Biological Importance of Water

Semipermeable membrane, Xylem, Root pressure

Water (H₂O) is a liquid at room temperature, and its unusual properties provide the basis of many biological processes and organisms. In humans water is the vital product of respiration (C₆H₁₂O₆ + 6O₂ = 6CO₂ + 6H₂O.) The importance of water being produced as a product of respiration is that water is a main component of the human body (a human body consists of 65% water), and plays a key role in many biological processes that occur.

Water in the body had a large effect on the movement of substances in and out of cells. The phospholipids bilayer of a cell surface membrane provides the structure of the cell due to the hydrophobic (orientates away from water) tail and the hydrophilic (orientates towards water) head. The properties of these phospholipids in conjunction with water maintain the shape of the cell and movement through it via protein channels which are imbedded inside. The movement of water in the body is dependent on many organic substances e.g. glucose. These substances vary the water potential of the area. Osmosis is the movement of water from high water potential to lower water potential through a partially permeable membrane. If there is an area of high glucose concentration it will have a low water potential, thus causing water to diffuse into the area via osmosis. This concept is how water moves in and out of cells. It is important that the water potential of cells is maintained at a suitable level, or the cells will become either swollen, (which may result in the cell bursting) or shrinks. Because cells are important for normal bodily function it is important that the water content of the body is maintained in order for humans to survive. In digestion, all substances are broken down into smaller more soluble substance which can be carried by water in the blood and delivered to the parts of the body which require it; it acts as a transport medium. If blood was not made up largely of water then the required substances would not be transported to...
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