Water is an odorless and tasteless chemical substance that is abundant on Earth and indispensable for the survival of all living things.
Although it is often described as colorless, it has a blue color because it slightly absorbs light at red wavelengths.
In nature, water occurs in solid, liquid and gaseous states. Its chemical formula (H2O) consists of 2 hydrogen and 1 oxygen atoms.
Scientists think that life on Earth began in water. Although the molecular structure of water is quite simple and abundant, it behaves quite differently from other compounds under certain conditions. For example, water in solid (ice) state floats on liquid water. In almost all other compounds in the world, the solid phase is denser than the liquid phase and the solid phase compound sinks. This property of water has some advantages. For example, the ice layer covering the lake surface in a cold region acts as an insulator and protects the life at the bottom. If the ice collapses, living things will be exposed to severe cold, and it will be impossible for them to continue their lives.
H2O represents pure water and its compound, the closest natural example to pure water is rain water. Apart from the fact that water is fluid, the minerals it contains are very important for humans and living things. There must be various minerals in the water that living things need to drink. Rain water, that is, pure water, falls on the soil after it rains and collects the minerals in the soil, these rain water forms a stream on the earth, this is drinkable water. Minerals and their ratios are different in the soil in each region, so the benefits of water may vary by region.
İmportance of water in human life
60-70% (2/3) of an adult human body weight is water. This rate differs depending on age, gender and weight. For example, the proportion of water in the body of newborn babies is 75%. The water rate, which decreases to 70% in the first 5 days of life, gradually decreases afterwards and approaches the water rate in adults at the end of one year. The proportion of water in men is higher than in women, and fat people are more than thin people. As age progresses, there is a decrease in body water.
Water is taken into the body through digestion with foods and beverages. The water taken into the body passes into the blood after being absorbed in the digestive system. It is distributed throughout the body with the blood circulation and forms tissue fluid by leaving the capillaries. After participating in some chemical reactions inside the cell, it goes out of the cell again and turns into tissue fluid again. It enters the blood circulation from the tissues. A significant part of it comes to the kidneys through the blood circulation and is excreted out of the body as urine. Another part is used through the skin, respiratory and digestive systems and excreted from the body.
The daily water requirement of an adult is 2500-3000 ml. The intake and excretion of water occur in a balance. In order to maintain normal fluid volume in the body, daily fluid intake must be equal to daily fluid loss. When this balance is disturbed, diseases occur. You can survive for months without food, but only a few days without water. There are centers and systems that regulate the water balance in the human body.
Water intake into the body (Hydration): The intake of water to the body with foods and beverages by mouth is called exogenous water gain. In addition, as a result of chemical reactions occurring during cell metabolism in our body, water is released as an oxidation product. This release of water in the body is called endogenous water gain.
Water loss from the body (Dehydration):
The water taken into the body is thrown out of the body through the kidneys with urine, the lungs with the respiratory air, the skin through sweating, and the intestines with the stool.
1% fluid loss: feeling of thirst, deterioration of temperature regulation, decreased performance,
3% fluid loss: Body temperature deterioration, feeling of extreme thirst,
4% fluid loss: 20-30% decrease in physical performance,
5% fluid loss: Headache, fatigue,
6% fluid loss: weakness, tremor,
7% dehydration: fainting if physical activity continues,
10% fluid loss: Unconsciousness,
11% fluid loss: Body weakness, possible death,
12% fluid loss: 97% death,
15% fluid loss: 100% death.
Functions of water in the body
Carrying substances that cells need into the cell
To ensure the dissolution of the solid substances necessary for the cells to perform their functions,
Carrying the waste materials formed as a result of metabolic activities in the cells to the excretory organs (kidney, lung, skin, digestive tract) and ensuring their excretion out of the body,
Keeping the body temperature in balance,
Balancing the volume of blood,
Helping digestion of food
Facilitates O2 transfer
It is the duty of water to protect some organs such as the brain and spinal cord from external factors.