Why water is most important to living things?

Water properties that are important for animal biology (including human biology) The following are listed in no particular order, but are numbered for ease of reference: 1. Water is an excellent solvent Water is an excellent solvent. This means that many different types of materials can be dissolved in water forming solutions. Water is the solvent that carries many essential molecules and other particles through the body. These include nutrients and waste products from the body's metabolic processes. 2. Ease of movement of water molecules through biological membranes. Particles, such as some ions and molecules, must be able to move around biological organisms. One way this happens is in solutions (mentioned above), p. E.g. transporting oxygen into the blood around the vascular system. The movement of solutions within defined channels such as blood vessels and lymph vessels is easily explained by comparing it with p. the movement of fluids along the pipes. Some ions and molecules in biological organisms also need to be able to move through tissues and membranes, e.g. cell membranes. They move through the processes of diffusion, osmosis, and active transport, of which osmosis is the diffusion of water, an important process in living organisms. 3. Water is involved in many chemical reactions. Chemical reactions only occur when reagents come into contact with each other (sometimes through intermediate steps, for example, involving catalysts). Solutions are usually good "means" for chemical reactions because the solvent, p. E.g. water, encloses solutes - which could potentially be "reactive" if there is a possibility that they react to each other if and when they collide - in a common volume of space, whether it is a test tube in a laboratory or an organ or tissue in the body. When two or more potential reagents are in the same solution, they can collide and react with each other. The likelihood of this happening depends on several factors, including the concentration of the solutes, the temperature of the solution, and, in some cases, the presence (or not) of an appropriate catalyst for the reaction. Water molecules engage in decomposition reactions wherein certain macromolecules break down into smaller parts. Examples include the breakdown of carbohydrates and proteins during the digestive process. Water is also produced by chemical reactions that occur within the body in which relatively small organic compounds (called "monomers") are joined into "synthesis reactions" to form larger and more complex molecules called "macromolecules" required by the body for specific functions, e.g. nucleic acids and hormones. 4. Water can act as a lubricant, i.e. to reduce friction between moving surfaces. Water (including solutions of which water is the solvent) has an important lubrication function. This is essential in many parts of the body, especially: • in the chest and abdominal cavities, where the internal organs (for example, the heart and lungs, and organs of the digestive system) are located side by side and slide over each other as the body moves). • in the joints, p. E.g. synovial joints where structures such as bones, ligaments, and tendons need to move smoothly with each other without being hindered by friction between different structures/surfaces. 5. The thermal properties of water are well-suited to support life. Water has high specific heat. The specific heat of a substance is the quantity of heat per unit mass needed to increase the temperature of the substance by one degree Celsius. More energy is needed to increase the temperature of water compared with that of other solvents because hydrogen bonds hold the water molecules together. The definition of specific heat can be summarized as: However, the relationship expressed in the above equation does not apply if a phase change (e.g. from a liquid to a liquid) happens because heat added or removed during a phase change does not change the temperature. The specific heat of water is 4.18 J/g° C. The thermal properties of water that affect human and animal biology include: • Compared with other materials water can absorb or release a relatively large amount of heat energy while only adjusting its own temperature by a relatively small amount. Therefore the fact that water accounts for a significant proportion of body mass helps the body to cope with environmental temperature variations and maintain the body's temperature within a safe and comfortable range. • Therefore the evaporation of sweat from the surface of the skin is very efficient in helping to cool the body because it removes relatively large amounts of heat from the body as the sweat evaporates. - This also explains the limitation of fur on an animal's ability to cool itself in high temperatures, hence the use of cooling water pools by animals with dense fur living in hot climates. 5. The thermal properties of water are suitable to sustain life. The water has a specific high heat. The specific heat of a substance is the amount of heat per unit of mass needed to increase the temperature of the substance by one degree Celsius. More energy is needed to increase water temperature compared to other solvents because hydrogen bonds hold water molecules together. The specific heat definition can be summarized as: However, the relationship expressed in the above equation does not apply if a phase change occurs (for example, from a liquid to a liquid) because the heat added or removed during a phase change does not change the temperature. The specific heat of the water is 4.18 J / g. The thermal properties of water affecting human and animal biology include: • Compared to other materials, water can absorb or release a relatively large amount of thermal energy while adjusting its own temperature to a relatively small amount. Therefore, the fact that water represents a significant proportion of body mass helps the body cope with variations in ambient temperature and keep body temperature within a safe and comfortable range. • Therefore, evaporation of sweat from the skin surface is very effective in helping to cool the body because it removes relatively large amounts of heat from the body as sweat evaporates. - This also explains the limitation of fur in an animal's ability to cool itself in high temperatures, hence the use of refrigerant water pools by dense fur animals living in warm climates.