Discuss the Biological Importance of Water

The hydrogen bonds in the water mean that it becomes less dense as it becomes a solid. This enables ponds and oceans to not freeze over. If ice is formed, it floats to the top and the water underneath will not solidify meaning that pond life and sea creatures can still live under ice. Water covers 71% of the earths surface mainly in oceans. Oxygen and carbon dioxide can dissolve in water, which provides sea creatures with oxygen to respire and live in deep oceans. The water is also transparent meaning that the suns rays can reach aquatic plants in the ocean enabling them to undergo photosynthesis.

Water is essential in the digestion process. Enzymes are dissolved in water and produced in the mouth and stomach which break down the food and enable the nutrients to be used. The nutrients are absorbed from the villi in the small intestine into the blood stream where they are transported and used by the body.

The blood the nutrients are transported is made up of 55% water. The blood plasma contains proteins, salts and other nutrients dissolved in the water. Many other substances also dissolve in the blood and are transported around the body to where they are needed, for example oxygen and carbon dioxide. Oxygen is dissolved into the blood from the alveoli in the lungs. The blood then transports the oxygen around the body and delivering it to cells, enabling them to respire and function properly. The blood also collects waste products such as carbon dioxide and urea. The carbon dioxide is transported back to the lungs where it is exhaled and the urea is transported to the kidneys where it is processed and travels to the bladder to be excreted as urine.

The cytoplasm of a cell is made up of 90% water. This is important as reaction such as respiration take place in solution in the cytoplasm, so they can be carried out more easily and more efficiently. In condensation reactions and hydrolysis reactions water is also key. It is removed from monosaccharides to enable them to join up and make long chains of molecules called polysaccharides in a condensation reaction. During a hydrolysis reaction, the water is replaced and means that plants and animals can store starch and other polysaccharides until they are needed.

Cystic Fibrosis is a disease of the exocrine glands which produces mucus. Mucus is produces all over the body, including in the lungs and reproductive organs. In the lungs the mucus traps bacteria and pathogens and is then coughed up to prevent the bacteria from causing infections. With people affects by Cystic Fibrosis, water is constantly being taken out of the mucus due to the concentrations of ions outside the cell surface membrane. This means the water travels out of the cells due to the increased water potential and leaves the mucus very thick and sticky, meaning it can’t be coughed up easily and bacteria thrive in the thick mucus. There are many other useful jobs that osmosis helps with as it regulates salt and ion levels in the body. In plants, osmosis also enables the cells to remain turgid and for the plants to remain upright.

Water is absorbed by the roots of plants and it travels up the xylem to the leaves where it is used for photosynthesis to enable the plant to growth. The water can be absorbed readily by the roots as they have a large surface area. Water has great surface tension, due to the hydrogen bonds, enabling it to travel up the stem of the plant in the xylem vessels. The water evaporates from the leaves stomata, and as it does so more water is pulled up the xylem and up into the roots due to the surface tension. The hydrogen bonds between the water molecules hold the molecules together and provide the surface tension, allowing pond skaters to survive.

Overall, water has very unique properties which make it ideal for the uses of it. No other molecule could be designed, which would improve water, as it is perfect for this world.