Project work passport.

Project name " Bacteria in our life"

The project manager is I.A. Shtreker, teacher of biology and chemistry of Municipal Budgetary Educational Institution Secondary School No. 24 of the village. Kaz.

The academic subject is biology, within which the work is carried out.

Academic disciplines close to the topic of the project: history, computer science.

Age 13

Project type: Research

Target

To experimentally confirm the importance of our living conditions for the growth and development of bacteria.

Tasks

1.Study the effect of bacteria on dairy products;

2.Study methods of combating pathogenic bacteria;

3.Study hygiene rules.

I, Maria Zhuravleva, decided to investigate the effect of bacteria on milk and potatoes and make a presentation on the topic “Bacteria in our lives.” I decided to make this presentation and defend it at a school environmental conference.

My work plan:

Selecting a topic.

Search for information

Study

Making a Presentation

5. Project protection.

What are microbes?! Where did they come from and what do they look like?! We hear on TV and radio, read in newspapers and on the Internet that bacteria and microbes are pests and they live in the environment around us - air, soil, water - from where they then end up on objects, clothes, hands, food, mouth, intestines.

The sizes of microbes are so small that they are measured in thousandths and even millionths of a millimeter. Microbes can only be seen using an optical or electron microscope. They can cause various diseases and poisoning. Therefore, it is necessary to comply with sanitary and hygienic requirements.

There are a huge number of microbes, but which ones live in us?! How do they differ and do they exist at all?!

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

Hypothesis: I want to make sure that there are bacteria on our hands. And is it really necessary to wash your hands to protect yourself from bacteria?

Relevance: Do bacteria exist on our hands?

Problem: ways to protect against bacteria.

History of discoveries

It became possible to see a microbe after the invention of the microscope. The first to see and describe microorganisms was the Dutch naturalist Antony van Leeuwenhoek (1632-1723), who designed a microscope that provided magnification up to 300 times. Through a microscope, he examined everything that came to hand: pond water, various infusions, blood, dental plaque and much more. In the objects he examined, he discovered the smallest creatures, which he called “living animals.” He established spherical, rod-shaped and convoluted forms of microbes. Leeuwenhoek's discovery marked the beginning of the emergence of microbiology.

French chemist Louis Pasteur (1822-1895) was the first to study bacteria and their properties. He proved that microbes cause fermentation and decay and can cause disease.

I. I. Mechnikov (1845-1916) deserves great credit for the development of microbiology. It also identified human diseases caused by bacteria. He organized the first bacteriological station in Russia. The name of Mechnikov is associated with the development of a new direction in microbiology - immunology - the study of the body's immunity to infectious diseases (immunity).

Habitat

Bacteria are the very first living creatures to appear on our planet.
Bacteria live almost everywhere there is water, including hot springs, the bottom of the world's oceans, and also deep inside earth's crust. They are an important link in metabolism in ecosystems.

There is practically no place on Earth where bacteria are found. They live in the ice of Antarctica at a temperature of -83 Celsius and in hot springs (volcano or desert), where the temperature reaches +85 or +90 Celsius. There are especially many of them in the soil. 1 gram of soil can contain hundreds of millions of bacteria.
The number of bacteria is different in the air of ventilated and unventilated rooms. So, in the classroom after ventilation before the start of the lesson there are 13 times less bacteria than before ventilation

1.3. What types of bacteria are there? Bacteria can be both beneficial and harmful.

For many animals, bacteria are simply necessary for life. For example, plants are known to serve as food for ungulates and rodents. The bulk of any plant is fiber (cellulose). But it turns out that bacteria living in special parts of the stomach and intestines help animals digest fiber.

We know that putrefactive bacteria spoil food. But the harm they bring to humans is nothing compared to the benefits they bring to nature as a whole. These bacteria can be called “natural orderlies.” By decomposing proteins and amino acids, they support the cycle of substances in nature.

Curdled milk, cheese, sour cream, butter, kefir, sauerkraut, pickled vegetables - all these products would not exist if it were not for lactic acid bacteria. Man has been using them since ancient times. By the way, yogurt is digestible threefold faster than milk- within an hour the body completely digests 90% of this product. Without lactic acid bacteria there would be no silage for livestock feed.

Structure of bacteria

The structure depends on the way of life and food supply of the microorganism. Bacteria can have rod-shaped (bacilli), spherical (cocci) and spiral-shaped (spirilla, vibrio, spirochetes) shapes.

How they infect us? Contagious (infectious) diseases have been known since ancient times. The most severe of them (plague, cholera, smallpox) often spread massively and caused widespread pestilence, as a result of which flourishing cities turned into vast cemeteries.

In addition to these particularly dangerous infections, there are many other known infectious diseases that can cause epidemics - dysentery, typhoid and paratyphoid fever, typhus and relapsing fever, brucellosis, these diseases occur through dirty food and hands. The method of infection is the transfer of the pathogen into the respiratory tract through the air around us. The causative agents of many infectious diseases are secreted by the sick body from the affected respiratory tract (nose, pharynx, bronchi, lungs). When a sick person speaks, coughs, or sneezes, he throws tiny sprays into the surrounding air - droplets of infected sputum or nasal mucus. In this way, pathogenic microbes easily penetrate along with contaminated air into the nose, pharynx, and lungs of healthy people, where it occurs further development diseases. This “air” or “droplet” path of movement of infectious microbes is observed when healthy people are infected with influenza, scarlet fever, measles, diphtheria, whooping cough, smallpox, and mumps.

Survey-observation.

I interviewed 20 people about how they wash their hands before eating, 19 people know that they need to wash their hands with soap before eating - this is 98% of students. After the work done, I was interested in the question: “How often do students wash their hands before eating?” During the break, I began to observe at the entrance to the dining room, did the students wash their hands?

Result:

When surveying students, “Do they know that it is necessary to wash their hands before eating?”, 98% of students answered that they know and understand why this is necessary.

Having observed the schoolchildren at the entrance to the dining room, I found out that about 8 people washed their hands without soap before eating, and 12 people did not wash their hands.

Conclusion: it is not enough to know, you also need to apply knowledge to maintain your health.

My experiences.

I washed, peeled the potato tuber, cut it into 2 parts, soaked it in a soda solution, boiled it, cooled it. I made 2 glass jars with lids sterile, put a share of potatoes in the No. 1 jar with dirty hands, and a share of potatoes in the No. 2 jar with hands washed with soap. Placed the jars in a warm place. As a result, after 4 days, the potatoes that were taken with dirty hands were densely covered with colonies of bacteria, and in jar No. 2 the potatoes were partially covered with colonies.

Conclusion: dirty hands have a lot of bacteria.

Experiment No. 2 (with milk)

Making curdled milk from milk.

I took 1 glass of fresh milk, put it in a warm place, the next day I got yogurt

Making sour cream from cream.

I took 1 cup of cream and put it in a warm place, a day later it turned out to be sour cream

Conclusion: Thus, I was convinced that beneficial bacteria help make many delicious foods.

Problem: I decided to find out if bacteria are dangerous for humans?

Hypothesis: Bacteria can cause not only harm, but also benefit.

Object of study sour milk products and dirty hands.

Subject of study bacteria

Goal of the work: study the life characteristics of bacteria and find out whether they can be useful.

Research objectives:

1. Familiarize yourself with the characteristics of bacteria.

2. Find out where bacteria live.

3. Study literature data on the dangers or benefits of bacteria.

Research methods:

Download:

Preview:

MBOU "Kozul Secondary School No. 2"

Are bacteria my enemies or friends?

Research

Performed:

Yurkova Lada

student of 6th grade "B"

Supervisor:

Kukartseva Svetlana Vladimirovna,

biology teacher

Kozulka village, 2015

Introduction ……………………………………………………………………………..3

I. Analysis of literary sources...…………………………………………….4

I.1 a brief description of bacteria........................ ……………………………6

I.2. The human body and bacteria.........................8

I.3.Behavior of bacteria under various conditions.........…………………………..8

I.4. Amazing abilities of bacteria?.................................................... ................ 8

Conclusions on Chapter I.................................................. ...................................................

II. Experimental part ……………………………………………………..8

II.1 Effect of bacteria on lactic acid products....................................................

II.2 The benefits of following hygiene rules.................................................... ........

II.3 Questionnaire............................................................. ...................................................

Conclusions on Chapter II................................................... ........................................................ .

Conclusion ………………………………………………………………………...

Literature………………………………………………………………................................... .....

Applications ………………………………………………………………………..

INTRODUCTION

Relevance of the topic:

"Moidodyr" K.I. Chukovsky is one of my favorite children's books. And I always wondered why the crocodile, Moidodyr, washcloths, and soap were angry at the dirty one. This boy was just funny. My mother very often tells me that I need to wash my hands with soap after going outside, and be sure to wash fruits and vegetables before eating. She warned that some microbes would enter my body and I might get sick. It was interesting to me. Why might I get sick? What kind of microbes are these? How can they harm me? Where do they come from? Do all microbes harm humans? Who are these microbes and where are they if I don’t see them at all? Maybe mom was making it all up? But it turns out that we are surrounded by a whole world of invisible creatures that arose on the planet many billions of years ago, survived all the changes that took place on Earth: volcanic eruptions, glacial period, the death of many prehistoric animals. These creatures are called bacteria. They can be both beneficial and harmful to humans and animals. In order to understand what we are dealing with, I decided to find out more about them.

When we started talking about bacteria in biology class, I became interested and decided to get to know each other in more detail. mysterious world microorganisms. Now I have learned a lot about them and am ready to tell you.

Problem : I decided to find out if bacteria are dangerous for humans?

Hypothesis: Bacteria can cause not only harm, but also benefit.

Object of studysour milk products and dirty hands.

Subject of study bacteria

Goal of the work: study the life characteristics of bacteria and find out whether they can be useful.

Research objectives:

1. Familiarize yourself with the characteristics of bacteria.

2. Find out where bacteria live.

3. Study literature data on the dangers or benefits of bacteria.

Research methods:

Search – collection of information and literature on a given topic;

Research – information processing;

Practical – performing the experience;

Questionnaire

I Analysis of literary sources

I.1 BRIEF CHARACTERISTICS OF BACTERIA.

Our magical planet Earth is full of secrets and mysteries. Blue, green, yellow, red, white - all these are habitats. Every point on Earth contains a huge number of mysteries. And one of the mysteries is the creatures living on it. They are varied: this huge trees baobabs are giant animal whales, huge elephants. And we are people, creatures endowed with the great gift of reason. We think. With the help of reason, man makes discoveries and tries to uncover the secrets of nature.

For thousands of years man was sick and did not know the cause of the disease. Primitive people They had their own explanation for this - they believed that the disease was caused by evil spirits. It was only at the beginning of the 19th century that man invented the microscope. This is a device that helped man discover another mystery of nature - the world of the smallest organisms - bacteria. In 1865 Louis Pasteur proved that germs are the cause of disease. They are tiny single-celled microorganisms visible only under a microscope. Before a person could see bacteria, he had to deal with the results of their activity. For example, when milk sours, dough rises, wine ferments, and dead plants and animals decompose. Thus, when people talk about bacteria, many people immediately think of harmful organisms that carry disease. But the fact is that there are many different types of bacteria that are beneficial to living organisms, including humans.

Today we know that bacteria are everywhere - in the air, water, food, day sea ​​ocean, hot springs, deep inside the earth's crust, on our skin and even inside us.

The science of MICROBIOLOGY studies microorganisms. The name of the science comes from the Greek word “MIKROS” - small. Modern microbiology is divided into: general, technical, agricultural, sanitary, medical, radiation, space.

The most generally accepted theories about the origin of life on Earth say that microorganisms were the first living organisms to appear through the process of evolution.¹

Microorganisms are divided into several groups: BACTERIA, YEAST, MOLD FUNGI, VIRUSES.

BACTERIA – single-celled organisms belonging to prokaryotes. About 3000 species of bacteria are known. Their sizes are microscopic, from 1 to 10 microns, width from 0.2 to 1 microns. Most bacteria are one cell, but physiologically they are an integral organism, completely biochemically structured.

Bacteria have three shapes: spherical, rod-shaped and curved or convoluted. Most microbes breathe air - they are aerobes. For others, the air is harmful - these are anaerobes. Microbes are divided into pathogenic (disease-causing) and non-pathogenic. The causative agents of most infectious diseases are bacteria. In the environment around us: air, soil, water - there are many microorganisms, from where they get onto objects, clothes, hands, food, mouth, intestines.

Like all living things, microorganisms feed and reproduce. Microbes do not have special digestive organs. Nutrients enter microorganisms through the cell membrane. Therefore, for the development of microbes, products containing a lot of water are a good nutrient medium - milk, broths, meat, fish, etc. Bacteria do not have male or female individuals. Bacteria reproduce by division. In addition to the nutrient medium, a favorable temperature (37-40 degrees) is required. Once in favorable conditions, microbes begin to rapidly multiply by fission.

At temperatures above 50 degrees, most bacteria die. The bacterium consists of one cell, it is surrounded by a coating - a “membrane” that does not allow water to pass through. Inside the bacterium there is a substance called "protoplasm", but there is no single center, or nucleus.

Bacteria are able to move, although they do not have limbs. The bacterium is covered with a mucous membrane, which changes its shape, sometimes forming fibrous processes. Some bacteria move with their help, others - by cutting the cell itself, like worms.

I. 2. HUMAN BODY AND BACTERIA.

Microorganisms play a vital role in the circulation of substances and maintaining balance in the Earth's biosphere. Bacteria cause rotting of dead plants and animals on land and in water. Without these bacteria, the earth would be covered in various dead materials. Recycling complex substances, bacteria decompose them into simple ones. These substances are returned to the soil, air and water, where they can be used by plants and animals.

Bacteria are essential to sustain life. For example, nitrogen-containing bacteria live in the soil and help convert this nitrogen into substances that plants need. And humans eat these plants.

Bacteria play an important role in the human digestive process. These bacteria break down food into particles. At the same time, they produce vitamins, proteins, and carbohydrates, which the body uses to build itself.

Thanks to the activity of microbes, cabbage is fermented, dough, kefir, cheese, and butter are prepared. Bacteria are necessary in the fermentation process in the production of cottage cheese, vinegar, wine, and beer. The same process is used in the industrial production of paints, plastics, cosmetics and confectionery. Bacteria are needed in production for the production of leather, removal of shells from coffee and cocoa beans, and separation of fibers in the textile industry.

So, there are many varieties of microbes, and they live in entire colonies. Naturally, living in the human body, they must protect their owner and not harm him.

What is the intestine of a healthy person, that is, the population of this organ? In the intestines, 99% of microbes are selfless helpers of humans. They are called permanent microflora. Among them there are the main, main microorganisms - bifidobacteria and bacteroides. But there are also accompanying bacteria - these are Escherichia coli, lactobacilli, enterococci. Under certain conditions, representatives of normal microflora, except bifidobacteria, have the ability to cause diseases. However, there are more dangerous microbes in the intestines, no more than 1%. These are staphylococci and fungi. But while they are in the minority, they work for the benefit of the body. They are called opportunistic microbes. Why are we talking mostly about the intestines? The digestive tract is not homogeneous in composition and number of microorganisms. The esophagus has no permanent microflora at all and practically replicates the microflora of the oral cavity. Staphylococcus, pneumo- and streptococci constantly live on the mucous membrane of the nasopharynx. Plaque on teeth and food debris between them are a good environment for the life of microorganisms. The abundant development of microbes in the mouth leads to the rapid proliferation of food debris, while the chemical products of this decay accumulate, which destroy tooth enamel and lead to the development of caries. Therefore, it is so important to systematically brush your teeth and rinse your mouth after every meal.

The microbial spectrum of the stomach is poor and is represented by lactobacilli, streptococci, heliobacteria and acid-resistant yeast-like fungi. The microflora of the small intestine is not numerous and in the duodenum is represented by streptococci, lactobacilli and veillonella; in other sections the number of microbes is higher, and even more bacteria are found in the ileum, which, in addition to the listed microorganisms, contains E. coli. But the largest number of microbes lives in the large intestine. It is estimated that humans excrete over 17 trillion microbes per day in their stool, and by weight they account for a third of dry stool. If you take only intestinal bacteria, and collect them in one pile and weigh them, you will get about 3 kilograms!

I.3. BEHAVIOR OF BACTERIA IN DIFFERENT CONDITIONS

IS THERE LIFE IN BOILING WATER?

Until recently, it was believed that boiling water kills all bacteria, even the most persistent ones, but nature, as always, has refuted this belief. At the bottom Pacific Ocean super-hot springs with water temperatures ranging from 250 to 400 degrees C were discovered, and it turned out that living organisms thrive in this boiling water: bacteria, giant worms, various mollusks and even some types of crabs. This discovery seemed incredible. After all, most plants and animals die at body temperatures above 40 degrees; and most bacteria die at 70 degrees. Only a few bacteria are able to survive at 85 degrees C, and the most resistant bacteria were considered to be those living in sulfur springs. They can exist at t – 105C. But this was already the limit.

IS THERE LIFE IN ICE?

There are bacteria that live in ice. Freezing may stop the growth of bacteria, but will not kill them completely. They will be inactive for some time. Bacteria have been discovered in frozen salt deposits that are hundreds of millions of years old. These bacteria came to life when examined.

BACTERIA IN SPACE

“Scientists have long suspected that something evil was going on on starships and space stations; astronauts were getting sick too often. 15 of the 29 astronauts fell victim to bacterial or viral infections during their flight. Scientists' suspicions intensified even more when it turned out that on the Mir space stations and the ISS, seemingly harmless bacteria happily began to chew all kinds of structural materials, which led to accelerated corrosion.

All this prompted biologists to seriously study the behavior of microorganisms in space. In 2006 on the Atlantis shuttle in a securely insulated container in space trip a group of salmonella went. The bacteria stayed in space for only 24 hours, but this time was more than enough for them. Upon returning to Earth, it turned out that their infectiousness, compared to the control group, increased threefold. For a whole year, astrobiologists tried to understand what caused the increase in the aggressiveness of salmonella. In space, Salmonella activated a section of DNA that controls the functioning of 160 genes. In addition, salmonella began to unite, forming a thin layer - a biofilm, which makes any microorganisms extremely dangerous. Interestingly, such behavior was not typical for salmonella on Earth before. Some experts consider weightlessness to be the cause of the mutation, others - cosmic radiation.”

Over many years of work space station"Mir" has become a real testing ground for many technical solutions. It was on Mir that we managed to study small space free riders and learn how to fight them.

The microbes that inhabit space objects behave as if they have a specific purpose. It is simple: using all available nutrients, perform one of the main natural functions - to be fruitful and multiply. When microbes come into contact with a variety of materials, they quickly become established.

and start eating. As a result, the materials favored by the voracious invisibles change color and their strength, sealing properties, dielectric and other characteristics decrease.

Over the course of twenty years of research, scientists have discovered 250 species of microorganisms that live inside manned aircraft. spaceships. All samples of microorganisms grown in space are stored at the Institute of Medical and Biological Problems in sealed ampoules - scientists do not know how they will behave in the terrestrial environment. There is another reason for keeping space mutants in a secure location. According to experts, if you take a microorganism grown in space that used metal as part of its environment, and continue to cultivate it, increasing the metal content in its environment, you can potentially obtain a biological weapon that can literally devour a tank or a helicopter.

“The situation related to the navigation window of the Soyuz spacecraft, which spent six months in orbit, is especially interesting. Crew members noted a deterioration in the visibility of the window. After the ship returned to Earth, research was carried out. The presence of mold mycelium was noted on the central porthole made of heavy-duty quartz glass, as well as on the enamel coating of the titanium frame. In one case, a growing colony of the fungus was clearly visible. The glass was, as it were, etched along the growth lines of the mycelium.”

I.4. AMAZING ABILITIES OF BACTERIA

Currently, scientists are looking for alternative fuels, replacing oil, gas, and coal with safer ones - biological, more environmentally friendly. Created by scientists at the University of Texas the new kind microbes that produce cellulose, which in turn can be converted into ethanol and other biofuels. With the help of salt water, blue-green algae, along with cellulose, also produce glucose and sucrose, which is used to produce biofuel.

However, bacteria can participate in technological progress. After all, their ability to destroy almost any material can be used for the benefit of humans. Microorganisms may well be used in waste processing. Work is already underway to create bacteria that could decompose plastic. The fact is that plastic has no analogues in nature, so its decomposition process is very long. It is assumed that with the help of microorganisms, plastic can be broken down into water and methane, which can be used in heating and the chemical industry. Thus, in the near future, malicious bacteria may turn into the most useful guardians of the environment.

Houseplants can improve people's health. In a flower zone where there are many plants, special earth microbes have a special ability to neutralize volatile organic components that weaken human health. In the air of industrial cities, along with dust, there are millions of microorganisms. A liter of air in a poorly ventilated living room contains about 500 thousand dust particles. During the day, a person inhales about 10 thousand liters of air containing dangerous and non-dangerous microbes.

The cleaner the air in public places, around human habitation and in rooms, the less people sick. It is estimated that if you run a vacuum cleaner brush over the surface of an object four times, 50% of germs are removed. By maintaining hygiene, brushing your teeth, washing your hands with soap and food, and food, the likelihood of getting sick is reduced many times over.

Forests and parks are of great importance in the fight for clean air. Green spaces deposit and absorb dust and release phytoncides that kill microbes.

CONCLUSIONS ON CHAPTER I..........................................................

II. experimental part

II.1. Effect of bacteria on dairy products

Raw milk was poured into 2 jars, and boiled milk was poured into the third jar. Covered

lids one jar with raw milk and one with boiled milk. Observation

carried out over 3 days. The results were as follows.

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

II.2.The benefits of following hygiene rules.

Two days before the experiment, we covered the Petri dishes with lids. We prepared a nutrient mixture: the washed potato tuber was peeled, cut in half and soaked for 2-3 hours in a 1% soda solution, then boiled and cut into slices. Then we put the potato pieces on filter paper in Petri dishes (this is a nutrient medium for growing bacteria). They touched one plate with the finger of an unwashed hand, and the other with the finger of a washed hand, having first washed their hands well with soap. Two days later the results were compared.

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

During the first experiments and analysis of the literature, we found out that many traditional drinks and products, such as kefir, yogurt, kumiss, sour cream, cottage cheese, cheese, would not exist without the activity of special lactic acid bacteria. These bacteria, once in milk, begin to ferment and convert milk sugar into lactic acid. It not only adds flavor to drinks, but also prevents them from being contaminated by other microbes. Lactic acid bacteria are not only found in milk. Many of them live on the leaves of bushes and trees, feeding on substances that are released when plant tissues die. These bacteria are found in various food products, prepared by fermentation, for example in sauerkraut, pickled cucumbers, pickled olives. Lactic acid bacteria are used in agriculture to preserve feed. Juicy tops of beets or other fodder plants are placed in special pits and compressed. This process is called ensiling. After ensiling, many lactic acid bacteria develop in the compressed mass, and lactic acid reliably protects the silage from decomposition, and the feed only becomes better, since the bacteria enrich it with various beneficial substances.

The second experience showed us that................................... ..........

II.3.Questionnaire

Target: analyze students' knowledge about bacteria

To do this, we conducted a survey of school students in grades 7-8, in which 66 people participated. We found out that 60 people knew about the existence of bacteria, 6 people had never heard of them.

The majority of respondents (34 people) imagine bacteria as small, dirty and creepy - 5 people, the remaining 14 people have no idea. (Application 2 ).

To the question “Where can bacteria live?” They answered “everywhere” - 8 people, “on the body and in the body” - 10 people, “on the street and in different rooms” - 11 people, “nowhere” - 2 people.

According to the results of the survey “Can bacteria be beneficial?”: “yes” - 37 people, “no” - 29 people.

Basically, all the students surveyed at our school (66 people) know about the rules of hygiene and the need to wash vegetables and fruits before eating.

But when answering the question “Do you always practice good hygiene?” 48 children gave a positive answer, 16 people do this often, and the remaining 2 people occasionally observe the rules of hygiene. (Appendix 4)

Conclusion: 91% of respondents know about the existence of bacteria, but 44% of respondents believe that bacteria are not beneficial. 100% know the rules of hygiene, but 73% of children always follow them.

CONCLUSION

So, the topic I have discussed allows us to say that bacteria have great importance for a person. Humans and bacteria are inseparable. Microbes can be both enemies and friends. In the air of industrial cities, along with dust, there are millions of microorganisms. During the day we inhale a huge number of dangerous and non-dangerous microbes. Bacteria play a huge role in the purification processes of water contaminated with industrial and household waste. Many bacteria cause harm to humans, animals and plants, being the causative agents of various diseases. In order for bacteria to be our friends and not enemies, we need to: wash our hands with soap, wash our faces, brush our teeth, wash vegetables and fruits, plant a lot of trees. Take care of our planet, keep clean and breathe fresh air.

State Budgetary Educational Institution RO "Taganrog Sanatorium Boarding School"

Educational project on the topic:

Bacteria that cause infectious diseases in humans.

Style: creative

10th grade student

Cherkasov Pavel

Scientific supervisor: Yatsenko A.V.

Purpose of the project work

• 1. Identify the characteristics of bacteria as living beings.

2. Get to know the bacteria that cause infectious diseases in humans.

• 1. Study the habitat and structure of bacteria, nutrition and reproduction.
• 2. Determine the positive and negative roles of bacteria for human life.
• 3. Familiarize yourself with infectious diseases and methods of their prevention.
• 4. Create a design product.

• the results of work on the project can be used in biology, microbiology lessons, and in volunteer work. the results of work on the project can be used in biology, microbiology lessons, and in volunteer work.

• 1. The characteristics of a bacterial cell determine its properties as a causative agent of infectious diseases.
• 2. Knowledge about infectious diseases will reduce the level of infection of the population.

• Most bacteria reproduce by dividing the cell into 2 parts. Some reproduce by budding. The sexual process is noted only in a few cases (in E. coli). Bacteria are characterized by a high rate of reproduction: division occurs quickly (after 20-30 minutes). But their reproduction is limited climatic conditions, the action of sunlight, struggle between species, accumulation of metabolic products, etc.

• The expansion of the range of pathogens of human bacterial infections, the diversity of their properties and unequal medical significance require an increase in knowledge about the bacteria involved in the development of infectious processes. This knowledge is necessary for the formation of scientifically based medical tactics

BACTERIA

Project "Bacteria"

Project Manager: biology teacher T.A. Kobotova

Project participants: 7th grade students

Basagin Alexander – 7b

Bunevkina Daria – 7a

Ovchinnikov Artem – 7b

Gurchenok Denis – 7b

Afanasyeva Irina – 7a

Kharkin Dmitry – 7b

Andreev Vladimir – 7a

Project type: informational, creative, practice-oriented

Target: expand knowledge about bacteria

Tasks:

find, analyze and summarize information about bacteria;

learn about the science of bacteria;

consider the characteristics of these organisms;

identify the importance of bacteria in nature and in human life.

Problematic question: Are all bacteria harmful to humans?

Project presentation

In biology lessons, we learned that our hands contain a huge number of bacteria that are invisible to the naked eye. Most of these bacteria can cause serious human diseases, such as dysentery, salmonellosis, viral hepatitis, helminthic diseases and others.

But, studying the labels on the packages of various products (kefir, yogurt, sour cream), we discovered that they contained bacteria.

Then we wondered whether all bacteria are harmful to humans.

When we started working on the project, we assumed that bacteria could be both harmful to humans and beneficial.

Bacteria (ancient Greek - stick) - the kingdom of microorganisms, most often unicellular. Currently, about ten thousand species of bacteria have been described and it is estimated that there are over a million of them.

The branch of microbiology - bacteriology - studies bacteria.

Bacteria are the oldest group of organisms currently existing on Earth. The first bacteria probably appeared more than 3.5 billion years ago and for almost a billion years they were the only living creatures on our planet. Since these were the first representatives of living nature, their body had a primitive structure.

Over time, their structure became more complex, but to this day bacteria are considered the most primitive single-celled organisms. It is interesting that some bacteria still retain the primitive features of their ancient ancestors. This is observed in bacteria living in hot sulfur springs and anoxic mud at the bottom of reservoirs.

Most bacteria are colorless. Only a few are purple or green. But the colonies of many bacteria have a bright color, which is caused by the release of a colored substance into environment or cell pigmentation.

The discoverer of the world of bacteria was Antony Leeuwenhoek, a Dutch naturalist of the 17th century, who first created a perfect magnifying microscope that magnifies objects 160-270 times.

The name “bacteria” was coined by Christian Ehrenberg in 1828. Louis Pasteur in the 1850s initiated the study of the physiology and metabolism of bacteria, and also discovered their pathogenic properties.

Bacteria are classified as prokaryotes and are classified into a separate kingdom - Bacteria.

Body Shape

Bacteria are numerous and diverse organisms. They vary in shape.

Name of the bacterium

Bacteria image

Bacteria shape

Cocci

Ball-shaped

Bacillus

Rod-shaped

Vibrio

Comma-shaped

Spirillum

Spiral

Streptococci

Chain of cocci

Staphylococcus

Clusters of cocci

Diplococcus

Two round bacteria enclosed in one mucous capsule

Sizes of bacteria

The average size of bacteria is 0.5-5 microns. Bacteria are much smaller than the cells of multicellular plants and animals. Their thickness is usually 0.5–2.0 µm, and their length is 1.0–8.0 µm. Some forms are barely visible at the resolution of standard light microscopes (approximately 0.3 microns), but species are also known with a length of more than 10 microns and a width that also goes beyond the specified limits, and a number of very thin bacteria can exceed 50 microns in length. On the surface corresponding to the point marked with a pencil, a quarter of a million medium-sized bacteria will fit.

Methods of transportation

Among bacteria there are mobile and immobile forms. Motiles move due to wave-like contractions or with the help of flagella (twisted helical threads), which consist of a special protein called flagellin. There may be one or more flagella. In some bacteria they are located at one end of the cell, in others - at two or over the entire surface.

But movement is also inherent in many other bacteria that lack flagella. Thus, bacteria covered on the outside with mucus are capable of gliding movement.

Some aquatic and soil bacteria lacking flagella have gas vacuoles in the cytoplasm. There may be 40-60 vacuoles in a cell. Each of them is filled with gas (presumably nitrogen). By regulating the amount of gas in the vacuoles, aquatic bacteria can sink into the water column or rise to its surface, and soil bacteria can move in the soil capillaries.

Habitat

Microorganisms are ubiquitous. The only exceptions are craters active volcanoes and small sites at the epicenters of the explosions atomic bombs. Neither low temperatures Antarctica, neither boiling streams of geysers, nor saturated solutions salts in salt pools, nor harsh irradiation from nuclear reactors do not interfere with the existence and development of microflora. All living beings constantly interact with microorganisms, often being not only their repositories, but also their distributors. Microorganisms are natives of our planet, actively exploring the most incredible natural substrates.

Due to their simplicity of organization and unpretentiousness, bacteria are widespread in nature. Bacteria are found everywhere: in a drop of even the purest spring water, in grains of soil, in the air, on rocks, in polar snow, desert sands, on the ocean floor, in oil extracted from great depths, and even in the water of hot springs with a temperature of about 80ºC. They live on plants, fruits, various animals and in humans in the intestines, oral cavity, limbs, and on the surface of the body.

Bacteria are the smallest and most numerous living creatures. Due to their small size, they easily penetrate into any cracks, crevices, or pores. Very hardy and adapted to different conditions existence. They tolerate drying, extreme cold, and heating up to 90ºC without losing their viability.

Number of bacteriain the soil extremely large - hundreds of millions and billions of individuals in 1 gram. There are much more of them in soil than in water and air. The total number of bacteria in soils changes. The number of bacteria depends on the type of soil, their condition, and the depth of the layers.

The soil microflora is very diverse. Various physiological groups of bacteria are found here: rotting bacteria, nitrifying bacteria, nitrogen-fixing bacteria, sulfur bacteria, etc.

The area of ​​development of microorganisms in the soil is the zone adjacent to the roots of living plants. It is called the rhizosphere, and the totality of microorganisms contained in it is called the rhizosphere microflora.

Water – natural environment, where in large quantities microorganisms develop. The bulk of them enters the water from the soil. A factor that determines the number of bacteria in water and the presence of nutrients in it. The cleanest waters are from artesian wells and springs. Open reservoirs and rivers are very rich in bacteria. Largest quantity bacteria are found in the surface layers of water, closer to the shore. As you move away from the shore and increase in depth, the number of bacteria decreases.

Clean water contains 100-200 bacteria per 1 ml, and polluted water contains 100-300 thousand or more. There are many bacteria in the bottom sludge, especially in the surface layer, where the bacteria form a film. This film contains a lot of sulfur and iron bacteria, which oxidize hydrogen sulfide to sulfuric acid and thereby prevent fish from dying.

In terms of species composition, the microflora of water is similar to the microflora of soil, but there are also specific forms. By destroying various waste that gets into the water, microorganisms gradually carry out the so-called biological purification of water.

Microfloraair and is less numerous than the microflora of soil and water.

Bacteria rise into the air with dust, can remain there for some time, and then settle on the surface of the earth and die from lack of nutrition or under the influence of ultraviolet rays. The number of microorganisms in the air depends on the geographical zone, terrain, time of year, dust pollution, etc. each speck of dust is a carrier of microorganisms. Most bacteria are in the air above industrial enterprises. The air in rural areas is cleaner. Most fresh air over forests, mountains, snowy areas. The upper layers of air contain fewer microbes. The air microflora contains many spore-bearing bacteria, which are more resistant than others to ultraviolet rays.

BodyHuman and, even completely healthy, is always a carrier of microflora. When the human body comes into contact with air and soil, various microorganisms, including pathogenic ones (tetanus bacilli, gas gangrene, etc.), settle on clothing and skin. The most frequently exposed parts of the human body are contaminated. E. coli and staphylococci are found on the hands. There are over 100 types of microbes in the oral cavity. The mouth, with its temperature, humidity, and nutrient residues, is an excellent environment for the development of microorganisms.

The stomach has an acidic reaction, so the majority of microorganisms in it die. Starting from the small intestine, the reaction becomes alkaline, i.e. favorable for microbes. The microflora in the large intestines is very diverse. Each adult excretes about 18 billion bacteria daily in excrement, i.e. more individuals than people on the globe.

Internal organs that are not connected to the external environment (brain, heart, liver, bladder, etc.) are usually free of microbes. Microbes enter these organs only during illness.

External structure

The bacterial cell is covered with a special dense shell - a cell wall, which performs protective and supporting functions, and also gives the bacterium a permanent, characteristic shape. The cell wall of a bacterium resembles the wall of a plant cell. It is permeable: through it, nutrients freely pass into the cell, and metabolic products exit into the environment. Often, bacteria produce an additional protective layer of mucus on top of the cell wall - a capsule. The thickness of the capsule can be many times greater than the diameter of the cell itself, but it can also be very small. The capsule is an optional part of the cell; it is formed depending on the conditions in which the bacteria find themselves. It protects the bacteria from drying out.

On the surface of some bacteria there are long flagella (one, two or many) or short thin villi. The length of the flagella can be many times greater than the size of the body of the bacterium. Bacteria move with the help of flagella and villi.

Internal structure

Inside the bacterial cell there is dense, immobile cytoplasm. It has a layered structure, there are no vacuoles, therefore various proteins (enzymes) and reserve nutrients are located in the substance of the cytoplasm itself. Bacterial cells do not have a nucleus. In the central part of their cell, a substance carrying hereditary information bacteria, - nucleic acid - DNA. But this substance is not formed into a nucleus.

The internal organization of a bacterial cell is complex and has its own specific characteristics. The cytoplasm is separated from the cell wall by the cytoplasmic membrane. In the cytoplasm, there is a main substance, or matrix, ribosomes and a small number of membrane structures that perform the most various functions(analogues of mitochondria, endoplasmic reticulum, Golgi apparatus). The cytoplasm of bacterial cells often contains granules of various shapes and sizes. The granules may be composed of compounds that serve as a source of energy and carbon. Droplets of fat are also found in the bacterial cell.

Eating methods

Bacteria have different feeding methods. Among them there are autotrophs and heterotrophs.

Autotrophs are organisms that can independently form organic substances for their nutrition.

Saprophytic bacteria

Bacteria-symbionts

Extract nutrients from dead and decaying organic material. They usually secrete their digestive enzymes into this decaying material, and then absorb and assimilate the dissolved products

(lactic acid bacteria, putrefaction bacteria, etc.)

They live together with other organisms and often bring tangible benefits to them. Bacteria living in the thickenings of the roots of legume plants.

They live inside or on another organism, shelter and feed on its tissues, causing various diseases - bacteriosis

(meningococci, gonococci, etc.)

Plants need nitrogen, but cannot absorb nitrogen from the air themselves. Some bacteria combine nitrogen molecules in the air with other molecules, resulting in substances that are available to plants.

These bacteria settle in the cells of young roots, which leads to the formation of thickenings on the roots, called nodules. Such nodules form on the roots of plants of the legume family and some other plants.

The roots provide the bacteria with carbohydrates, and the bacteria provide the roots with nitrogen-containing substances that can be absorbed by the plant. Their cohabitation is mutually beneficial.

Plant roots secrete a lot organic matter(sugars, amino acids and others) that bacteria feed on. Therefore, especially many bacteria settle in the soil layer surrounding the roots. These bacteria convert dead plant debris into plant-available substances.

Plant cells filled with rapidly multiplying cells of nodule bacteria begin to rapidly divide. The connection of a young nodule with the root of a legume plant is carried out thanks to vascular-fibrous bundles. During the period of functioning, the nodules are usually dense. By the time optimal activity occurs, the nodules acquire a pink color (thanks to the leghemoglobin pigment). Only those bacteria that contain leghemoglobin are capable of fixing nitrogen.

Nodule bacteria create tens and hundreds of kilograms of nitrogen fertilizer per hectare of soil.

Metabolism

Bacteria differ from each other in their metabolism. For some it occurs with the participation of oxygen, for others - without it.

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

Bacteria absorb substances from the outside, tear their molecules into pieces, assemble their shell from these parts and replenish their contents (this is how they grow), and throw unnecessary molecules out. The shell and membrane of the bacterium allows it to absorb only the necessary substances.

If the shell and membrane of a bacterium were completely impermeable, no substances would enter the cell. If they were permeable to all substances, the contents of the cell would mix with the medium - the solution in which the bacterium lives. To survive, bacteria need a shell that allows necessary substances to pass through, but not unnecessary substances.

Sporulation

Spores form inside the bacterial cell. During the process of sporulation, the bacterial cell undergoes a number of biochemical processes. The amount of free water in it decreases. This ensures the resistance of the spores to unfavorable environmental conditions (high temperature, high salt concentration, drying, etc.). Sporulation is characteristic of only a small group of bacteria.

Spores are an optional stage in the life cycle of bacteria. Sporulation begins only with a lack of nutrients or accumulation of metabolic products. Bacteria in the form of spores can remain dormant for a long time.

Bacterial spores can withstand prolonged boiling and very long freezing. When favorable conditions occur, the spore germinates and becomes viable.

Bacterial spores are an adaptation to survival in unfavorable conditions.

Reproduction

Bacteria reproduce by dividing one cell into two. Having reached a certain size, the bacterium divides into two identical bacteria. Then each of them begins to feed, grows, divides, and so on.

After cell elongation, a transverse septum gradually forms, and then the daughter cells separate; In many bacteria, under certain conditions, after dividing, cells remain connected in characteristic groups. In this case, depending on the direction of the division plane and the number of divisions, different shapes. Reproduction by budding occurs as an exception in bacteria.

Under favorable conditions, cell division in many bacteria occurs every 20-30 minutes. With such rapid reproduction, the offspring of one bacterium in 5 days is capable of forming 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 per day. If converted into weight - 4720 tons. However, this does not happen in nature, since most bacteria quickly die under the influence of sunlight, drying, lack of food, heating to 65-100ºC, as a result of struggle between species, etc.

The role of bacteria in nature

Bacteria are the most important link in the general cycle of substances in nature. Plants create complex organic substances from carbon dioxide, water and mineral salts in the soil. These substances return to the soil with dead fungi, plants and animal corpses. Bacteria break down complex substances into simple ones, which are then used by plants.

Bacteria destroy complex organic substances of dead plants and animal corpses, excretions of living organisms and various wastes. Feeding on these organic substances, saprophytic bacteria of decay turn them into humus. These are a kind of orderlies of our planet. Thus,bacteria actively participate in the cycle of substances in nature .

Since bacteria are distributed almost everywhere and are found in a huge number, they largely determine various processes occurring in nature. In autumn, the leaves of trees and shrubs fall, above-ground shoots of grasses die, old branches fall off, and from time to time the trunks of old trees fall. All this gradually turns into humus. 1 cm 3 The surface layer of forest soil contains hundreds of millions of saprophytic soil bacteria of several species. Thesebacteria convert humus into various minerals , which can be absorbed from the soil by plant roots.

Some soilbacteria are able to absorb nitrogen from the air using it in life processes. These nitrogen-fixing bacteria live independently or settle in the roots of legume plants. Having penetrated the roots of legumes, these bacteria cause the growth of root cells and the formation of nodules on them.

These bacteria produce nitrogen compounds that plants use. Bacteria obtain carbohydrates and mineral salts from plants. Thus, there is a close relationship between the legume plant and the nodule bacteria, which is beneficial to both one and the other organism. This phenomenon is called symbiosis.

Thanks to symbiosis with nodule bacteria, leguminous plants enrich the soil with nitrogen, helping to increase yield.

The human body contains several trillion cells and more than 100 trillion bacteria of five hundred species. The total weight of bacteria living in the human body is 2 kilograms.

There are about 40,000 bacteria in the human mouth. Fortunately, 95 percent of them are harmless.

Lactobacilli and bifidobacteria live in the human body. They appear in our body from the first years of infancy and remain in it forever, complementing each other and solving serious problems. Lactobacilli and bifidobacteria enter into complex reactions with other microorganisms, easily suppress putrefactive and pathogenic microbes. As a result, lactic acid and hydrogen peroxide are formed - these are natural internal antibiotics. Thus,lactobacilli raise, restore the body's defenses and strengthen the immune system .

The beneficial functions of lactobacilli were first noticed by the Russian scientist Ilya Ilyich Mechnikov. The idea of ​​using fermented milk products to normalize biochemical processes in the intestines and nourish the body as a whole belongs to him.

But there are others -pathogenic, or pathogenic , bacteria. They are able to penetrate the tissues of plants, animals and humans and release substances that inhibit the body’s defenses. A number of other human diseases of bacterial origin are known (bacterial pneumonia, tuberculosis, whooping cough, typhoid fever, dysentery, cholera, etc.).methods of struggle with bacteria are: drying fruits, mushrooms, meat, fish, grain; their cooling and freezing in refrigerators and glaciers; marinating foods in acetic acid; pickling. When pickling cucumbers, tomatoes, mushrooms, or sauerkraut, the activity of lactic acid bacteria creates an acidic environment that inhibits the development of bacteria. This is what food preservation is based on. To destroy bacteria and preserve products, a method is usedpasteurization - heating to 65°C for 10-20 minutes and sterilization method- boiling. High temperature causes the death of all bacterial cells. In addition, in medicine, the food industry, and agriculture, iodine, hydrogen peroxide, boric acid, potassium permanganate, alcohol, formalin and other inorganic and organic substances are used for disinfection, i.e., to destroy pathogenic bacteria.

The role of bacteria in the biosphere is great. Thanks to their vital activity, the decomposition and mineralization of organic substances of dead plants and animals occurs. The resulting simple inorganic compounds(ammonia, hydrogen sulfide, carbon dioxide etc.) are involved in the general cycle of substances, without which life on Earth would be impossible. Bacteria along with fungi and lichensdestroy rocks , thereby participating in the initial stages of soil-forming processes.

Bacteria play a positive role in economic activity person . Lactic acid bacteria are used in the preparation of a variety of dairy products (sour cream, curdled milk, butter, cheese, etc.). They also help preserve food. Bacteria are widely used in modern biotechnology for industrial production lactic, butyric, acetic and propionic acids, acetone, butyl alcohol, etc. During their life processes, they are formed biologically active substances- antibiotics, vitamins, amino acids. Finally, bacteria are an object of research in the fields of genetics, biochemistry, biophysics, space biology, etc.

Conclusion

While working on the project, we learned that bacteria live everywhere. Theyplaypositive role in human economic activity. Lactic acid bacteria are used in the preparation of a variety of dairy products (sour cream, curdled milk, butter, cheese, etc.). They also help preserve food. Bacteria are widely used in modern biotechnology for the industrial production of lactic, butyric and acetic acids, acetone, and butyl alcohol. In the process of their vital activity, biologically active substances are formed - antibiotics, vitamins, amino acids.

Negative role belongspathogenic, orpathogenic,

bacteria.They are able to penetrate the tissues of plants, animals and humans and release substances that inhibit the body’s defenses. A number of other human diseases of bacterial origin are known (bacterial pneumonia, tuberculosis, whooping cough, typhoid fever, dysentery, brucellosis, cholera)

That's whyassumptionThe fact that bacteria can be both harmful and beneficial to humans has been fully confirmed.

Author of the project

Ivanayskaya Zoya Ivanovna

Project name

Educational theme of the project "Bacteria"

Creative theme"Invisible Animals"

Subject, class

Biology, 6th grade

Brief summary of the project

The project is carried out with 6th grade students. Subject areas are Hygiene, Biology, Ecology. The project is aimed at developing in students knowledge about the structural features of bacteria, their role in nature and human life. During the project, schoolchildren will become familiar with the characteristic features of bacteria, learn to distinguish them from other organisms. This project helps to increase the level cognitive activity students, develops observational skills, creativity, instills interest in studying biology

Project plan

Questions guiding the project

Fundamental Question: If the "Cute Animals" disappear, what will happen to the Earth?

1. Problematic question: Why did bacteria appear on earth?
   1. Study question: Conditions necessary for life to exist on Earth?
   2. Study question: When did bacteria appear?
   3. Study question: Is life possible on Earth in an oxygen-free environment?
2. Problematic question: Do bacteria have the same structure?
   1. Study question: How can we view a bacterium?
   2. Study question: What forms of bacteria are there?
   3. Study question: What organelles does a bacterial cell have?
3. Problematic question: What are the differences between bacteria and other living things?
   1. Study question: Conditions necessary for bacteria to live?
   2. Study question: Do bacteria reproduce, and how?
   3. Study question: What types of bacteria exist in nature?

Teacher publication

Teacher presentation to identify student ideas and interests

An example of a student project activity product

Formative and summative assessment materials

Before the start of the project, we use an assessment strategy to determine the needs of students to study the project topic "Bacteria", as this strategy is used to determine basic level students. This strategy helps to assess the level of knowledge of students. During the project we use the strategy of developing independence and interaction. This strategy is used to assess the ability of students to take responsibility for their own learning, interpersonal skills, creating high quality work, understanding feedback and assessing the work of peers. After completion, strategies are used to prove understanding and skills. This strategy evaluates the knowledge and skills that schoolchildren have mastered while working on the project. In addition, this strategy will help identify problems in the students’ knowledge. And at the end of the project, each group will present their product: 1-booklet, 2- self-observation diary, 3-table.

Assessment strategy

Formative assessment