Cell Transport Essay

Cellular transport refers to the movement of compounds across a cell’s plasma membrane. The cell must be able to transport these compounds across the membrane in order to regulate the characteristics of this transport (Reece, 124). The plasma membrane is selectively permeable because of the molecular composition of the plasma membrane, the cell is selective about what comes in and out. (Physio ex 9.1). Cell transport is separated into two distinct aspects: passive transport and active transport. Passive transport refers to the movement of molecules between the interior and exterior of the cell through differences in concentration or pressure gradients. Active transport requires energy known as ATP (Adenosine Tri-phosphate) for the transport to occur.

The purpose of this experiment is to explore different cell transport mechanisms and cell permeability, including concentration gradient, molecular weight and size, rate of diffusion, and the effects. In this experiment we will focus mainly on passive transport. There are two distinct categories of passive transport: diffusion and filtration.

Osmosis is a special type of diffusion where water is diffused across the membrane relatively freely in order to maintain a balance in water concentration on each side of the membrane. When referring to osmosis, it is important to understand tonicity. This is the way the solution affects the volume of the cell. An isotonic solution is a solution in which the concentration of solutes inside the cell is the same as the concentration outside of the cell. A hypertonic solution is a solution in which the concentration of solutes inside the cell is lower than the concentration of solutes outside of the cell. This would cause the cell to shrink. A hypotonic solution is a solution in which the concentration of solutes inside the cell is higher than the concentration of solutes outside of the cell. This would cause the cell to burst (Wood,