The value of water in the life of other organisms. Materials for the lesson of the outside world on the topic "Water

Water is physiologically necessary for the cytoplasm of any cell, therefore it is limiting factor both for terrestrial organisms and for those living in water, if in the latter case its amount is subject to sharp changes (ebbs and flows) or it is lost by the body in very salty water by osmotic means.

In the ground-air environment, this abiotic factor is characterized by the amount of precipitation, humidity, drying properties of the air and the available area of ​​water reserves.

The amount of precipitation depends on physical and geographical conditions and is unevenly distributed over the globe. For organisms, the most important limiting factor is the distribution of precipitation over the seasons. In temperate latitudes, even with a sufficient amount of total annual precipitation, their uneven distribution can lead to the death of plants from drought or, conversely, from waterlogging. In the tropical zone, organisms have to endure wet and dry seasons, which regulate their seasonal activity at an almost constant temperature throughout the year.

Air humidity is usually measured in terms of relative humidity (the percentage of the actual pressure of water vapor to the pressure of saturated vapor at the same temperature). The amount of humidity affects temperature effects: a decrease in humidity below a certain limit at a given temperature leads to a drying effect of the air.

The drying effect of air is most important for plants. The vast majority of plants absorb water from the soil using the root system. Desiccation of the soil makes absorption difficult. Plants adapt to the drying out of the soil by increasing the suction power and the active surface of the root system.

Water is consumed for photosynthesis, about 0.5% of water is absorbed by cells, and 97  99% of it is spent for transpiration  evaporation of water through foliage. With sufficient water and nutrients, plant growth is proportional to transpiration. The main form of plant adaptation to soil drying is not a decrease in transpiration, but a cessation of growth during a period of drought.

Depending on the methods of adaptation of plants to moisture, several environmental groups, for example: hygrophytes- terrestrial plants living in very moist soils and in conditions of high humidity (rice), mesophytes- plants capable of withstanding a slight drought (woody plants of various climatic zones, herbaceous plants of oak forests, etc.), xerophytes- plants of dry steppes and deserts. Xerophytes, in turn, are subdivided into succulents- plants capable of accumulating moisture in fleshy leaves and stems (aloe, cacti), and sclerophytes- plants with a high absorption capacity of the root system and capable of reducing transpiration due to narrow small leaves.

Among succulents, there is a phenomenon convergence- plants related to different types, have almost the same shape: African euphorbia and cactus are spherical in shape, providing a minimum evaporation surface.

Among animals in relation to water, they distinguish their environmental groups: hygrophils(hygrophilous), mesophiles- intermediate group and xerophiles(dry-loving). Methods for regulating water balance in animals are divided into behavioral, morphological and physiological.

TO behavioral ways include migration to more humid places, periodic visits to a watering hole, transition to a nocturnal lifestyle, etc. morphological ways of adaptation- devices that retain water in the body: shells of land snails, horns in reptiles, etc. Physiological adaptations provide education metabolic water, which is the result of metabolism and allows the body to do without drinking water. The latter method of adaptation is used by animals such as camels, sheep, dogs, which can withstand water losses in significant quantities (camels - up to 27%). A person dies already with a 10% loss of water. Poikilothermic animals tolerate water loss better, since they do not have to use water to cool the body, as homeothermic animals do.

The most important substance

Water- one of the most common substances on Earth. Water occupies most of the surface of our planet.
Water occurs naturally in three states: liquid, solid (ice and snow), gaseous (water vapor).
Water turns to ice at 0 degrees.
Water vapor is constantly present in the air. But it cannot be seen because it is a transparent colorless gas. It gets into the air due to the fact that water constantly evaporates from the surface of water bodies and soil.
For living organisms, water is of great importance. It is part of living organisms. Any organism constantly consumes water and needs to replenish it. Therefore, water is essential for all plants and animals. A person needs more than 2 liters of water per day.

Practical work "Investigation of the properties of water"
Purpose of work: to determine the properties of water.

Consider the equipment prepared for practical work... Use the arrows to indicate the names of the items.

Test 1... Dip a glass rod into a glass of water. Is she visible? What property of water does this indicate?
Conclusion: Water is transparent
Test 2... Compare the color of the water with the color of the stripes shown on this page. What do you see? What does this mean?


Conclusion: Water is colorless
Test 3... Smell clear water. What property of water can be established in this way?
Conclusion: Water is odorless
Test 4... Dip a flask with a tube filled with colored water in hot water. What are you watching? What does this indicate?

Conclusion: When heated, water expands
Test 5... Place the same flask in a plate with ice. What are you watching? What does this indicate?

Conclusion: When cooled, water is compressed.
General conclusion: water is transparent, colorless, odorless, expands when heated, contracts when cooled.

The most familiar and most incredible substance on Earth is water. The value of water cannot be overestimated in the life of all living things on the planet, it is present in every moment of our existence. Being the predominant element in the composition of any organism, water also controls its life.

Water in nature

Throughout its existence, humanity has been trying to unravel the mystery of this amazing and contradictory element. How did it arise, how did it get to our planet? Probably, no one will be able to answer this question, but everyone knows that the importance of water in nature and human life is unimaginably great. One thing is absolutely true - today there are as many water reserves on Earth as there was at the birth of the universe.

The unique properties of water to shrink when heated and expand when freezing are another reason to be surprised. No other substance has similar properties. And its ability to move from one state to another, so familiar and at the same time amazing, playing an exceptional role, makes it possible for all living organisms to exist on Earth. The Supreme Reason allotted the main party to water in maintaining life and participating in constantly occurring natural processes.

The water cycle

This process is called the hydrological cycle, which is a continuous circulation of water from the hydrosphere and surface of the earth into the atmosphere and then back. There are four processes involved in the cycle:

• evaporation;
• condensation;
• precipitation;
• water runoff.

Once on the ground, part of the precipitation, evaporating, condenses, the other part, due to the runoff, fills the reservoirs, the third turns into going underground. So, constantly moving, feeding waterways, plants and animals and preserving its own reserves, it wanders, protecting the Earth, water. The meaning of water is obvious and undeniable.

The circulation mechanism and its types

In nature, there is a large cycle (the so-called world), as well as two small - continental and oceanic. The precipitation collected over the oceans is carried by the winds and falls onto the continents, and then returns to the ocean with runoff. The process when ocean water constantly evaporates, condenses and falls back into the ocean in called the small oceanic circulation. And all similar processes occurring over land are combined into a small continental circulation, the main actor in which is water. Its importance in the natural processes of continuous circulation, which maintains the water balance of the Earth and ensures the existence of living organisms, is indisputable.

Water and man

Having no nutritional value in the usual sense, water is the main component of any living organism, including humans. No one can exist without water. Two-thirds of any organism is water. The value of water is extremely important for the proper functioning of all systems and organs.

Throughout life, a person comes into contact with water every day, using it for drinking and food, hygiene procedures, rest and heating. There is no one on earth
more valuable natural material, as vital and irreplaceable as water. Going without food for quite long periods of time, a person will not live without water even 8 days, since when within 8% of the body weight, fainting begins in a person, 10% cause hallucinations, and 20% inevitably cause death.

Why is water so important for a person? It turns out that water regulates all basic life processes:

• normalizes oxygen humidity, increasing its absorption;
• carries out thermoregulation of the body;
• dissolves nutrients, helping the body to absorb them;
• moisturizes and protects vital organs;
• forms a protective lubricant for joints;
• improves metabolic processes in the activity of body systems;
• promotes the evacuation of waste from the body.

How to maintain water balance

On average, a person loses 2-3 liters of water per day. In more extreme conditions, such as heat, high humidity and physical exertion, water loss increases. In order to maintain a normal physiological water balance of the body, it is necessary to balance the flow of water with its excretion by means of a competent

Let's make some calculations. Considering that the daily human need for water is 30-40 grams per 1 kg of body weight and about 40% of the total need comes from food, the rest should be taken in the form of drinks. In summer, the daily water consumption is 2-2.5 liters. Hot regions of the planet dictate their requirements - 3.5-5.0 liters, and in extremely hot conditions up to 6.0-6.5 liters of water. Do not allow dehydration of the body. Alarming symptoms of this trouble are dry skin, accompanied by itching, fatigue, a sharp decrease in concentration, blood pressure, headaches and general malaise.

Useful effect

Interestingly, by taking a direct part in metabolic processes, water contributes to weight loss. There is a common misconception that people who want to lose weight need to drink less water, since the body retains water, causing significant harm. You cannot drive your own body into even greater stress, knocking it out of the usual water exchange. In addition, moisture, being a natural diuretic, tones up kidney function, causing weight loss.

Receiving the optimal amount of water, a person adds strength, energy and endurance. It is easier for him to control weight, since even the psychological inconveniences from forced changes with a decrease in the usual diet are easier to bear. Scientific research It has been proven that daily consumption of a sufficient amount of pure water helps to fight severe ailments - it helps to relieve back pain, migraine symptoms, reduce blood sugar and cholesterol levels and blood pressure. In addition, by toning up the kidneys, water inhibits the formation of stones. It has been proven that people with a creative beginning tend to drink a lot, and great artists were pushed to create masterpieces. The meaning of water, it turns out, is also important in art.

Water exchange of plants

Just like a person, any plant needs water. In different plants, it makes up from 70 to 95% of the mass, controlling all the processes that occur. The metabolism in a plant is possible only with a large amount of moisture; therefore, the value of water for plants is undeniably great. Dissolving minerals in the soil, water delivers them to the plant, ensuring their continuous flow. Without water, seeds will not germinate, the process of photosynthesis will not take place in green leaves. The filling water ensures its vitality and preservation of a certain shape.

The most important condition for the life support of a plant organism is the ability to absorb water from the outside. The plant, receiving water, mainly from the soil with the help of the roots, delivers it to the ground parts of the plant, where the leaves evaporate it. Such a water exchange exists in every organic system - water, getting into it, gives off evaporates or is released, and then again, enriched with useful substances, enters the body.

Another amazing way of water penetration into living cells is its osmotic absorption, that is, the ability of water to accumulate from the outside into cell solutions, increasing the volume of fluid in the cell.

The art of consuming water

The constant use of pure water significantly improves the mental activity of the brain and coordination of movement, and therefore, the value of water for the vital activity of brain cells is especially valuable. That's why healthy person should not limit himself to drinking, but some rules should be followed:

• drink a little, but often;
• Do not drink a lot of water at once, as an excess of fluid in the blood will put unnecessary stress on the heart and kidneys.

So, the importance of water for living organisms is enormous. Therefore, the creation of conditions for maintaining their own water balance is necessary for every person.

Abstract open lesson around the world in grade 3.

Educational complex "Schools of Russia" (textbook by A.A. Pleshakov).

Teacher: Gerasimova Irina Sergeevna.

Topic: Water. Water properties. The value of water for living organisms.

Goals: 1. To acquaint with the basic properties of water by using various sources of information, as well as conducting simple and visual experiments;

2. Develop the ability to reason and draw conclusions based on their own observations and knowledge gained in the course of research activities;

3. To cultivate respect for environment, love for nature.

Personal UUD:

Educational and cognitive interest in new educational material;

Self-analysis and self-control of the result;

Cognitive UUD:

The ability and ability of students to perform simple logical actions (analysis, comparison);

Retrieving necessary information from various sources;

Awareness and independent construction of a speech utterance;

Self-promotion of ways to solve the problem.

Communicative UUD:

Formation of the ability to explain your choice, build phrases, answer a question, argue;

Ability to work in groups, taking into account the position of the interlocutor; organize and implement cooperation with the teacher and peers.

Regulatory UUD:

The use of sequential actions, control of the work performed;

Awareness of the level and quality of what has been learned.

During the classes.

1. Actualization of knowledge. Homework check.

Frontal poll:

What substances have we already met? (Sugar, salt, starch, acids) Which of them are the most dangerous? What are substances made of? (molecules and atoms). What is called the fifth ocean on our planet? (Air ocean). What properties of air do you know? (transparent, odorless, colorless, expands when heated, shrinks when cooled, does not conduct heat well)

Before you are the leaves. When answering questions, write down in a column: the number of the question, next to the number of the answer.

1.What happens if air disappears?

1.-nothing, 2-all plants will freeze, 3- people will think better,4-all living things will perish.

2. What gas is in the air the most?

1-oxygen ... 2-carbon dioxide, 3- nitrogen, 4-hydrogen.

3. What gas do living organisms emit when breathing?

1- oxygen , 2- hydrogen, 3- nitrogen, 4- carbon dioxide.

4.What happens when heated with air?

1-boils, 2- expands , 3- shrinks, 4- turns into water.

5. What happens to the air when it is cooled?

1- shrinks , 2- turns to ice, 3- expands, 4- clears.

6. What property of air is indicated incorrectly?

1- the air is transparent, 2- the air is odorless,3- blue air, 4-colorless.

7.Why is the air polluted?

1- schoolchildren plant trees in parks,2- the number of cars on the ground has increased,3- cleaning filters are installed in factories, 4- drivers turn off the engine when the car is parked.

8. Why are forests called “the lungs of the planet”?

1-plants breathe a lot of oxygen, 2- it is easy to breathe in forests, 3- plants purify the air from harmful gases, 4- plants emit oxygen.

9. What should be done to make the air cleaner?

1- Plant more trees and other plants, 2- in factories and plants do not use installations that capture poisonous gases, 3-use personal vehicles more often, 4- burn plastic bottles.

Self-test: I am giving the numbers of correct answers. If you have the same, then put "+". If not, then " - " . We count the number of correct answers: 9-8 is "5", 7-6 is "4", 5-4 is "3".

Leaves are handed over to the teacher.

2. Self-determination to activity.

Guess the riddle and you will find out what substance we will study in the lesson.

Inhabits the seas and rivers,
But it often flies across the sky.
And how bored she is with flying,
Falls to the ground again. (Water)

What can't you carry in a sieve? (Water)

3. Work on the topic of the lesson.

1.The teacher's story.

Look at the map. Do you think there is a lot of water on Earth? How did you guess? That's right, the seas, oceans of our planet are depicted in blue. Water occupies ¾ of the surface the globe... Water is everywhere. There is water in the air in the form of steam, fog, water is underground (springs, wells). Huge accumulations of water are located near the North and South Poles in the form of glaciers. Water is a part of any living organism and plants. In the body of animals, water makes up more than half of the body weight. For example: the body of a jellyfish is 90-95% water. There is a lot of water in the human body. Our body is almost 2/3 water.

A living organism constantly consumes water and needs to replenish it. For example, a person needs more than 2 liters of water per day (he drinks some of it, and some is contained in food). But this is not only what water is needed for. Think about where else you need water? (washing, washing, cooking, watering plants, making paper, medicine, metal, etc.) Water is the road along which ships sail. Water is electricity. She works in hydroelectric power plants.

Water is home to many animals. Some of them live in fresh water, others - in salty. Give examples.

Conclusion: If your hands are in wax,
If blots have sat down on the nose,
Who then is our first friend
Remove dirt from your face and hands?
What mom can't do without
No cooking or washing?
Without which, we will tell you straight
Should a man die?
To rain from the sky
So that ears of bread grow
To sail the ships
So that jelly is cooked,
So that there is no trouble-
We cannot live without ... (water).

2. Practical experiments and observations.

Is water important for humans? What do you need to know to use it wisely? (you need to know its properties). Do you know any properties of water? We are going to study these properties today. What sources of information can we use in this case? (books, Internet, personal and adult experience, conduct experiments, observe).

We have three groups in the class. The first group will use a computer. The second group conducts experiments No. 3, No. 4. The third group conducts experiment No. 5.

(Leaflets are distributed, on them instructions for performing each experiment. Children perform experiments, observe and attach the tablets to a magnetic board)

A note gradually appears on the board:

1. Transparent.
2. Colorless.
3. Odorless.
4. Dissolves some substances.
5. Can be cleaned.

We will consider the following experiments No. 6 and 7 in the textbook p.53. (The textbook is used as a source of information. A conclusion is made. Written on the board)

1. Expands when heated.
2. When cooled, it shrinks.

Physical education.

The next property of water you will probably tell me yourself, using your experience: if water is spilled on the floor, what will happen? Does water have a shape? What if we put water in a bottle? A vase? Saucer? What property of water will we observe?

1. Fluidity.
2. Has no form. It can take the form of a vessel.

Let's fill in the table in the notebook and draw a conclusion. What properties does water have? (When filling out the table, children briefly describe their experience and name the property they observed.)

4. Consolidation of what has been learned from a notebook. Tasks on page 22.

5. Reflection.

Let's complete the tasks in the textbook # 1, 2, 3, 4.

Raise your hands who believe they have learned a lot about water. And who thinks they have found out, but not everything? In the next lesson, we will continue our conversation about water.

6. Exhibiting marks.

7 homework... P.51 - 54 (study).

Used literature: Textbook " The world»A. Pleshakova, notebook on the world around, presentation of experiments (author Gerasimova I. S.).

Each of us has probably heard the phrase that the human body in to a greater extent consists of water. Have you ever wondered why this is so? Why do you need this a large number of liquids and in general what function does water perform in the body?

Properties

Water has the following properties:

• first of all, it is a good solvent (for both nutrients and toxic substances);
• fluidity;
• has a high heat capacity and thermal conductivity;
• may evaporate;
• is capable of hydrolyzing other substances (i.e., substances decompose under its action or are split in it).

Due to these basic properties, water performs a number of functions in the body of every living being. Let's consider them in more detail.

Functions of water in the body

The human body is, on average, 75% water. Unfortunately, this ratio changes downward with age.

Water, being the main component of all body fluids, in particular blood, which contains more than 90% of it, performs the following main functions:

• regulation of body temperature;
• removal of toxins, and;
• transport of nutrients and oxygen;
• assimilation and digestion of food;
• transport function;
• amortization of joints and prevention of their friction;
• maintenance of cell structures;
• protection of tissues and internal organs;
• improving metabolism.

The functions of water in thermoregulation processes are to ensure a constant body temperature for cellular level by evaporation and perspiration. Due to its ability to carry a sufficiently large amount of moisture, circulating in human body, takes it where it is in surplus, and adds it where it is not enough.

The shock-absorbing functions of water in the body are provided due to its high content in the synovial fluids of the joints. This prevents friction of the articular surfaces during stress and work of the joints, and also serves as a certain protective buffer against possible falls and injuries.

Water performs the function of transporting the necessary compounds due to its large. Thus, it can penetrate everywhere, even into the intercellular spaces, delivering the necessary organs and tissues and removing their waste products.

It is generally accepted that the amount of fluid consumed directly depends on mental dehydration. Dehydration threatens not only with a decline in strength, energy, headaches and dizziness, but also with a decrease in efficiency, memory and the ability to concentrate on the necessary information.

Also, given that with age, the amount of water as a component of the body decreases, scientists assume a certain relationship between the amount of fluid and aging processes. Therefore, older people age group you need to be especially careful about the water diet.

V last years more and more often the functions of water are noted in the prevention of many diseases, including cancer. It is believed that the more fluid we consume, the more it is excreted, and with it disease-causing organisms, their waste products, toxins, and which can potentially be a springboard for the development of cancer.

Thus, all functions of water are important for the normal functioning of all organs and systems and for a comfortable and healthy lifestyle of a person.

The less water comes from outside, the more it accumulates inside. This means that if you drink liquid irregularly and in insufficient quantities, then at the next intake of it, the body retains water, keeping it as if in reserve. Thus, a person not only exposes himself to a number of diseases with his own hand, but also gains excess weight.

The first signal that your body gives about a lack of water is the well-known fatigue. If long time not to compensate for the physiological loss of fluid, then the person begins to feel aching in the joints and discomfort in the spine. Toxins accumulate in the body, immunity decreases, and a person becomes more susceptible to diseases, especially infectious ones.

Important!

You need to consume 1.5-2 liters of liquid daily. Regular intake of high-quality water will give you a feeling of a surge of strength and vigor, digestion processes will improve, headaches and other uncomfortable sensations will no longer bother you. Not only will you feel better, you will definitely look better.

Conclusion

The functions of water in the human body are varied and numerous. Therefore, you should not neglect such an important part of your diet. Drink water in the required amount and be healthy!