Osmosis And Diffusion Essay

Osmosis is the diffusion of a solvent across a selectively permeable membrane that occurs in response to differences in solute concentrations (Allen and Harper 2014). Osmosis can fall under the category of passive transport which does not require energy. With osmosis being a type of diffusion it is viewed as molecules moving from a high concentration to a low concentration. To further explain if there is a low water concentration, high amounts of solutes will be present. Water will most likely move to areas where the solute concentration is high, which demonstrates why there would be less water concentration.

When conducting the osmosis lab, the initial tonicity of the cell was 0 grams. The beginning weight of the cell was 18. 75 grams and the ending weight was 17. 35 grams. Tonicity will allow you to determine the direction in which osmosis occurs. In the osmosis experiment the environment was the deionized water. The cell was the cytoplasm which was placed in a dialysis membrane that represented a selective permeable cell plasma membrane and was placed in the deionized water. After one hour, the weight of the cell decreased which demonstrates that the cell was placed in a hypotonic solution.

The cell swelled until it busted this explains why some of the cell leaked out. When conducting the biochemical tests for osmosis the cytoplasm represented the cell and the environment was the beaker of water. There were four substances tested such as glucose, albumin, NaCl and starch. Test tubes were used to distinguish the cell from the environment. Three milliliters of Benedict’s solution was added to the cell and the environment for glucose and placed in boiling water. The cell color was orange and the environment color was reen, this indicated that reducing sugars were present.

When conducting the albumin biuret test, two test tubes were used to indicate the cell and the environment. Two milliliters of environment was added to the environment test tube and one milliliter of cytoplasm was added to the cell test tube. Five to ten drops ten drops each of NaOh and CuSO4 was added to each test tube. A light purple substance appeared in the cell which indicated the presence or protein the environment presented a light blue substance which indicated no protein was present.

When conducting the AgCl test two to three drops of silver nitrates (AgNO3) was added to each test tube (the cell and environment). A white substance was present in each test tube which indicated Cl- ions were present. When conducting the Lugol’s Iodide test, three to five drops of Lugol’s Iodide was placed in the cell and the environment. The cell formed an indigo color which indicated that starch was present. The environment turned yellow which indicated no starch was present.

To sum this all up, if color was present in the environment this means that the contents of the cell has diffused through the cell membrane. Diffusion is when a substance moves from a high concentration to a low concentration until concentration is equal. Factors that affect diffusion are temperature, concentration, mass, solubility, density, surface area and thickness of the plasma membrane. The higher the temperature, the faster molecules will diffuse. A low concentration will also allow molecules to diffuse more rapidly.

When associating diffusion of molecules with solubility, lipid soluble material will pass more easily through the plasma membrane than polar material, which will allow the molecules to diffuse at a faster rate. Density and diffusion are inversely related. When the plasma membranes surface area is increased it slows the rate of diffusion and vice versa. Diffusion can take place in a liquid and gas. To test diffusion in a liquid, take two flasks and set them at different temperatures. To accomplish the temperature difference, one flask can be placed on ice and one should be left at room temperature.

The flask should be placed on ice for about fifteen minutes until the water temperature is equal to the ice bath temperature. To indicate the rate of diffusion one milliliter of dye solution can be placed in each flask. Over period of one hour the colder flask will result in slower diffusion that the flask at room temperate. This experiment accurately supports that at higher temperatures molecules will diffuse faster. Diffusion in a gas can be tested by spraying a scent. However long it takes a person to smell the scent is the diffusion rate. Diffusion rate is measured in meters per second.

A factor that may affect diffusion in a gas is a vent causing turbulence which may affect the rate at which the molecules travel. Diffusion in the human body is very important. It allows the oxygen to move from air into blood and moves carbon dioxide out of the blood into the air in the lungs. Cells need energy to function and they get this energy in the form of glucose. Diffusion plays an important role in moving glucose from the blood to the cells. Osmosis occurs in the body when a hypotonic or hypertonic solution is inserted intravenously.

If a hypotonic solution is inserted through the veins the red blood cells will rupture and will not be able to function. A disease that affects osmosis as a delivery method is bronchitis. Bronchitis is when the bronchi is inflamed. It can be caused by teratogens such as air pollution or infections. The inflammation is caused by the mucus membrane swelling that lines the bronchi. A result of this, there is increased mucus production and decreased movement of the mucus by cilia. The size of the bronchi decreases and causes impaired breathing.