Diffusion And Diffusion Essay

Introduction

The cell has many different structures that carry out different instructions that are needed for the body to function. One of the many structures is the plasma membrane. The plasma membrane acts as a door that allows molecules to enter the cell. However, this membrane is selectively permeable, which means that it gives and prevents access certain molecules. Molecules travel regularly across the cell and some of these molecules are actively transported through the membrane. This is called active transport. Active transport is the transportation of particles against their concentration gradient with cellular energy. On contrary to active transport, diffusion and osmosis occur. These are passive transport. Passive transport is movement down the concentration gradient, moves from a high concentration to a low concentration, and does not require cellular energy. A gradient is anything that is distributed unevenly. 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 a high concentration to a lower concentration (Campbell, Dickey, Reece and Simon 84). Osmosis and diffusion get rid of wastes and supply the cells with needed nutrients.

In this lab, to detect the process of diffusion and osmosis, stock solution was into the dialysis bag. Then, it was placed in distilled water for twenty minutes. The mass of the dialysis bag was recorded before and after it was placed in distilled water. The initial and final weight was recorded. With observations of these experiments, I should be able to see the function of a selectively permeable membrane through the dialysis bag. The dial...

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...arge and they would damage the cell if they had moved through. This process is similar to respiration in the human body. Oxygen enters the body and carbon dioxide expels. Oxygen moves out of the air and into the blood because it is richer in the air while carbon dioxide diffuses along its own gradient, from the blood out into the air in the lungs. Oxygen is carried by hemoglobin molecules in the red blood cells (Campbell, Dickey, Reece and Simon 512). If carbon dioxide was supposed to build up in the cell or renter the cell, it would poison the cell.

Conclusion

There was a movement of water though osmosis into the dialysis bag. There was a movement of particles through diffusion into the distilled water. Thy both moved from a higher concentrated area to a lower concentrated area. The hypothesis was supported by the experiments that were carried out in this lab.