Literally from childhood, everyone knows that water plays a very important role for us. Hygiene, cleaning, drinking - each of these integral elements of life is associated with water. Studying the world gradually, the child learns about the role of water in the cell. Perhaps, only from this moment does it become clear how great its significance is: life itself is unthinkable without water. Due to its properties, it makes possible the functioning of complex organisms.
Molecule structure
The role of water in the life of a cell is directly related to the features of its structure. Everyone knows the formula of the main fluid of our body. Each water molecule consists of one oxygen atom and two hydrogen atoms. They are combined into a single whole due to polar covalent bonds based on the formation of a common electron pair in two atoms. A characteristic feature of water molecules is its electrical asymmetry. The oxygen atom is more electronegative, it attracts the electrons of hydrogen atoms more strongly. The consequence of this is the shift of the common pairs of electrons towards the oxygen atom.
Dipole
The role of water in the cell depends on the characteristics inherent in this substance. As a result of the displacement of the common pair of electrons, it becomes polarized. A water molecule is characterized by the presence of two poles: each hydrogen atom has a partially positive charge, and oxygen has a partially negative charge. Together they create a neutral molecule.
Thus, each structural unit of water is a dipole. A structural feature of the molecule also determines the nature of the bond between neighboring structures. A partially negative oxygen atom is attracted by the hydrogen atoms of other molecules. Between them, the so-called hydrogen bonds are formed. Each water molecule seeks to communicate in this way with its four neighbors. All of the nuances of the structure mentioned determine the biological role of water in the cell.
Features
Hydrogen bonds characteristic of water molecules determine many of its properties. The compounds between the oxygen and hydrogen atoms are particularly strong, that is, in order to break them, you need to spend an impressive amount of energy. As a result, water has a high boiling point, as well as melting and vaporization. Among similar substances, water is the only substance present on the Earth simultaneously in three states of aggregation. What the role of water in the cell is based on is its particularity.
Interaction with hydrophilic substances
The inherent ability of water particles to form hydrogen bonds allows the body’s main body fluid to dissolve many compounds. Such substances are called hydrophilic, that is, "friendly" to water. These include ionic compounds: salts, bases and acids. Among the hydrophilic substances are nonionic compounds having polarity. Their molecules contain charged groups. These are amino acids, sugars, simple alcohols and some other compounds.
The role of water in the life of the cell is reduced to creating the environment necessary to accelerate all reactions. A solution is a state of matter in which all its molecules can move much more freely, that is, the ability to enter into a reaction becomes much higher than in its usual form.
Due to its properties, water has become the main medium for the course of the vast majority of chemical reactions. Moreover, for example, hydrolysis and the whole set of redox processes are carried out only with the direct participation of the main cell fluid.
Reagent
The huge role of water in the life of the cell is undeniable. She is involved in all important processes. For example, water is needed for photosynthesis. One of its stages, the photolysis of water, consists in the separation of hydrogen atoms and their inclusion in the resulting organic compounds. At the same time, released oxygen is released into the atmosphere.
The role of water in the cell of humans and animals is associated with the already mentioned hydrolysis, the destruction of substances with the addition of water. One of the most important reactions of this kind in the cell is the breakdown of the ATP molecule, which occurs with the release of energy, which is used for other vital processes.
Interaction with hydrophobic substances
Some proteins, as well as fats and nucleic acids do not dissolve in water at all, or this process is very difficult. Such substances are called hydrophobic, that is, “afraid” of water. The role of water in the cell and the body is also associated with its interaction with similar compounds.
Water molecules are able to separate hydrophobic substances from the liquid itself. As a result, so-called interface surfaces are formed. Many chemical reactions are carried out on them. So, it is precisely due to the interaction of the phospholipids that make up the cell membrane with the formation of a lipid bilayer.
Heat capacity
The biological role of water in the cell lies in its participation in thermoregulation. The heat capacity of water is quite high. This means that when an impressive amount of thermal energy is absorbed, the temperature of the water changes slightly. Such its characteristic contributes to maintaining a constant temperature inside the cell, which is necessary for the normal course of many processes and maintaining the constancy of the internal environment.
Uniform heat distribution
Another characteristic feature of water is thermal conductivity. It also helps to maintain a constant internal environment. Water is capable of transferring an impressive amount of heat from the area of the body where it is in abundance to those cells and tissues that lack it.
In addition, thermoregulation is carried out due to the evaporation of water. Cooling occurs due to the fact that upon transition from one state of aggregation to another, hydrogen bonds must be destroyed. And for this, as already mentioned, high energy costs are required.
Hydrostatic skeleton
The role of water in cell life does not end there. The main body fluid has another property: it practically does not shrink. This characteristic allows water to play the role of a hydrostatic skeleton in the cell. Water creates turgor pressure, thereby determining the properties of cells and tissues, such as bulkiness and elasticity. It is easy to understand what is the role of water in the cell in this sense, if you look at the trees. The habitual shape of the leaves is created due to increased pressure in the cells. There are many similar examples in the organic world. For example, the familiar jellyfish or roundworm shape is also supported by a hydrostatic skeleton.
Loss of water by cells, respectively, leads to reverse processes. The change in shape begins: the leaves fade, the fruits shrink, the skin loses elasticity.
Participation in the transport of substances
Water molecules with the help of hydrogen bonds are able to connect not only with each other, but also with other substances. As a result of this interaction, surface tension appears , which plays a significant role in the transport of substances in the body. So, a consequence of cohesion (cohesion of molecules by gravity, and in the case of water, by means of hydrogen bonds) is the movement of nutrients in the capillaries of plants. Due to the same property, water enters from the soil through the root hairs into the plant.
Also, the force of surface tension makes capillary blood flow possible in animals and humans. Water is involved in the movement of substances and excretion of decay products from the body.
It turns out that the answer to the question "what is the role of water in the cell?" quite straightforward - it is huge. Due to the basic properties of the molecular structure of this liquid, all the basic processes are possible, without which life is unthinkable. Water helps increase the reactivity of substances, maintains the shape of cells and organs, participates in providing them with everything necessary, is part of many chemical reactions. Water is the source of life, and it is definitely not a metaphor. All the main metabolic processes associated with it, it also lies at the heart of the interaction of various compounds.
It is because of such properties that water is the substance that is sought primarily during the study of other planets in an attempt to understand whether they are suitable for life.