The movement of molecules has two forms of transport across the plasma membrane: active transport and passive transport. Active processes require energy, such as ATP, for molecules to be transported. In active transport, the cell administers ATP. In passive processes, no energy is required and changes in pressure and concentration are the driving forces. Processes such as simple diffusion, facilitated diffusion, osmosis, and filtration are characterized as passive transport, while solute pumps are a form of active transport. Each of these forms of transport occurs in the cells of all living organisms and is essential for life. The process of diffusion occurs in and out of a cell as molecules move from areas of higher concentration to a region of lower concentration, and this variation in concentration is described as a concentration gradient. i For locomotion to occur, molecules use its kinetic energy and constant motion. The cell's barrier is its plasma membrane, which allows molecules to pass through pores if they are small enough. i The plasma membrane has a phospholipid bilayer that separates the interior (the cytoplasm) and the exterior (the extracellular fluid and lipid-soluble solutes) of the cell. The fact that the plasma membrane monitors the passage of molecules according to their size and solubility makes it semi-permeable. Diffusion can be classified as simple diffusion or facilitated diffusion. A similarity between simple diffusion and facilitated diffusion is that they are both passive processes and movements from areas of higher concentration to regions of lower concentration. Simple diffusion only takes place across a phospholipid bilayer and only occurs for small non-polar areas of the paper in the human body to combat cancer cells and microorganisms that could potentially be harmful. to the body. Knowing that simple diffusion is a passive process, I hypothesized that the greater the MWCO (Molecular Weight Cut Off), the more solutes will pass through the semi-permeable membrane. For activity 2, I hypothesized that by accumulating more transport proteins, the rate of solute transport increases. I hypothesized in Activity 3 that the concentration gradient and osmotic pressure were related; as the concentration gradient increased, the osmotic pressure also increased. As for activity 4 relating to filtration, I hypothesized that as the pore size or pressure increases, the filtration rate accelerates. Since active transport requires ATP, for activity 5 I assumed that as the concentration of ATP increases it will allow active transport to occur more often..