IntroductionThe cell has many different structures that carry out different instructions necessary for the body to function. One of the many structures is the plasma membrane. The plasma membrane acts as a gate allowing molecules to enter the cell. However, this membrane is selectively permeable, meaning that it gives and prevents access to certain molecules. Molecules travel regularly through the cell and some of these molecules are actively transported across the membrane. This is called active transportation. Active transport is the transport of particles against their concentration gradient with cellular energy. Unlike active transport, diffusion and osmosis occur. These are passive transports. Passive transport is movement down the concentration gradient from high to low concentration and does not require cellular energy. A gradient is anything that is unevenly distributed. Diffusion is the movement of dissolved particles from a high concentration to a lower concentration (Bres and Weishar 61). Osmosis is a type of diffusion. Osmosis is the movement of water from an area of ​​high concentration to an area of ​​lower concentration (Campbell, Dickey, Reece, and Simon 84). Osmosis and diffusion remove waste and provide cells with necessary nutrients. In this laboratory, to detect the process of diffusion and osmosis, the stock solution was in the dialysis bag. Then it was placed in distilled water for twenty minutes. The mass of the dialysis bag was recorded before and after its placement in the distilled water. Initial and final weight were recorded. Through observations from these experiments, I should be able to see the operation of a selectively permeable membrane across the dialysis bag. The dial...... middle of paper...... huge and they would damage the cell if they went through it. This process is similar to breathing in the human body. Oxygen enters the body and carbon dioxide is expelled. Oxygen leaves the air and enters the blood because it is richer in the air, while carbon dioxide diffuses on its own gradient from the blood to the air in the lungs. Oxygen is carried by hemoglobin molecules found in red blood cells (Campbell, Dickey, Reece, and Simon 512). If carbon dioxide were to accumulate in the cell or enter the cell, it would poison the cell. Conclusion There was water movement by osmosis in the dialysis bag. There was movement of particles by diffusion in the distilled water. They both moved from a more concentrated area to a less concentrated area. The hypothesis was supported by the experiments carried out in this laboratory.