Biology project on bacteria. Bacteria - Enemies to me or friends? Research work Creative work of students on biology (Grade 6) on the topic

Project study "Bacteria: Friends or Enemies?" Authors: Pupils 5 A Class of Perseva V. Sabanina S. Dorokhova A. Lapshinova and year

Bacteria decomposition and rotting 1. Bacteria - the link of the substances in nature. They decompose sophisticated substances On simple, which are used by plants. 2. Bacteria - Sanitars of our planet. Feeding organic substances of dead plants and animal corpses, they turn them into humus. 3. Some bacteria make products unsuitable for nutrition. 4. There are bacteria that spoil fishing nets, manuscripts and books, hay in stacks, etc.

Soil bacteria 1. There are bacteria that convert humus to minerals. 2. Some soil bacteria absorb nitrogen from the air. 3. These are nitrogen-free bacteria. 4. They form nitrogen compounds that use plants.

Measures to prevent infectious diseases 1. Strict medical control over water sources and food products. 2. The water is purified in special sumps, passing through the filters, chlorized, ion. 3. Patients receive medicines that kill pathogenic bacteria 4. Indoors are disinfected. 5. In order to prevent diseases, vaccinations are used.

Conclusion 1. Bacteria play a large role in the nature and life of a person. 2. There are bacteria decomposition and rotting, soil and pathogenic bacteria. 2. Bacteria can bring both benefits and harm. 3. Bacteria for humans are both friends and enemies.

Bacteria is the most ancient group of organisms from now existing on Earth. The first bacteria appeared, probably more than 3.5 billion years ago and for almost a billion years have been the only living creatures on our planet. Since these were the first representatives of wildlife, their body had a primitive structure.

Over time, their structure was complicated, but also the bacteria is considered the most primitive single-cell organisms. Interestingly, some bacteria and now have now retain the primitive features of their ancient ancestors. This is observed in bacteria living in hot sulfur sources and oxless flashes at the bottom of the reservoirs.

Most bacteria colorless. Only a few are painted in purple or in a green color. But the colonies of many bacteria have bright coloringwhich is determined by the release of the painted substance in environment or cell pigment.

The plaque of the world of bacteria was Anthony Levenguk - the Dutch natural backs of the 17th century, which first created the perfect magnifying glass microscope, increasing items 160-270 times.

Bacteria refer to prokarytams and isolated into a separate kingdom - bacteria.

Body shape

Bacteria are numerous and varied organisms. They differ in shape.

Bacteria name	Shape bateria	Image of bacteria
Cockki.		Sharo-shaped
Bacillus		Chopkoid
Vibrio		Semiconde
Spirillum		Spiraloid
Streptococci		Cockkk chain
Staphilococci		Breakdi Cockkn.
Diplococci		Two round bacteria enclosed in one mucous capsule

Methods of movement

Among bacteria there are movable and fixed forms. Movable moves due to wave-like cuts or with the help of flagellas (twisted screw threads), which consist of a special flask of flagellin. The flagellas may be one or more. They are located in some bacteria at one end of the cell, others - on two or all over the surface.

But the movement is inherent in many other bacteria that there are no flavors. Thus, bacteria covered with mucus outside are capable of sliding movement.

Some devoid harvesters of aquatic and soil bacteria in the cytoplasm there are gas vacuoles. The cell can be 40-60 vacuoles. Each of them is filled with gas (presumably - nitrogen). Adjusting the amount of gas in vacuoles, water bacteria can be immersed in the thickness of the water or rise to its surface, and soil bacteria - move in soil capillaries.

Habitat

Due to the simplicity of the organization and unpretentiousness of the bacteria are widespread in nature. The bacteria were found everywhere: in a drop of even the most pure spring water, in the tillage grains, in the air, on the rocks, in the polar snow, the sands of the desert, at the ocean day, in the huge depth of oil and even in the water of hot springs with a temperature of about 80ºС. They live on plants, fruits, in various animals and in humans in the intestine, oral cavity, on the limbs, on the body surface.

Bacteria are the smallest and most numerous living beings. Thanks to small sizes, they easily penetrate any cracks, slits, pores. Very hardy and adapted to various conditions of existence. Turn the drying, strong cold, heating up to 90 ° C, without losing the viability.

There is practically no place on earth where bacteria would not meet, but in different quantities. The living conditions of bacteria are diverse. One of these requires air oxygen, others do not need it and are able to live in an oxygenous medium.

In the air: bacteria rise to the upper atmosphere of up to 30 km. and more.

Especially many of them in the soil. In 1, the soil may contain hundreds of millions of bacteria.

In water: in the surface layers of water of open reservoirs. Useful water bacteria mineralize organic residues.

In living organisms: pathogenic bacteria fall into the body from the external environment, but only in favorable conditions causing the disease. Symbiotic live in digestion organs, helping to split and absorb food, vitamins synthesize.

External structure

The bacteria cell is dressed by a special dense sheath - a cell wall that performs a protective and reference function, and also gives bacteria a constant characteristic of her form. The cell wall of the bacteria resembles a vegetable cell shell. It permeates: through her nutrients freely pass into the cage, and the metabolic products are entering the environment. Often over the cell wall in the bacteria, an additional protective layer of mucus - capsule is produced. The thickness of the capsule can increase the diameter of the cell itself many times, but maybe very small. Capsule is not a mandatory part of the cell, it is formed depending on the conditions in which bacteria fall. It protects the bacterium from drying.

On the surface of some bacteria there are long flagellas (one, two or many) or short thin veins. The length of flags can many times to exceed the bacterium bodies. With the help of flagella and vigor, bacteria move.

Internal structure

Inside the bacteria cell is a thick fixed cytoplasm. It has a layered structure, there are no vacuoles, therefore various proteins (enzymes) and spare nutrients are placed in the substance of the cytoplasm. Bacteria cells do not have a kernel. In the central part of their cells concentrated substance carrier hereditary information. Bacteria, - nucleic acid - DNA. But this substance is not decorated in the core.

The internal organization of the bacterial cell is complex and has its own specific features. The cytoplasm is separated from the cell wall of the cytoplasmic membrane. In the cytoplasm there is a basic substance, or matrix, ribosomes and a small number of membrane structures that perform a variety of functions (mitochondrial analogues, an endoplasmic network, a Golgi apparatus). In the cytoplasm of bacteria cells often contain granules of various shapes and sizes. Granules can consist of compounds that serve as a source of energy and carbon. In the bacterial cell there are and fat droplets.

In the central part of the cell, the nuclear substance is localized - DNA, not degraded from the cytoplasm of the membrane. This is an analogue of the nucleus - nucleoid. The nucleoid does not have a membrane, a nuclear fuel and a set of chromosomes.

Methods of nutrition

Bacteria observed different ways of nutrition. Among them are autotrophic and heterotrophs. Avtotrophs are organisms capable of independently form organic substances for their power.

Plants need nitrogen, but they themselves absorb air nitrogen. Some bacteria connect the nitrogen molecule contained in the air with other molecules, resulting in substances available for plants.

These bacteria settle in the cells of young roots, which leads to formation on the roots of thickening, called non-naval. Such tubers are formed on the roots of plants of the family of legumes and some other plants.

The roots give carbohydrate bacteria, and the bacteria roots are such nitrogen substances that can be assimilated by the plant. Their cohabitation is mutually beneficial.

Roots of plants allocate many organic substances (sugar, amino acids and others) powered by bacteria. Therefore, in a layer of soil surrounding the roots, especially many bacteria are settled. These bacteria turn outmended plant residues into a substance available for the plant. This layer of the soil is called the rhizosphere.

There are several hypotheses about penetration of nodule bacteria in the root fabric:

• through damage to the epidermal and cow fabric;
• through root hairs;
• only through a young cell shell;
• thanks to bacteria satellites producing pectinolytic enzymes;
• due to the stimulation of the synthesis of in-indolyluxusic acid from tryptophan, always existing in the root discharge of plants.

The process of introducing nodule bacteria into the root fabric consists of two phases:

• infection of root hairs;
• the process of the formation of the tuber.

In most cases, the introduced cell, actively multiplies, forms the so-called infectious threads and is already in the form of such threads moved to the tissue of the plant. Nodule bacteria that came out of the infectious thread continue to multiply into the host fabric.

Fulled vegetable cells, filling with rapidly multiply cells, begin to share hard. The connection of the young tuber with the root of the leggings is carried out thanks to vascular fibrous beams. During the functioning of the tubers are usually dense. By the time of the manifestation of the optimal activity, the muscles acquire a pink color (thanks to the pigment LeggoLobin). Only those bacteria that contain legglobin are capable of fixing nitrogen.

The bacteria of the tubers create dozens and hundreds of kilograms of nitrogen fertilizers on the hectare of soil.

Metabolism

Bacteria differ from each other metabolism. In some, it goes with the participation of oxygen, others - without his participation.

Most bacteria feed on ready-made organic substances. Only some of them (blue-green, or cyanobacteria) are capable of creating organic substances from inorganic. They played an important role in the accumulation of oxygen in the atmosphere of the Earth.

Bacteria absorb substances from outside, tear their molecules to pieces, from these parts they collect their shell and replenish their contents (so they grow), and unnecessary molecules are ejected out. The shell and membrane of the bacteria allows it to absorb only the necessary substances.

If the shell and membrane bacteria were completely impenetrable, no substances would fall into the cage. If they were permeable for all substances, the contents of the cell would be mixed with the medium with a solution in which bacterium lives. For the survival of the bacteria, a shell is necessary, which the necessary substances skips, and unnecessary - no.

Bacteria absorbs nourishing substances nearby. What happens later? If she can move independently (moving a flagellum or pushing back the mucus), then it moves until the necessary substances find.

If it cannot move, it is waiting for the diffusion (the ability of the molecules of a substance to penetrate into the thick of the molecules of another substance) will not bring the necessary molecules to it.

Bacteria in aggregate with other groups of microorganisms perform tremendous chemical work. Turning various compounds, they get energy and nutrients needed for their lively. The metabolic processes, methods of extracting energy and the need for materials for the construction of substances of their body in bacteria are diverse.

Other bacteria All carbon needs needed to synthesize organic matter bodies are satisfying due to inorganic compounds. They are called autotrophs. Auto-flow bacteria are able to synthesize organic substances from inorganic. Among them are distinguished:

Chemosynthesis

The use of radiant energy is the most important, but not the only way to create an organic substance from carbon dioxide and water. Known bacteria that are not solar light as a source of energy for such synthesis, but energy chemical tiesoccurring in organisms in the oxidation of some inorganic compounds - hydrogen sulfide, sulfur, ammonia, hydrogen, nitric acid, acidic compounds of iron and manganese. The organic substance formed using this chemical energy is used to build cells of their body. Therefore, such a process is called chemosynthesis.

The most important group of chemosynthetic microorganisms is nitrifying bacteria. These bacteria live in the soil and carry out the oxidation of ammonia formed during the rotation of organic residues to nitric acid. The latter, reacts with the mineral compounds of the soil, is converted into nitric acid salts. This process takes place in two phases.

Jamming is converting zakuzny iron into the oxide. The formed iron hydroxide settles and forms the so-called marsh iron ore.

Some microorganisms exist due to the oxidation of molecular hydrogen, thereby ensuring the authotrophic power method.

A characteristic feature of hydrogen bacteria is the ability to switch to a heterotrophic lifestyle while providing them with organic compounds and the absence of hydrogen.

Thus, chemoautotrophs are typical autotrops, as they are independently synthesized from inorganic substances Required organic compounds, and do not take them in the finished form from other organisms as heterotrophs. From phototrophic plants, chemoavtotrophic bacteria differ in complete independence from light as an energy source.

Bacterial photosynthesis

Some pigment-containing serobacteria (purple, green), containing specific pigments - bacteriochlorophylls, are able to absorb solar energy, with which hydrogen sulfide in their organisms split and gives hydrogen atoms to restore the corresponding compounds. This process has a lot in common with photosynthesis and is only distinguished by the fact that purple and green bacteria donor hydrogen is hydrogen sulfide (occasionally - carboxylic acids), and in green plants - water. For those and other cleavage and transfer of hydrogen due to the energy of the absorbed sunlight.

Such bacterial photosynthesis, which occurs without the release of oxygen, is called photoreduction. The photo generation of carbon dioxide is associated with the transfer of hydrogen not from water, but from hydrogen sulfide:

6SO 2 + 12N 2 S + HV → C6H 12 O 6 + 12S \u003d 6N 2 O

The biological importance of chemosynthesis and bacterial photosynthesis across the planet is relatively small. Only chemosynthetic bacteria play a significant role in the process of sulfur circulation in nature. Absorbing green plants in the form of salts of sulfuric acid, sulfur is restored and included in the composition of protein molecules. Next, in the destruction of dead vegetative and animal residues, sulfur with sulfide, which is oxidized by sulfide sulfide, which is oxidized by sulfur-free sulfur (or sulfuric acid), sulfite-free in soil. Chemo and photoauthotrophic bacteria are essential in the cycle of nitrogen and sulfur.

Sporing

Inside the bacterial cell disputes are formed. In the process of sporing, the bacterial cell undergoes a number of biochemical processes. It decreases the amount of free water, enzymatic activity is reduced. This ensures the stability of the dispute to the adverse conditions of the outer environment (high temperature, high saline concentration, drying, etc.). Sponges are typical only by a small group of bacteria.

Disputes - not mandatory stage life cycle bacteria. Sponge formation begins only with a lack of nutrients or accumulation of exchange products. Bacteria in the form of dispute can for a long time To be at rest. Spores of bacteria withstand long-term boiling and very long-term industrialization. Upon the occurrence of favorable conditions, the dispute germinates and becomes viable. Conference bacteria is a device for survival in adverse conditions.

Reproduction

Bacteria is multiplied by the division of one cell into two. Having achieved a certain size, bacterium is divided into two identical bacteria. Then each of them begins to eat, grows, it is divided and so on.

After lengthening the cell, the transverse partition is gradually formed, and then daughter cells diverge; In many bacteria, at certain conditions, the cells after division remains associated in characteristic groups. In this case, depending on the direction of the plane of division and the number of divisions, different forms occur. The reproduction of the kill is found in bacteria as an exception.

Under favorable conditions, cell dividing in many bacteria occurs every 20-30 minutes. With such a rapid reproduction, the offspring of one bacterium in 5 days is able to form a mass that can fill all seas and oceans. A simple calculation shows that 72 generations (720,000,000,000,000,000,000 cells) can be formed during the day. If we translate into the weight - 4720 tons. However, this does not occur in nature, since most bacteria die quickly under the action sunlight, when drying, disadvantage of food, heating to 65-100ºС, as a result of the struggle between the species, etc.

Bacteria (1), absorbed enough food, increases in size (2) and begins to prepare for reproduction (cell division). Its DNA (in the bacteria of the DNA molecule is closed in the ring) doubles (bacterium produces a copy of this molecule). Both DNA (3,4) molecules are attached to the bacterium wall and the bacterial lengthening is diverged on the parties (5.6). First divides nucleotide, then cytoplasm.

After the discrepancy between the two DNA molecules on the bacteria, a hauling appears, which gradually separates the body of the bacterium into two parts, in each of which there is a DNA molecule (7).

It happens (in a hay stick), two bacteria sticks out, and a jumper is formed between them (1.2).

On the jumper DNA from one bacterium is transferred to another (3). Called in one bacterium, DNA molecules are flying, sticking together in some places (4), after which they exchange areas (5).

The role of bacteria in nature

Crooked

Bacteria is the most important link of the total cycle of substances in nature. Plants create complex organic substances from carbon dioxide, water and mineral soil salts. These substances are returned to the soil with extreme mushrooms, plants and animal corpses. Bacteria decompose complex substances on simple, which again use plants.

Bacteria destroy complex organic substances of dead plants and animal corpses, allocating living organisms and different garbage. Feeding by these organic substances, the saprophistic bacteria of rotting turn them into humus. These are peculiar socitars of our planet. Thus, bacteria are actively involved in the cycle of substances in nature.

Soil formation

Since bacteria are spread almost everywhere and are found in a huge amount, they largely determine the various processes occurring in nature. In the fall, the leaves of trees and shrubs fall, the overhead feces of herbs die, fall out of the old branches, falling from time to time the trunks of old trees fall. All this gradually turns into humus. In 1 cm 3. The surface layer of forest soil is contained hundreds of millions of saprophistic soil bacteria of several species. These bacteria are converted by humus in various minerals that can be absorbed from the soil roots of plants.

Some soil bacteria can absorb nitrogen from the air using it in the processes of vital activity. These nitrogen-free bacteria live independently or settled in the roots of legume plants. Penetrating in the roots of legumes, these bacteria cause the growth of the roots cells and the formation of nodule on them.

These bacteria isolated nitrogen compounds that use plants. Bacteria from plants are obtained carbohydrates and mineral salts. Thus, there is a close relationship between the beam and nodule bacteria, useful for both one and other organism. This phenomenon is called symbiosis.

Thanks to symbiosis with nodule bacteria, legumes enrich the soil with nitrogen, contributing to raising the harvest.

Distribution in nature

Microorganisms are distributed everywhere. The exception is only the craters of the active volcanoes and small sites in the epicenters of blown atomic bombs. No low temperatures of Antarctic, nor boiling jets of geysers, nor saturated solutions of salts in hydrochloric basins, nor strong insolation of mountain peaks, nor the hard irradiation of atomic reactors interfere with the existence and development of microflora. All living beings constantly interact with microorganisms, being often not only by their storage facilities, but also by distributors. Microorganisms are the aborigines of our planet, actively mastering the most incredible natural substrates.

Microflora soil

The number of bacteria in the soil is extremely large - hundreds of millions and billion individuals in 1 gram. In the soil they are much larger than in water and air. The total number of bacteria in soil changes. The number of bacteria depends on the type of soil, their states, the depth of the layer.

On the surface of soil particles, microorganisms are located small microcoltones (20-100 cells each). Often they develop in the thickness of the bunches of organic matter, on the living and dying roots of plants, in thin capillaries and inside the lumps.

The soil microflora is very diverse. There are different physiological groups of bacteria: bacteria of rotting, nitrifying, nitrofixing, serobacteria, etc. Among them are aerobes and anaerobes, disputes and not disputes. Microflora is one of the factors of soil formation.

The area of \u200b\u200bdevelopment of microorganisms in the soil is a zone adjacent to the roots of living plants. It is called the rhizosphere, and the aggregate of microorganisms contained in it - the rhizosphere microflora.

Microflora reservoirs

Water - natural environmentwhere microorganisms develop in large numbers. The bulk of them enters the water from the soil. A factor determining the amount of bacteria in water, the presence of nutrients in it. The most pure are the water of artesian wells and spring. Very rich in bacteria open reservoirs, rivers. The greatest number Bacteria is located in the surface layers of water, closer to the shore. When removing from the shore and increasing depth, the number of bacteria decreases.

Clean water contains 100-200 bacteria in 1 ml., And contaminated - 100-300 thousand and more. Many bacteria in the bottom Ile, especially in the surface layer, where the bacteria form the film. In this film, there are many seroids and ferrucks, which oxidize hydrogen sulfide to sulfuric acid and thereby prevent the fish to the fisher. In Ile more sporing forms, while in the water predominantly dominated.

According to the specified composition of the water microflora is similar to the microflora soil, but there are also specific forms. Destroying various garbage in the water, microorganisms gradually carry out the so-called biological purification of water.

Microflora air

Air microflora is less numerous than soil microflora and water. Bacteria rise into the air with dust, some time can be there, and then settle on the surface of the Earth and die from lack of nutrition or under the action of ultraviolet rays. The number of microorganisms in the air depends on geographical zone, terrain, time of year, polluted dust and others. Each dust is a carrier of microorganisms. Most of the bacteria in the air over industrial enterprises. Air countryside cleaner. The most clean air over the forests, mountains, snow spaces. The upper air layers contain fewer microbes. In the air microflora, many pigmented and sporing bacteria, which are more resistant than others, to ultraviolet rays.

Microflora of the human body

The human body, even completely healthy, is always a carrier of microflora. When contacting the body of a person with air and soil on clothes and skin, a variety of microorganisms, including pathogenic (tetanus sticks, gas gangrenes, etc.) are seen. Open parts are most often contaminated. human body. In the hands of intestinal sticks, staphylococcis are found. In the oral cavity there are over 100 types of microbes. The mouth with its temperature, humidity, nutritional residues is an excellent environment for the development of microorganisms.

The stomach has an acidic reaction, so the bulk of microorganisms in it is dying. Starting from the subtle intestine, the reaction becomes alkaline, i.e. Favorable for microbes. In the thick intestines of the microflora is very diverse. Each adult highlights every day with excrement about 18 billion bacteria, i.e. More individuals than people on the globe.

Internal organs that are not connected with the external environment (brain, heart, liver, bladder, etc.), usually free from microbes. In these organs, microbes fall only during the disease.

Bacteria in cycle of substances

Microorganisms in general and bacteria in particular play a large role in biologically important cyphans of substances on Earth, carrying out chemical transformations that are completely inaccessible neither by plants or animals. The various stages of the cycle of elements are carried out by organisms of different types. The existence of each individual group of organisms depends on the chemical transformation of the elements carried out by other groups.

Crack of Nitrogen

The cyclic transformation of nitrogen compounds plays a paramount role in supplying the necessary forms of nitrogen of various food needs of the biosphere organisms. Over 90% of the total nitrogen fixation is due to the metabolic activity of certain bacteria.

Create carbon

Biological conversion of organic carbon in carbon dioxideaccompanied by the restoration of molecular oxygen requires the joint metabolic activity of a variety of microorganisms. Many aerobic bacteria exercise full oxidation organic substances. In aerobic conditions, organic compounds are initially split off by saving, and organic finite fermentation products are further as a result of anaerobic breathing if there are inorganic hydrogen acceptors (nitrate, sulfate or CO 2).

Circular sulfur

For living organisms, sulfur is mainly available in the form of soluble sulfates or reduced organic sulfur compounds.

Crooked Iron.

In some reservoirs with freshwater Contained in high concentrations reduced iron salts. In such places, a specific bacterial microflora is developing - barrels, oxidizing reduced iron. They participate in the formation of marsh iron ore and water sources rich in iron salts.

Bacteria are the most ancient organisms that appeared about 3.5 billion years ago in Archeye. About 2.5 billion years, they dominated the Earth, forming the biosphere, participated in the formation of an oxygen atmosphere.

Bacteria are one of the most simply arranged living organisms (except for viruses). It is believed that they are the first organisms that appeared on Earth.

Popova Veronica

Project Manager:

Elizarova Galina Ivanovna

Institution:

GKOU Volgograd Sanatorium school - boarding school "Hope"

In the presented research project on biology "bacteria" For grade 5, the author studies the types of bacteria, their impact on the human body, and also conducts the survey of classmates. The work contains reference material about bacteria and a description of practical experiments conducted by the author.

In the process of working on research project According to biology on the topic "Bacteria" The 5th grade students were set to explore bacteria living in the human body and reproduction of bacteria at home.

The basis of research work on biology on the theme "bacteria" is the analysis of theoretical information about the origin and types of bacteria, and the survey of students on the subject of acquaintance with the types of bacteria, their habitat and interaction with the human body is carried out.

In the proposed project on Biology "Bacteria" According to the 5th grade, the author of the theoretical data on the peculiarities of the influence of bacteria on human health, and practical experiments of the reproduction of bacteria at home were carried out.

Some materials of this project on biology "bacteria" can be used in 3 and 4th grade, as well as in 6 and 7 school classes as additional material To the lesson.

Introduction
1. Varieties of bacteria.
1.1 Lactobacilli.
1.2 Defender of the Puz.
1.3 Heat.
1.4 running.
2. Questioning.
3. Experiments on the reproduction of bacteria at home.
Conclusion
Literature

Introduction

Bacteria - The smallest living creatures that can be found in any corner of the globe.
They were found in jets of geysers with a temperature of about 105, over salty lakes, for example, in the famous Dead Sea. Live bacteria were found in the eternal Merzlot of the Arctic, where they spent 2-3 million years.

In the ocean, at a depth 11km; at an altitude of 41km in the atmosphere; In the depths earth crust At the depth of several kilometers - everywhere found bacteria. Bacteria feel perfectly in water, cooling nuclear reactors; remain viable, having received a dose of radiation at 10 thousand times greater than fatal for humans.

Tasks:

• Find out what bacteria are.
• Perform experiments on reproduction of bacteria at home.
• Analyze information about bacteria.

Object of study - Bacteria.

Subject of study - The value of bacteria for a person.

Work methods:

• Experiments
• Observations
• Analysis of relevant literature

Relevance: The world of bacteria is part of our life.

Bacteria play a very important role in the world of living. Bacteria were one of the first, appeared on the land of species (they appeared about 4 trillion years ago), and more than probably they will survive us, people.

Despite their huge variety and that they are resettled almost everywhere on earth - and at the bottom of the ocean, and even in our intestine, - the bacteria still has something in common. All bacteria have approximately the same size (several micrometers).

Project on biology on the topic: "The role of lactic acid bacteria in a person's life." The work was carried out by: Gudkov Margarita Frejalov Anna Project Manager: Pimenova N. G. April 2011, MOU SOSH No. 42 P. Reshetich Volodarsky district of the Nizhny Novgorod Region

The goal of the project: Find out the importance and role of lactic acid bacteria in nutrition and human life. Project tasks: explore the role of microbiology as science; emphasize the importance of microbiology in the creation of fermented milk products; consider the action of lactic acid bacteria on the gastrointestinal tract; Find out the percentage ratio of the consumption of fermented milk products by various groups of the population; Give recommendations for the consumption of dairy products

1. Introduction of bacteria Use in the chemical industry Food production Production of antibiotics Participation in the cycle of substances Production of hormones, antigens, antibodies and other proteins The role of lactic acid bacteria

It is achieved: the plasticity of metabolism. The ability to adapt environmental friendliness is a huge mass of products consumed by us are bioproducts. A very long time, the person forced the bacteria, yeast and other microorganisms. In connection with the development of industrial microbiology, intensive selection work is underway to eliminate the strains of microorganisms with increased productivity of substances necessary for a person. "Large" microorganisms produced most of the diverse products. Local bacteria (Louis Pasteur) Milk Acid in its presence is not able to develop rotten microbes "Microorganism" This is a malaeheline individual

2.2 Products containing lactic acid bacteria and bifidobacteria Such milk products Kefir Ryazhenka Sour cream Cottage cheese yogurt Prostokvash

2.3 Use of products with various groups of the population students MOU SOSH No. 42

2.4. The role of lactic acid bacteria and bifidobacteria. Reducing the number of bifidobacteria leads to: long-term intestinal infections in children and adults; Violation of protein and fat metabolism; Impaired mineral exchange; Violation of intestinal suction processes; The formation of chronic intestinal disorders of digestion. Maintaining and normalizing the intestinal microbiocenosis; Improving protein, vitamin and mineral exchange (are the "supplier" of a number indispensable amino acids, including tryptophan); Preservation of non-meal biological resistance (capable of reduced blood cholesterol).

2.5. Influence on the human body Stimulation of normal microflora Normalization PH medium, neutralization of toxins Modelation of physiological functions, biochemical and behavioral reactions Participation in enzymatic and hormonal reactions Suppression of harmful microgants and stimulation of immunity production of vitamins Biofilm reduction

3. Translude we studied the role of microorganisms in the creation of fermented milk products, considered the effect of lactic acid bacteria on the gastrointestinal tract. Today, the treatment of most patients is unthinkable without the use of therapeutic nutrition. For this purpose, special diets have been developed. They are well known to doctors and are widely used. And, nevertheless, despite the big progress, the problem of nutrition remains and today is complex and not fully solved. That is why we have been engaged in the problem of clarifying the use of products containing lactic acid bacteria; The percentage ratio of the consumption of fermented milk products was found out and on the basis of the material studied suggested several recommendations on the compulsory consumption of dairy products. Nutrition is the necessary human vital need. Nutrition science relies on the achievements of physiology, biochemistry and, especially microbiology

4. References 1. Abramova-Obolenskaya N.I., Prokhorova I.I. et al. Correctional activity of acidophilic lactobacilli in the intestinal dysbiosis in the working dairy industry and the production of antibiotics. // in the book. Antibiotics and colonization resistance. M., 1990, V.Kh? X. p.160-166. 2. Androsova N.L., Nikonova N.K., Barysenkova E.P. Development of new types of fermented milk products for baby food. // Mat. 1st Vseros. Congress "Nutrition of children XX? century. M., 2000, p.143. 3. Goncharova G.I. Biofidoflora of man and the need for its optimization. - In the CN. Bifidobacteria and their use in the clinic, medical industry and agriculture. (Ed. Nikitin). M., 1986. Since 10-17. 4. Zimin V.S. et al. The technology for the preparation of fermented acidic food products based on complex breaks from lacto and bifidobacteria. M., 1986. 5. Korshunov V.M. The problem of regulation of intestinal microflora // J. Microbiol. 1995. №3 p. 48-53. 6. Lyannaya A.M., Intizarov M.M., Donskoye E.E. Biological and environmental features of the genus Bifidobacterium.- in the book: bifidobacteria and their use in the clinic, medical industry and agriculture (ed. Nikitin). M., 1986. P.32-38. 7. Manvelova M.A., Plyasunova N.G., Czech V.V. Therapeutic and dietary dairy food. - In the book: medical aspects of microbial ecology (ed. B.A. Seredov). M., 1992. T.6. P. 17-20. 8. Timakova G.A. Equal milk products in the structure of baby food // Mat. Issue. Conference "Probiotics and probiotic products in the prevention and treatment of the most common human diseases". M., 21-23 April 1999. P. 52-53. 9. Nutrition of breast and early children. Digest of articles. M., LLC "New Inform". 2002. 10. GOST 9225-84. Milk and dairy products. Methods of microbiological analysis.

Project work passport.

The name of the project " Bacteria in our lives »

Project Manager - I.A.Sttreker, teacher of biology and chemistry MBOU SOSH No. 24 PGT. Kaz.

An educational subject of biology, within the framework of which work is carried out.

Educational disciplines Close to the topic of the project: history, informatics.

Age 13 years old

Project Type: Research

purpose

An experienced way to confirm the significance of the conditions of our life for the growth and development of bacteria.

Tasks

1. To include the effect of bacteria on dairy products;

2. To examine the methods of combating pathogenic bacteria;

3. Jump hygienic rules.

I, Zhuravleva Maria, decided to explore the effect of bacteria on milk and potatoes and make a presentation on the topic "bacteria in our life." I decided to make this presentation and protect at the school environmental conference.

My work plan:

The choice of theme.

Search for information

Study

Presentation

5. Project protection.

What is microbes?! Where did they come from and what do they look?! We hear on TV and on the radio, we read in newspapers and on the Internet that bacteria and microbes are harmful organisms and they live in the environment around us - air, soil, water - from where they fall on items, clothes, in hand, in food , in the mouth, intestines.

The dimensions of the microbes are so small that they are measured by thousands and even by millions of millimeters. Microbes can only be considered using an optical or electron microscope. They can cause various diseases, poisoning. Therefore, it is necessary to observe sanitary and hygienic requirements.

Microbes a huge amount, and which live in us?! How do they differ and exist at all?!

In total, scientists counted 500 species of bacteria in samples.

Hypothesis: I want to make sure the existence of bacteria on our hands. And do you really need to wash your hands to protect yourself from bacteria?

Relevance: Are there bacteria on our hands?

Problem: Ways to protect against bacteria.

History of discoveries

See the microbial has become possible after the invention of the microscope. The first who saw and described microorganisms was the Dutch Naturalist Anthony Van Levenguk (1632-1723), which constructed a microscope that gave an increase of up to 300 times. In the microscope, he considered everything that came down at hand: water from a pond, various infusions, blood, dental flare and much more. In the objects viewed, he found the smallest creatures, called "live animals". He installed spherical, chopped and convoy forms of microbes. The opening of Lewenaguka marked the origin of microbiology.

French Chemist Scientist Louis Pasteur (1822-1895) First, who began to study bacteria and their properties. He proved that the microbes are the cause of fermentation and rotting, are able to cause diseases.

Merit in the development of microbiology I. I. Mechnikov (1845-1916). He also revealed human disease caused by bacteria. He organized the first bacteriological station in Russia. With the name of Mechnikov, the development of a new direction in microbiology - immunology - the teachings on the irrevocability of the body to infectious diseases (immunity).

Habitat

Bacteria - the very first living beings appearing on our planet.
Bacteria live almost everywhere where there is water, including hot springs, the bottom of the world's ocean, as well as deep inside the earth's crust. They are an important link in the exchange of substances in ecosystems.

There is practically no place on earth, wherever the bacteria would meet. They live in the ice of Antarctica at a temperature of -83 Celsius and in hot springs (volcano or in the desert), where the temperature reaches +85 or + 90 per Celsius. Especially many of them in the soil. In 1 gram, soil may contain hundreds of millions of bacteria.
The number of bacteria is different in the air of the ventricted and non-relieved premises. So, in the class after conducting before the start of the lesson, bacteria is 13 times less than before conducting

1.3. What are the bacteria. Bacteria are also useful and harmful.

Many animal bacteria are simply necessary for life. For example, food of ungulates, rodents, as you know, are plants. The bulk of any plant is fiber (cellulose). But it turns out to digest the fiber of beasts help bacteria living in the special sections of the stomach and intestines.

We know that putrid bacteria spoil food products. But this harm that they bring to man is nothing compared to the benefit that they bring nature in general. These bacteria can be called "natural agencies". Separating proteins and amino acids, they maintain the cycle of substances in nature.

Prostokvash, cheese, sour cream, oil, kefir, sauerkraut, marinated vegetables - all these products would not exist, do not be lactic acid bacteria. Man uses them from ancient times. By the way, the Prostokvasha is absorbed threefold faster than milk - the body completely digested 90% of this product. Without lactic acid bacteria, there would be no silos going on cattle.

Building bacteria

The structure depends on the way of living and feeding the microorganism. Bacteria may have chopped (bacillos), spherical (cocci) and spiral (spirillas, vibrium, spirochetes) form.

How do they infect us ? Infectious (infectious) diseases were known in antiquity. The most severe of them (plague, cholera, smallpox) often took mass propagation, caused the cooking Mor, as a result of which the flowering cities turned into extensive cemeteries.

In addition to these particularly dangerous infections, there are still very many other infectious diseases that can cause epidemics - it is a dysentery, abdominal typhoids and parathy, rapid and returnful types, brucellosis, these diseases occur through dirty products and hands. The method of infection is the transfer of the pathogen into the respiratory tract through the air around us. The pathogens of many infectious diseases are highlighted by a sick organism from the amazed respiratory tract (nose, throat, bronchi, light). When a sick person says, coughs, sneezes, he throws the smallest splashes into the ambient air - droplets of infected sputum or nasal mucus. In this way, the microbes-pathogens are easily penetrated with the infected air into the nose, the throat, in the lungs healthy peoplewhere and happens further development Diseases. Such a "air" or "drip" way of movement of contagious microbes is observed when improving healthy people with influenza, scarletina, measles, diphtheria, cough, slippers, pork.

Survey observation.

Insided 20 people as they wash hands before meals, 19 people know that before eating you need to wash your hands with soap it - 98% of students. After the work done, I was interested in the question: "How often do the hands behed in front of the student food?". During the change, I began to observe at the entrance to the dining room, did the students wash?

Result:

When surveyed students, "do they know that before meal you need to wash your hands?", 98% of students answered that they know, and understand why it is necessary.

Jumping on schoolchildren at the entrance to the dining room, I found out that my hands werehed before eating without soap about 8 people, and 12 people were not soaked hands.

Conclusion: I know little, you need to also apply knowledge to keep your health.

My experiences.

I washed, cleaned the potato tuber, cut into 2 stakes, dulled in soda solution, welded, cooled. It became sterile 2 glass jars with covers, put №1 a bank share of potatoes with dirty hands, No. 2 to the bank of potatoes was flushed with soap. Banks put in a warm place. As a result, after 4 days, potatoes, which took dirty hands was covered with the colonies of bacteria tightly, and in the bank number 2 potatoes were partially covered with colonies.

Conclusion: There are a lot of bacteria on dirty hands.

Experience number 2 (with milk)

Getting sophisticated milk.

I took a fresh milk 1 cup, put in a warm place the next day I received my prokozhvash

Getting sour cream from cream.

I took the cream 1stan put in a warm place, in the day it turned out sour cream

Conclusion: Thus, I was convinced that useful bacteria help to make many tasty products.