Diffusion Lab Report

Diffusion Lab Report

Bio 100 Lab May 10, 2014

Introduction: All molecules have kinetic energy, “the energy a system possesses as a consequence of its state of motion” and are constantly in motion. This motion causes the molecules to move constantly, bump into one another each other and move in different directions. The result is diffusion. ( Cundy, 2012) Diffusion is the random movement of molecules from an area of higher concentration of molecules to an area of lower concentration. Cells have selectively permeable membranes that only allow the movement of certain solutes. ( Cundy, 2012) Diffusion plays a critical role in function of a cell. Scientists use specific terms to identify compounds in and around living cells. A solution is any combination of a solute (a dissolved substance) and a solvent (the fluid into which the solute has dissolved. For example, a glass of water is a solvent. If you add salt to the water, the salt is the a solute. A solution is formed when the water and salt are combined. “Diffusion is the passive transport of a substance in response to a concentration gradient.” ( Cundy, 2012) Molecules can move either in or out of the cell as long as the membrane is permeable to the molecule. (eScience) A selectively permeable membrane means that the membrane will only allow certain molecules through such as water, small solutes, oxygen, carbon dioxide, and glucose. Generally, molecules move towards the area of lower concentration.

Background Information: Diffusion is the process when a solution goes from a higher concentration to a lower concentration Solutions can have three relationships with each other; isotonic, hypertonic, or hypotonic. When the solutions have the same concentration of solutes, they are isotonic. Water is isotonic and moves freely across the cell membrane and helps maintain its fluid mosaic model characteristic. Hypertonic solutions are solutions with higher amounts of solutes and hypotonic solutions are solutions...