The water content of cells, the amount of water in living cells is generally in

Because of the different types of cells, the water content of various cells is also different. But for all kinds of life substances, water is the most important, a person can go more than ten days without eating, but not for a few days without drinking water. Therefore, water is an important substance that constitutes life and is an important component of cells, and not part of the cell is water, which is distributed in various organelles, but the water content of various cells is different.

Water is everywhere in the human body, and it is contained in cells, cells, blood vessels, and blood vessels.

The main components that make up a cell include proteins, nucleic acids, sugars, lipids, and water, which work together to form the basic unit of the living cell. Protein is one of the main building blocks of cells and can form enzymes, muscles, cell membranes, etc. Nucleic acids, including DNA and RNA, are the main carriers of genetic information in cells and participate in the genetic function of living organisms.

Sugars include monosaccharides, disaccharides and polysaccharides, which are one of the important components of cell energy supply.

Lipids are the main components of cell membranes and are also energy reserves. In addition, water is the most important solution in the cell, which can dissolve various basic substances in the cell, so that the metabolism and movement of living organisms can be carried out. The structure and function of cells depend on the organic combination of these main components, which work synergistically to build a complex and organic living system.

Introduction to Human Cells:

Human cells are the basic unit of the human body and the basis of the tissues and organs that make up it, as well as the basic unit of living organisms, and can usually only be observed under a microscope. Every cell consists of three parts: the cell membrane, the cytoplasm, and the nucleus. The cell membrane is the outer skin of the cell, which plays a role in screening the entry and exit of substances.

Cell resistance includes organelles, cytoskeleton, cell fluid, etc. The nucleus is one of the most important organs in the cell, the core of controlling life activities, and contains the genetic information of the entire human genome.

Human cells have a relatively independent metabolic system and cell membrane, which can complete the self-repair and regeneration of cells. Cells have a variety of morphologies and functions, and are classified into various types such as nerve cells, muscle cells, epithelial cells, and connective tissue cells. In order to maintain human health, cells need to get enough nutrients and oxygen**, and remove metabolic wastes and harmful substances in a timely manner, maintain normal levels of pH and osmotic pressure, and maintain the stability of the internal and external environment of cells.

Here's why:

1. Maintain the form.

1) Maintain the morphology of the cells. Only when there is enough water in the cell can the cell maintain its normal morphology, that is, to achieve its corresponding physiological functions.

2) Maintain the morphology of tissues and organs. There is both intracellular and extracellular water in tissues, and only when the amount of intracellular water and extracellular water is appropriate and balanced, can tissues maintain their normal morphology. For example, the lens of the eye, vitreous, blood, lymphatic fluid, myocardial tissue, etc. contain a large amount of water, and whether the water volume is normal directly affects the normal morphology and structure of these tissues and organs, and then affects the normal performance of their physiological functions.

2. Promote the absorption and transportation of substances by the human body.

Most nutrients and drugs need to be dissolved in water before they can be absorbed by the body, and then carried by the lymphatic circulatory system to the tissues and cells of the whole body. Excess salt, urea, carbon dioxide and other wastes are excreted from the body with the help of water and sweat, urine, etc. Hormones that regulate the body's vital activities travel with the blood to the tissues and cells of the target organs.

It is the water that makes up more than 90% of the plasma that gives the blood fluidity and drives various substances to move in the human body. Intracellular fluid, interstitial fluid, lymphatic fluid and plasma are always in a dynamic equilibrium, and the interactive flow of water among them promotes the exchange of material information between various tissues in the body.

3. Water is the medium of biochemical reactions in the human body.

Water is a good solvent and dispersion medium, and the reactants can be fully in contact with each other and the reaction substrate and enzyme in the water to promote the reaction. In addition, water can promote the ionization of various substances, which is conducive to the occurrence of reactions.

4. Participate in biochemical reactions.

In many physiological activities of the human body, water itself participates in the reaction as a reactant. For example, in the oxidation of fatty acids, in the citric acid cycle and other biochemical reactions, water is used as a reaction substrate to participate in hydration, hydrolysis, addition, redox and other reaction types.

5. Help maintain the electrolyte balance and acid-base balance of body fluids.

Intracellular fluid, organelle fluid, tissue fluid, blood, lymphatic fluid, oral cavity, gastric juice, intestinal fluid, etc., require not only the electrolyte balance composed of specific ions, but also the maintenance of a certain acid-base balance by specific ions. If the intracellular low Na+ high K+, the pH of gastric juice should be maintained at about 2, and the pH of intestinal juice should be about 7. Water acts as a buffer, and the amount of water can be adjusted, so it is important for electrolyte balance and acid-base balance.

When the human body is dehydrated, it will cause serious metabolic disorders and even threaten life.

To sum up, answer your questions.

1. Maintain the form.

2. Promote the absorption and transportation of substances by the human body.

3. Water is the medium of biochemical reactions in the human body.

4. Participate in biochemical reactions.

5. Help maintain the electrolyte balance and acid-base balance of body fluids.

At the secondary level, the water content in cells is closely related to cellular metabolism.

Water in cells exists in two forms: free water and bound water. The higher the content of free water, the more vigorous the cell metabolism; The higher the content of bound water, the less vigorous the cell metabolism.

When the seeds germinate, they first absorb water, in order to increase the content of free water and prepare for germination; When the seeds are stored, they need to be dried first, the purpose is to reduce the content of free water, so that the cell metabolism slows down, so as to reduce the loss of organic matter during storage.

Hope it helps!

Answer D Question Analysis: The amount of water in the cells is the compound that accounts for the most fresh weight, so option A is correct. The water content of a person decreases gradually over the course of a person's life, so option B is correct.

The more free water content, the more vigorous the metabolism, the weaker the stress resistance, so the drought-resistant plants have less free water content in the cells, and the C option is correct. Option d is incorrect.

Test Center: Examine the content and function of water in cells.

Comments: Pay attention to the relationship between free water and mu and combine with water function and proportion. The higher the free water content, the more vigorous the metabolism.