Water - The Elixir of Life

Remember your first Biology lab? The professor had you get a few drops of water from the fish tank and put it under the microscope. What did you see? I remember seeing a lot more than I bargained for! Thinking the water was just that, water, I was surprised to see so much life. There were many small, single celled animals swimming in that brew. It was amazing. The one I remember studying the most was the Protozoa, in particular the Paramecium. It looked like a small oval filled with specks of dust and dirt and surrounded by tiny hairs that helped it move through the water like so many oars on a Viking Ship. Could these tiny drops of life live without water? We know they cannot. Water is the medium of life, the substance in which an organism naturally lives and grows. It constitutes over 70% of our body mass.

Water has many distinct properties that set it apart from other substances and make it critical for life. The chemical reactions in our bodies need a fluid to allow for the movement of large protein molecules into position to react, to fold and unfold, to bring in substrates and take away waste. These reactions use the hydrogen bonds of water to dock the substrates into position for these enzymes to do their thing. All known forms of life depend on water. It is vital both as a solvent in which the body's chemicals dissolve and as an essential part of metabolism within the body. Water allows organic compounds to react in ways that result in the replication of these molecules and the formation of new ones. Water is both removed from molecules in order to grow larger molecules and used to break bonds to generate smaller molecules. The hydration of all sorts of molecules, large and small, is required to make life happen. Without water, these metabolic processes could not exist, with no known processes available to take their place.

To function properly, the human body requires water daily to avoid dehydration; the precise amount depends on the temperature, humidity, and your personal level of activity. Most of this needed water is ingested through foods or beverages other than drinking pure water. About 20 percent of our water intake comes from food, while the rest comes from drinking water and other beverages, including caffeinated ones. Water is excreted from the body through urine and feces, through sweating, and by exhalation of water vapor from the lungs. With physical exertion and heat exposure, water loss will increase and daily fluid needs can increase.

Medical science favors an average daily consumption of approximately one liter of water, excluding extra water needed to replace fluids lost from exercise or warm weather. If your kidneys are healthy, it is difficult to drink too much water, but it is possible and dangerous to drink too little. You can drink far more water than necessary while exercising, however, risking water intoxication which is potentially fatal. The "fact" that a person should consume eight glasses of water per day has no scientific basis. Other myths, such as the effect of water on weight loss and constipation, have also been debunked.

In plants, the capillary action of water draws it to the top of the tallest trees. In most forms of plant life, photosynthetic cells use the sun's energy to split off a hydrogen from water. This hydrogen is then combined with carbon dioxide (CO₂) to form glucose and the reaction releases oxygen back into the air. All living cells then use this glucose, oxidizing the hydrogen and carbon, releasing energy and reforming water and CO₂ in the process. In this way water is integral to the balancing of oxygen and carbon dioxide in the atmosphere.

In the ocean, water supports all forms of life, from the smallest plankton to the massive blue whale. The transmission of light through the water allows photosynthesis in shallow reefs, while the air dissolved in the water provides oxygen for the fish. Water's high heat capacity also helps to maintain a consistent temperature, both in the water and in the atmosphere above it, making it possible for marine life to flourish.

Copyright (c) 2004
Richard Ling


Water is essential to all living things. Without it, life as we know it could not exist on earth. It is truly one of the most amazing molecules in God's Chemistry Set.

"The Spirit and the bride say, 'Come!' And let him who hears say, 'Come!' Whoever is thirsty, let him come; and whoever wishes, let him take the free gift of the water of life. Revelation 22:17 (NIV)"