Experiment on the Functions of Passive Transport in Red Blood Cells

Introduction

Because of cell's composition, the plasma membrane has to be selective to its materials that passes through it. In other words, the plasma membrane is semi-permeable that it allows nutrients to enter the cell but keeps out undesirable substances. This property allows the cell to segregate its inner cytoplasm from the external environment. There are two different ways to pass though this membrane: active and passive transport. Active and passive transport are both biological process that move oxygen, water and nutrients into cells and remove waste products; however, these two processes happen in a different mechanism.

First, active transport requires chemical energy because it is the movement of biochemical from areas of lower concentration to areas of higher concentration. Therefore this process uses ATP to pump molecules against the concentration gradient. Active transport is one of important biochemical process because amino acids, complex sugars and macromolecules need to enter the eukaryotic cells for their survival. These molecules are very essential for living, but these items either cannot diffuse or diffuse too slowly without active transport process. Sodium and potassium across though cell membrane by protein pump, and it is one of great example of active transport.

On the other hand, passive transport moves in the natural way. Biochemical moves from areas of high concentration to areas of low concentration, therefore, it does not require energy. Diffusion, facilitated diffusion and osmosis are passive transport. Because the cell membrane is compose of phospholipids, anything soluble in lipids, small monosaccharide, water, oxygen, carbon dioxide, and hormones can across this membrane without ATP. These mol...

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...d, 2001) From this process, it shows that when osmosis function does not work properly in human body, the person cannot sustain his or hers life normally.

Moreover, the critical situation could happen without any failure of biological function when a person drinks salt water. The human body can handle a little bit, but if somebody consumes nothing but salt water for few days, as in the case of being stranded on the proverbial desert island, the osmotic pressure would begin drawing water from other parts of the body. Since a human body ranges from 60% water in an adult male, and to 85% in a baby, water is the essential ingredient in the human body. If a person continued to ingest salt water, he or she would eventually experience dehydration and die. Therefore, osmosis is very important and basic function for body even though this process seems very simple and easy.