial rate of diffusion (mm/min).
RESULTS AND DISCUSSION
Table 1 showed that all substances had a 5-mm diameter. Potassium permanganate (KMnO4) had the greatest diameter of diffused area after 30 minutes. It had 20 mm of diffused area. Potassium dichromate (KCr2O7) had an 18-mm diameter of diffused area. The substance that had the least diameter of diffused area was methylene blue. It had a 12-mm diameter of diffused area.
LITERATURE CITED
Potts, W.T.W. and Eddy, F.B. 1973. Gill potentials and sodium fluxes in the flounder Platichthys flesus. Journal of Comparative Physiology. Vol. 87, Issue 1: pp.
It started one day in a science classroom. That is where I learned about diffusion. Diffusion is the movement of a substance across a membrane, due to a difference in concentration, without any help from other molecules. (Unknown, 2) In the egg lab the egg experienced diffusion over the course of several days. During the lab I also learned about hypertonic solutions and hypotonic solutions. The hypertonic solutions concentration of the cell is less than the outside of the cell. (Trent, 1) Hypotonic solutions have a higher concentration in it than the area surrounding it. (Trent, 1) I learned about hypertonic solutions when we placed the egg in corn syrup which caused the egg to deform and become squished. I learned about hypotonic solutions when we placed the egg in water which caused the egg to swell. This process can also be defined as osmosis which is the diffusion of water molecules across a membrane. (Unknown, 2) When we first got the egg it would be an isotonic solution meaning that having equal tension (Unknown,1) which would mean that the same amount was inside the cell as outside of it. The purpose of the experiment was to learn about diffusion, concentration gradient, passive transport,
Investigating the Effect of Concentration on the Rate of Diffusion Aim: To find out if concentration affects the rate of diffusion. Prediction: I predict that the higher the concentration of acid the faster the reaction will be. Hypothesis: Diffusion is the spreading out of a gas or liquid from an area of low concentration to another area where it has a lower concentration until the overall concentrations are balanced. The Hydrochloric acid (HCl) diffuses into the gelatine cube of which contains Sodium Hydroxide (NaOH), which is an alkali. When the Hydrochloric acid combines with the Sodium Hydroxide they form salt and water, which is neutral therefore turning the pink cube to clear.
This cell membrane plays an important part in Diffusion. Cell membrane and Diffusion Diffusion is the movement of the molecules of gas or liquids from a higher concentrated region to a lower concentration through the partially permeable cell membrane along a concentraion gradient. This explanation is in the diagram shown below: [IMAGE] Turgor When a plant cell is placed in a dilute solution or a less concentrated solution then the water particles pass through the partially permeable membrane and fill the cell up with water. The cell then becomes Turgor or hard. An example of this is a strong well-watered plant.
The side of the membrane that has the higher concentration is said to have the concentration gradient. It drives diffusion because substances always move down their concentration gradient. The pressure gradient also plays a role in diffusion. Where this is a pressure gradient there is motion of molecules. The pressure gradient is a difference in pressure between two different points.
Prediction: Draw a sketch to show the shape of the curve you expect for the solubility of a typical solid dissolving in water at different temperatures. Plot solubility on the y-axis and temperature on the x-axis.
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?
The experiment is aimed at giving a better understanding of the osmosis process and the different conditions in which osmosis occurs. INTRODUCTION When a cell membrane is said to be selectively permeable, it means that the cell membrane controls what substances pass in and out through the membrane. This characteristic of cell membranes plays a great role in passive transport. Passive transport is the movement of substances across the cell membrane without any input of energy by the cell.
On a cellular level, Mrs. Jones’ cells are dehydrated due to osmotic pressure changes related to her high blood glucose. Cells dehydrate when poor cellular diffusion of glucose causes increased concentrations of glucose outside of the cell and lesser concentrations inside of the cell. Diffusion refers to the movement of particles from one gradient to another. In simple diffusion there is a stabilization of unequal of particles on either side of a permeable membrane through which the particles move freely to equalize the particles on both sides. The more complex facilitated diffusion is a passive transport of large particles from a high concentration of particles to a lower concentration of particles with the aid of a transport protein (Porth, 2011). The cellular membranes in our bodies are semipermeable allowing for smaller molecules to flow freely from the intracellular to extracellular space. The glucose molecule, however; is too large to diffuse through the cellul...
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.
If a plant cell is places in a hypotonic solution the cell has a lower water concentration to that of the solution. Water will move into the cell by osmosis from a high water concentration outside the cell to a lower water concentration inside the cell through a selectively permeable membrane. The cell becomes turbid
Activity 3: Investigating Osmosis and Diffusion Through Nonliving Membranes. In this activity, through the use of dialysis sacs and varying concentrations of solutions, the movement of water and solutes will be observed through a semipermeable membrane. The gradients at which the solutes NaCl and glucose diffuse is unproportional to any other molecule, therefore they will proceed down their own gradients. However, the same is not true for water, whose concentration gradient is affected by solute ...
The gradient of the graph tells us whether the different rate curves have the same relation, meaning if they have a similar rate of reaction. Reactions can take place in a variety of customs; they can bee steep or steady. The steeper the slope, the faster the reaction takes place. The steadier the slope, the slower the reaction takes place. Aim:
...e the graph falls more steeply, flattening off at higher concentrations. I would also like to conduct an investigation, in conjunction with this experiment, to calculate the concentration of sap within the vacuole.
Osmoregulation is an example of an organism maintaining homeostasis. More specifically, osmoregulation involves an animal regulating osmotic pressure, or its fluid content. Brine shrimp, Artemia, use osmoregulation to regulate the saline levels of fluid within their body. Because brine shrimps live in seawater, an environment with a high saline concentration, they must actively excrete excess salt. Brine Shrimps use metepipodites as the location of the ion pump which secretes sodium. This is an active transport of ions because it is moving against the gradient, a higher salt content outside the body. The two following studies describe the environmental conditions ideal for brine shrimp and the possible genetic explanation for the osmoregulation of brine shrimp, respectively.
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.