summary of other presentations

“Concepts of the origin of life” - Problem. Primary genetic material. The main difficulty of the hypothesis. Problems in modern science. Biochemical evolution. Degree of order. Panspermia theory. Archbishop Usher. RNA world. Interaction. There are many theories about the origin of life. French scientist. Italian biologist. Basic postulates of the theory of biochemical evolution. The idea of ​​spontaneous generation. Founder of the theory of panspermia.

“The problem of the origin and essence of life” - Natural history approach. Oparin. Steady state concept. DNA molecules. The body of a person weighing 70 kg contains 45.5 kg of oxygen. Property of chirality. Creationism. Viruses. Messenger RNA. Anaxagoras. Panspermia concept. The idea of ​​spontaneous generation. Basic provisions. Symposiums on the problem of the origin of life. Biopolymers. The main merit of Oparin. The concept of biochemical evolution.

“How life arose on Earth” - The concept of biogenesis. Changes in the Earth's atmosphere. L. Pasteur. Van Helmont. Steady state theory. Spontaneous origin of life. The emergence of life on Earth. A.I. theory Oparina. F.Redi. Vitalism. L. Spallanzani. Panspermia. Life in the Earth. Natural origin of life. Experience of S. Miller. Theories of the origin of life. Microorganisms. Atmosphere of the Earth. Creationism. Theory of biochemical evolution.

“Concepts of the origin of life on Earth” - Radiation panspermia. Cell. Evolution theory. Emergence scheme. Soviet biochemist. Reverse directed panspermia. Germs of life. Experiments on the reproduction of amino acids. Chemist Stanley Miller. Plant cell. Panspermia theory. Creationism. What is life. Vernadsky. Paracelsus. Chemical elements. Living content of the cell. Polypeptides. The theory of spontaneous generation. Formaldehyde. A modern view of the origin of life.

“Theories of the emergence of life” - Organic compounds. Coacervate. Stages of life formation according to Oparin. Organisms are different from non-living things. Biopoiesis hypothesis. Biogenic method. Van Helmont. Oparin's theory of biochemical evolution. The hypothesis of the spontaneous origin of life on Earth. Steady State Hypothesis. French microbiologist Louis Pasteur. Hypothesis of biochemical evolution. Panspermia hypothesis. What is life. Properties of protein.

“The oldest organisms on Earth” - The oldest organisms. Phylum Brachiopod. List of temporary units. What period are we living in? Similarities. Similarities and differences. Equipment. Modern representatives. Jan Baptist Van Helmont. The theory is evolutionary. Representatives of the class of bivalve mollusks. The birth of life. Comb castle. Class Trilobites. Class Bivalves. Geochronological table. Theory of divine origin.

“Earth Development” - Exhausted, supporting each other, burning our feet on the hot sand, we walked for five days through low thickets of thorny eucalyptus bushes. HALL No. 2 1. Based on the proposed paintings, determine the name and show these natural zones on the map. 2. Sounds that we recognize. What does the name mean? HALL No. 1 Practical work: 1. Study the proposed exhibits. 2. Determine: a) Which samples are fossil remains of organisms (fossils) b) Which samples are reconstructible. 3. Formulate a conclusion: Why is it necessary to study fossil remains of organisms? 4. From the given letters, form the name of the science that studies ancient fossils.

“The emergence and development of life” - Heraclitus. The possibility of repeated life on Earth is excluded. Life arose on Earth abiogenically. The world consists of five elements: earth, water, air, fire, and ether. The basis of everything is fire... Aristotle. The beginnings of the Universe are atoms and emptiness. The emergence and initial development of life on Earth.

“Development of the organic world” - Today we are experiencing one of the periods of warming. The supercontinent Gondwana stretches across the equator. PALEOCENE ERA (Tertiary period). Flora As the climate cooled, steppes replaced forests. Duration: FROM 570 TO 500 MILLION. CENIOZOIC ERA (era of new life). Duration: FROM 65 TO 55 MILLION.

“Theory of Life” - Scientific. Let's remember monotheism. Monotheism is one of the directions of creationism. Let's look at the example of Christianity. BUT still, in the religion of Ancient Egypt there are many gods. Spontaneous origin of life: For Democritus, the beginning of life was in mud, for Thales - in water, for Anaxagoras - in the air. Ancient Egypt.

"Education of Life" - Paleozoic. Star formation. Archaea. Proterozoic.

“Development of life on Earth” - The project is designed for two weeks. Project on the topic Stages of development of life on Earth. Creative title “Equanimity in everything, complete harmony in nature” F.I. Tyutchev. Developmental: promote the development of information culture and the formation of interest in research work. Subject: biology. © Municipal Educational Institution Lyubimskaya Secondary School, 2010

There are 20 presentations in total

Test on the topic:
"The Origin of Life on Earth"

Option 1

Part A

1.

b) the presence of catalysts;

d) metabolic processes.

2.

a) anaerobic heterotrophs;
b) aerobic heterotrophs;
c) autotrophs;
d) symbiont organisms.

3. Such a general property of living things as self-regulation includes:

a) heredity;
b) variability;
c) irritability;
d) ontogeny.

4. The essence of the theory of abiogenesis is:

c) the creation of the world by God;

5. A crystal is not a living system because:

a) he is not capable of growth;

c) he is not characterized by irritability;

6. Louis Pasteur's experiments proved the possibility of:

a) spontaneous generation of life;


d) biochemical evolution.

7.

a) radioactivity;
b) the presence of liquid water;
c) the presence of gaseous oxygen;
d) mass of the planet.

8. Carbon is the basis of life on Earth, because... He:

9. Eliminate unnecessary things:

a) 1668;
b) F. Redi;
c) meat;
d) bacteria.

10.

a) L. Pasteur;
b) A. Levenguk;
c) L. Spallanzani;
d) F. Redi.

Part B

Complete the sentences.

1. The theory postulating the creation of the world by God (the Creator) is….

2. Prenuclear organisms that do not have a nucleus limited by a shell and organelles capable of self-reproduction are ....

3. A phase-separated system interacting with the external environment like an open system is ....

4. The Soviet scientist who proposed the coacervate theory of the origin of life is ....

5. The process by which an organism acquires a new combination of genes is….

Part B

Give brief answers to the following questions.

1. What are the common characteristics of living and nonliving matter?

2. Why should there be no oxygen in the Earth's atmosphere when the first living organisms arose?

3. What was Stanley Miller's experience? What corresponded to the “primary ocean” in this experience?

4. What is the main problem of the transition from chemical to biological evolution?

5. List the main provisions of the theory of A.I. Oparina.

Option 2

Part A

Write down the numbers of the questions, next to them write down the letters of the correct answers.

1. Living things differ from non-living things:

a) the composition of inorganic compounds;

c) interaction of molecules with each other;
d) metabolic processes.

2. The first living organisms on our planet were:

a) anaerobic heterotrophs;
b) aerobic heterotrophs;
c) autotrophs;
d) symbiont organisms.

3.

a) metabolism;
b) reproduction;
c) irritability;
d) ontogeny.

4. The essence of the theory of biogenesis is:

a) the origin of living things from non-living things;
b) the origin of living things from living things;
c) the creation of the world by God;
d) the introduction of life from Space.

5. A star is not a living system because:

a) she is not capable of growth;

c) she is not irritable;

6.

a) spontaneous generation of life;
b) the emergence of living things only from living things;
c) bringing in “seeds of life” from Space;
d) biochemical evolution.

7. Of these conditions, the most important for the emergence of life is:

a) radioactivity;
b) availability of water;
c) availability of an energy source;
d) mass of the planet.

8. Water is the basis of life because:

a) is a good solvent;


d) has all of the listed properties.

9. Eliminate unnecessary things:

a) 1924;
b) L. Pasteur;
c) meat broth;
d) bacteria.

10. Place the following names in logical order:

a) L. Pasteur;
b) S. Miller;
c) J. Haldane;
d) A.I. Oparin.

Part B

Complete the sentences.

1. The process of formation by living organisms of organic molecules from inorganic ones due to the energy of sunlight - ....

2. Precellular formations that had some properties of cells (the ability to metabolize, self-reproduce, etc.) - ....

3. Separation of a protein solution containing other organic substances into phases with a higher or lower concentration of molecules - ....

4. An English physicist who suggested that adsorption was one of the stages of concentration of organic substances during prebiological evolution - ....

5. A system characteristic of all living organisms for recording hereditary information in DNA molecules in the form of a sequence of nucleotides - ....

Part B

1. What was Stanley Miller's experience? What corresponded to the “lightning” in this experience?

2. Why should the mass of a planet on which life can arise not be more than 1/20 the mass of the Sun?

3. To what stage of the development of life on Earth can the words of Gogol’s hero be attributed: “I don’t remember the date. It wasn't a month either. What the hell was that?

4. What conditions are necessary for life to arise?

5. What is panspermia? Which of the scientists you know adhered to this theory?

Option 3

Part A

Write down the numbers of the questions, next to them write down the letters of the correct answers.

1. Living things differ from non-living things:

a) the composition of inorganic compounds;
b) the ability to reproduce itself;
c) interaction of molecules with each other;
d) metabolic processes.

2. The first living organisms on our planet were:

a) anaerobic heterotrophs;
b) aerobic heterotrophs;
c) autotrophs;
d) symbiont organisms.

3. Such a general property of living things as self-renewal includes:

a) metabolism;
b) reproduction;
c) irritability;
d) ontogeny.

4. The essence of creationism is:

a) the origin of living things from non-living things;
b) the origin of living things from living things;
c) the creation of the world by God;
d) the introduction of life from Space.

5. A river is not a living system because:

a) she is not capable of growth;
b) she is not capable of reproduction;
c) she is not capable of irritability;
d) not all properties of living things are inherent in it.

6. Francesco Redi's experiment proved the impossibility:

a) spontaneous generation of life;
b) the emergence of living things only from living things;
c) introducing “seeds of life” from space;
d) biochemical evolution.

7. Of these conditions, the most important for the emergence of life is:

a) radioactivity;
b) availability of water;
c) an infinitely long evolutionary time;

8. During the period of the emergence of life, there should have been no oxygen in the Earth’s atmosphere, because:

a) it is an active oxidizing agent;
b) has a high heat capacity;
c) increases its volume when frozen;
d) all of the above in combination.

9. Eliminate unnecessary things:

a) 1953;
b) bacteria;
c) S. Miller;
d) abiogenic synthesis.

10. Place the following names in logical order:

a) L. Pasteur;
b) F. Redi;
c) L. Spallanzani;
d) A.I. Oparin.

Part B

Complete the sentences.

1. The formation of organic molecules from inorganic ones outside living organisms - ....

2. Liquid bubbles surrounded by protein films that arise when shaking aqueous solutions of proteins are ....

3. The ability to reproduce similar biological systems, which manifests itself at all levels of organization of living matter, is ....

4. The American scientist who proposed the thermal theory of the origin of protobiopolymers is ....

5. Protein molecules that accelerate the course of biochemical transformations in aqueous solutions at atmospheric pressure are ....

Part B

Give a short answer to the question posed.

1. What is the main difference between the burning of wood and the “burning” of glucose in cells?

2. What are three modern points of view on the problem of the origin of life?

3. Why is carbon the basis of life?

4. What was Stanley Miller's experience?

5. What are the main stages of chemical evolution?

Option 4

Part A

Write down the numbers of the questions, next to them write down the letters of the correct answers.

1. Living things differ from non-living things:

a) the composition of inorganic compounds;
b) the ability to self-regulate;
c) interaction of molecules with each other;
d) metabolic processes.

2. The first living organisms on our planet were:

a) anaerobic heterotrophs;
b) aerobic heterotrophs;
c) autotrophs;
d) symbiont organisms.

3. Such a general property of living things as self-reproduction includes:

a) metabolism;
b) reproduction;
c) irritability;
d) ontogeny.

4. The essence of the panspermia theory is:

a) the origin of living things from non-living things;
b) the origin of living things from living things;
c) the creation of the world by God;
d) bringing “seeds of life” to Earth from Space.

5. A glacier is not a living system because:

a) he is not capable of growth;
b) he is not capable of reproduction;
c) he is incapable of irritability;
d) not all properties of a living thing are inherent to it.

6. The experiment of L. Spallanzani proved the impossibility:

a) spontaneous generation of life;
b) the emergence of living things only from living things;
c) bringing in “seeds of life” from Space;
d) biochemical evolution.

7. Of these conditions, the most important for the emergence of life is:

a) radioactivity;
b) availability of water;
c) the presence of certain substances;
d) a certain mass of the planet.

8. Carbon is the basis of life because... He:

a) is the most common element on Earth;
b) the first of the chemical elements began to interact with water;
c) has a low atomic weight;
d) capable of forming stable compounds with double and triple bonds.

To be continued

FEDERAL EDUCATION AGENCY

State educational institution of higher education

Secondary technical faculty

Department of Mathematical and Natural Sciences

BIOLOGY

Lecture notes

for 1st year students

all forms of education

Kemerovo 2010

Compiled by:

Teacher,

Reviewed and approved at the meeting

Department of Mathematics and Natural Sciences

secondary technical faculty

The course of general biology examines the main aspects of the existence and functioning of living systems in relation to the environment. And also, the basics of selection of living organisms and genetic engineering. Much attention is paid to revealing the theory of evolution.

© Kem TIPP, 2010

PREFACE

Our time is characterized by the extremely increased interdependence of people. A person’s life, his health, his working and living conditions depend almost entirely on the correctness of decisions made by so many other people. In turn, the activities of an individual influence the fate of many others. That is why it is very important that life science becomes an integral part of the worldview of every person, regardless of his specialty. A builder, technologist, land reclamation specialist needs knowledge of biology in the same way as a doctor or agronomist, because only in this case will they understand the consequences of their production activities for nature and humans.

The purpose of this course of lectures is to give an idea of ​​the structure of living matter, its most general laws, to introduce the diversity of life and the history of its development on Earth. In accordance with this, special attention is paid to the analysis of the relationships between organisms and the conditions for the stability of ecosystems. The course provides examples characterizing human subordination to all known biological laws.

SECTION 1 ORIGIN AND INITIAL STAGES OF DEVELOPMENT OF LIFE ON EARTH

Topic 1.1 Diversity of the living world. Basic

properties of living things

Terminology

1. Inorganic compounds- elements and simple and complex substances formed by them, found in large quantities outside living organisms.

2. Organic compounds- compounds of carbon with other elements, found mainly in living organisms.

3. Biopolymers– high molecular weight organic compounds, the monomers of which are simple organic molecules.

4.Cell– a structural and functional unit, as well as a unit of development of all living organisms.

5. Textile– a collection of cells similar in structure, connected by performing common functions.

6. Organ- a set of spatially isolated tissues specialized to perform certain functions.

7. Biological system– biological objects of varying degrees of complexity, having several levels of organization. Has the properties of the whole.

Biology is the science of life. Biology studies the structure, manifestation of life activity, and habitat of all living organisms on the planet. Living things on the planet are represented by an extraordinary variety of forms, many types of living beings. Scientists constantly find and describe new species, both existing and extinct in past eras.

One of the main tasks of biology is to reveal the general properties of living organisms and explain the reasons for their diversity, identifying connections between structure and living conditions.

Of great importance in science are the questions of the origin and laws of development of life on Earth - the doctrine of evolution. Understanding these laws is the basis of the scientific worldview.

According to the subject of study, biology is divided into separate sciences:

Botany;

Zoology;

Anatomy;

Medicine;

Ecology, etc.

Each of these sciences has its own divisions and, thanks to the accumulated knowledge, is increasingly specialized.

In accordance with the level of organization of living matter, scientific disciplines are distinguished: molecular biology, cytology - the study of cells, histology - the study of tissues, etc.

Biology uses a variety of study methods:

1. historical;

2. descriptive;

3. instrumental.

In various areas of biology, the importance of borderline disciplines is increasingly growing: biophysics, biochemistry, bionics.

The emergence of life and the functioning of living organisms are determined by natural laws. Knowing them allows you to create an accurate picture of the world and use it for practical purposes.

Recent achievements in biology have led to the emergence of new directions in science, which have become independent sections in the complex. (Genetic Engineering). The practical application of the achievements of modern biology currently makes it possible to obtain new biological substances - food, medicines, materials. Nature's exceptional ability to self-heal has created the illusion of its invulnerability and the limitlessness of its resources. But that's not true. Therefore, all human activities must be based on the principles of organization of the biosphere.

The importance of biology for humans is enormous. General biological laws are used to solve a variety of issues in many sectors of the national economy. In agriculture, great success has been achieved in developing new varieties of cultivated plants, breeds of domestic animals, and strains of microorganisms. In the future, the practical importance of biology will increase even more. This is due to the rapid growth of the planet's population and the growing urban population. In such a situation, intensification of agricultural production is important. The scientifically based use of natural resources will play an important role in this.

The first living beings appeared on our planet 3 billion years ago. From these early forms arose countless species of living organisms that appeared, flourished for a period of time, and then died out. From previously existing forms, modern living organisms evolved, forming the four kingdoms of nature:

More than 1.5 million animal species;

350 thousand plant species;

A significant number of mushroom species;

Many organisms are prokaryotes.

The world of living beings, including humans, is represented by biological systems of various structural organizations. All living organisms are made up of cells. A cell can be a separate organism or part of a multicellular plant or animal. It can be simple or complex. Any cell is a whole organism capable of performing all functions to ensure life. The cells that make up a multicellular organism are specialized - they perform one function and are not able to exist outside the body. In higher organisms, the interconnection and interdependence of cells leads to the creation of a new quality that is not equal to a simple sum. Their combination in the process of evolution forms an integral organism with certain properties inherent only to it.

Levels of organization of living matter

Living nature is a complexly organized system.

There are several levels of organization of living things:

1. Molecular(0.1 – 1 mm.) 10m.

The most important life processes of the body begin from this level. Any system, no matter how complex it is, is carried out at the level of interaction of biological macromolecules - proteins, polysugars, DNA.

2. Cellular(10nm – 1µm) 1m.

Cell- the smallest structural unit of all living things. There are no non-cellular life forms. Viruses are an exception because they live only in a cell.

3. Fabric(10µm – 100µm) 1m.

Textile is a collection of cells similar in structure, united by a common function.

4.Organ(100µm – 1mm) 1m.

Organ is a structural and functional combination of several types of tissues.

5. Organismal(1mm – 1dm) 1m.

Organism is the simplest unicellular or multicellular system capable of independent existence. It is formed by a collection of tissues and organs.

6. Population-species.

A set of organisms of the same species, united by a common habitat, creates a population in which elementary evolutionary transformations take place.

7. Biogeocenotic.

Biogeocenosis is a collection of organisms of different species and varying complexity of organization with all environmental factors.

8. Biosphere.

This is the highest level of life organization. It includes living matter, inert matter and bio-inert matter.

The biomass of the planet is 2.5·1012 tons. Of this, 99% of the mass of land organisms is represented by green plants. At the biosphere level, there is a circulation of substances and the transformation of energy associated with the life activity of all living organisms on the planet.

Criteria for living systems

This is a system of assessments that distinguish living systems from inanimate objects.

1. Features of the chemical composition. Living organisms contain the same chemical elements as inanimate objects. However, their ratio is not the same. Elements of inanimate nature are represented by: O2, Si, Fe, Mg, Al, S, MeO, MeS, MeCO3, etc. In living organisms, 98% of the composition is O2, C, N2, H2. They are part of complex organic molecules: proteins, DNA, carbohydrates, fats.

2. Metabolism. All living organisms are capable of exchanging substances with their environment. The most important processes are synthesis and decay. Living organisms absorb various substances from the environment and process them. Part goes to building the body, part to replenishing energy costs. This is assimilation or plastic exchange. This is dissimilation or energy exchange, when organic compounds break down into simple ones and energy is released. Metabolism ensures homeostasis of the body - this is the constancy of its structure and functions.

3. A single principle of structural organization. All organisms at any level of complexity and size are composed of cells.

4. Reproduction. At the organismal level, reproduction manifests itself in the form of multiplication of individuals. The offspring are similar to the parents. Self-reproduction is based on the reaction of template synthesis during self-duplication of DNA.

5. Heredity. This is the ability of organisms to transmit their characteristics, properties, and abilities from generation to generation. Heredity ensures material continuity over a number of generations.

6. Growth and development. The ability to develop is a universal property of matter. Development is understood as an irreversible, directed change in natural objects. As a result, a new, qualitative state of the object arises, its composition and structure change.

A) individual – ontogenesis.

B) historical – phylogeny.

7. Irritability. This is the property of living organisms to selectively respond to external influences. Multicellular organisms respond to stimulation using a reflex. Organisms that do not have a nervous system react with tropisms - the direction of growth, movement (heliotropism - movement towards the sun).

8. Discreteness. This is a property of living matter. It goes from simple to complex. The discrete structure of an organism is the basis of its structural order.

9. Autoregulation. This is the ability of living organisms in a changing environment to maintain the constancy of the chemical composition and the intensity of physiological processes. This activity is regulated by the function of special systems.

10. Energy dependence. Living bodies are energetically open systems. Metabolic processes are carried out in them through membranes (membranes, skin). They maintain the consistency of composition and unity of the system. Living organisms exist with a constant supply of matter and energy from the outside.

Life– this is an active, with the expenditure of energy received from the outside, maintenance and self-reproduction of a specific structure.

Control questions

1. The essence of the term “Biology”.

2. Biology department by subject of study.

3. Division of biology by level of organization.

4. The importance of biology for humans.

5. Diversity of the living world.

6. Biological systems.

7. Levels of organization of living things.

8. Criteria for living systems.

Topic 1.2 The emergence of life on Earth

Terminology

1. Nebula- a large accumulation of gas and dust matter in the universe.

2. Galaxy– a star and its surrounding planets.

3. star system- a system of stars with surrounding planets, developing from one nebula.

4. Planet- a celestial body moving in a close to circular orbit around a star, glowing with reflected light.

5. Abiogenic synthesis– the formation of organic molecules from inorganic ones outside living organisms.

6. Energy– a general quantitative measure of the momentum of matter.

7. Solution– homogeneous mixtures of two or more substances distributed in a solvent.

8. Coacervation – separation of the BMC solution into phases with higher and lower concentrations of molecules.

9. Coacervate- liquid bubbles surrounded by protein films.

10. Adsorption– absorption of a substance from a liquid medium by the surface of a solid body.

The question of the origin of life on Earth, and also, probably, on other planets of other star systems has worried man since the time he began to recognize himself as a human being, began to understand himself and the world around him. The first attempts to theoretically solve the problem go back to ancient times and bear the imprints of those eras and views. There have been two points of view on this issue since ancient times: one affirms the possibility of the origin of living things from non-living things - this is the theory of abiogenesis, the other - the theory of biogenesis - denies the spontaneous origin of life. Modern views only allow us to put this dispute on a scientific basis and thereby substantiate the correctness of the theory of abiogenesis.

Representations of ancient and medieval philosophers

The general level of knowledge in the ancient world was low, and views were fantastic. Ignorance of the methods of reproduction of organisms was the reason why it was considered possible for the emergence of living beings from dead remains or inorganic substances. These views were supported by the church. The discovery of the microscope expanded the understanding of the structure of organisms; the theory of the origin of living things from non-living things was rejected. The experiments of the Italian Redi (mid-17th century) proved that all living things come from living things. However, the theory of spontaneous generation of living things from non-living things existed in the ears of scientists for a long time. The experiments of the Frenchman L. Pasteur finally dispelled this theory. Based on Pasteur's work, methods of sterilization and preservation were developed. This happened in 1870.

Subsequently, this question was transferred to the cell, and microorganisms were no longer considered. Simultaneously with Pasteur's work, the theory of the eternity of life arose. According to Richter's theory, in 1865 life was brought to Earth from other planets. This theory does not reveal the essence of the origin of life, it only tries to explain its appearance.

A special place in resolving the issue belongs to materialistic theories. The key issue here is the differences between living and nonliving things. Scientists take the formation of protein compounds as the basis for the origin of living things. According to the theory of the Englishman Ellen in 1899. The first appearance of nitrogenous compounds on Earth coincides with the period when water vapor condensed into water and covered the surface of the planet. The water was saturated with salts, which are of great importance for the formation and activity of protein. In this hot solution, in the presence of ultraviolet radiation, electrical discharges, and a large amount of carbon dioxide, the birth of living things began, which subsequently went through a long path of evolution.

While exploring the question of the origin of living things, one should simultaneously understand the processes that occur during the formation of the planet. Astronomy and chemistry provide the answer to these questions. The main method of space exploration is spectroscopy. Analyzing the light emitted by stars provides rich information about their chemical composition. From the end of the 19th century. 2 million were registered. spectra of 15 thousand stars and the Sun. Conclusion - the same chemical elements exist everywhere and the same physical laws apply. Formation of the planet.

The most common element is hydrogen (H-H, H-He). In a universe formed from hydrogen, stars are formed as the primary substance. The main nuclear reaction is the fusion of hydrogen nuclei to form a helium atom and release energy. This energy moves the universe. According to the law of conservation of mass, the energy released during formation is converted into radiation energy. Further interaction of elements leads to the formation of other chemical elements. These reactions are expressed in the formation of more complex molecules and their aggregates - dust particles. They form clusters of gas and dust matter in space. For example, a giant nebula in the constellation Orion. Its diameter is 15 light years, the amount of dust is enough to form 100 thousand stars the size of the Sun. The Milky Way nebula has a diameter of 100 thousand light years. The Orion Nebula is the closest to us, at a distance of 1500 light years. The Earth and other planets of the solar system were formed from a gas and dust cloud 4.5 billion years ago. Despite the common origin of the planets, life appeared only on Earth and reached exceptional diversity. For the emergence of life on Earth, cosmic and planetary conditions were necessary. Firstly, these are the optimal sizes of the planet. Secondly, movement in a circular orbit provides constant heat. Thirdly, the constant radiation of the star. All these conditions were satisfied by the Earth, on which, about 4.5 billion years ago, conditions were created for a higher level of development of matter and its evolution towards the emergence of life.

Modern ideas about the origin of life. All modern ideas about the origin of life on Earth are based on the recognition of abiogenic, i.e., non-biological origin of organic substances from inorganic molecules. This is the opinion of a Russian scientist (1924).

Chemical evolution

In the first stages, the Earth had a very high temperature. As it cooled, heavy elements moved to its center, while light elements remained on the surface. Metals were oxidized and there was no free oxygen in the atmosphere. It consisted of H2, CH4, NH3, HCN and was of a reducing nature. This served as a prerequisite for the emergence of organic substances by non-biological means. Until the beginning of the 20th century, it was believed that they could only occur in the body. In this regard, they were called organic, and the substances were called minerals, inorganic. In 1953 it was proven that by passing a current through a mixture of gases H2, CH4, NH3, HCN in the absence of oxygen, a mixture of amino acids was obtained. Subsequently, many organic compounds were obtained abiogenically. All of them were subsequently discovered in space.

More than 4 billion years ago, the entire globe was the “Miller's flask”. Volcanoes erupted, lava flowed, steam swirled, lightning flashed. As the planet cooled, water vapor condensed and rained down on the planet for millions of years. A primary ocean was formed, hot and saturated with salts; in addition, the resulting sugars, amino acids, and organic acids got there. As the climate moderated, the formation of more complex compounds became possible, resulting in the appearance of primary biopolymers - polynucleotides and polypeptides.

The primordial ocean contained various organic and inorganic molecules in soluble form. Their concentration constantly increased and gradually the waters became a “broth” of nutritious organic compounds. Each molecule has a specific structural organization: some are dissociated, some have hydration shells. Organic molecules have a large molecular weight and a complex structure. Molecules surrounded by an aqueous shell combine to form high-molecular complexes - coacervates. In the primordial ocean, coacervate droplets absorbed other substances or were destroyed or enlarged. As a result, the drops became more complex and adapted to external conditions. Among the coacervates, the selection of the most resistant forms began. Differences have emerged between the chemical composition of the internal and external environments. As a result of chemical evolution, those forms were preserved that did not lose their structural features when breaking down into daughter forms. This is the ability to reproduce itself. In the process of evolution, the connection of nucleic acids and protein molecules led to the emergence of the genetic code. This sequence of nucleotides served as information for the sequence of amino acids in the protein molecule. (Reproduction of one's own kind). Gradually, the lipid layers around the coacervates were transformed into an outer membrane. This predetermined the path of further evolution. The formation of primary cellular organisms marked the beginning of biological evolution.

The emergence of prokaryotes

The selection of coacervates continued for about 750 million years. As a result, nuclear-free prokaryotes appeared. According to the method of solution, they were heterotrophs - they used the organic matter of the primary ocean. In the absence of atmospheric oxygen, they had an anaerobic metabolism. It is ineffective. Gradually, food supplies in the ocean were depleted. Competition for food began.

Organisms capable of using solar energy for the synthesis of organic matter found themselves in a more advantageous position. This is how photosynthesis emerged. This led to the emergence of a new power source. Then photosynthetic organisms learned to use water as a source of hydrogen. Their absorption of carbon dioxide was accompanied by the release of oxygen and the incorporation of carbon into organic compounds. (Today, ocean surface prokaryotes produce up to 78% of renewable oxygen.)

The transition from the primary atmosphere to an oxygen environment is a very important event. An ozone screen is formed in the upper layers, and a more favorable oxygen type of metabolism appears. New forms of life began to emerge on Earth with greater use of the environment.

Emergence of eukaryotes

Eukaryotes arose as a result of the symbiosis of various prokaryotes. This is how the ancestors of the primitive living flagellated protozoa arose. Symbiosis of flagellates with photosynthetic algae or plants.

The capabilities of unicellular organisms in mastering their habitat were limited. 2.6 billion years ago multicellular organisms appeared. The basis of modern ideas about the origin is explained by the theory of phagocytella. Multicellular organisms evolved from colonial flagellates. They still exist today. These colonies turned into a simple but integral organism.

Thus, the emergence of life on Earth is associated with a long process of chemical evolution. The formation of the membrane-shell contributed to the beginning of biological evolution. Both the simplest and the most complex have a cell at the core of their structural organization.

Control questions

1. History of ideas about the origin of life.

2. Works by L. Pasteur.

3. The theory of the eternity of life.

4. Formation of inorganic substances and formation of the planet.

5. Theory.

6. Biological evolution.

7. The emergence of the first multicellular organisms.

Chapter2 Cytology - THE STUDY OF THE CELL

Topic 2.1 Chemical organization of the cell. Macro and microelements

Terminology

1. Bioelements– chemical elements that are the basis of organic molecules.

2.Macronutrients– chemical elements included in the composition of organic molecules in quantities exceeding 1%.

3. Microelements– chemical elements included in the composition of organic molecules in an amount not exceeding 0.001%.

4. Homeostasis– a state of dynamic equilibrium of a natural system, supported by the activities of regulatory systems.

5. Buffer solutions– a solution of organic or inorganic substances, the pH value of which does not change when small amounts of alkali or acid are added.

The simplest microorganisms are individual cells. The body of all multicellular organisms consists of a greater or lesser number of cells, which are blocks that form a living organism. Regardless of whether a cell is an integral system or part of it, it has a set of characteristics common to all cells.

Chemical organization of cells

Cells contain about 70 elements of the periodic table, which are also found in inanimate nature. This is one of the proofs of the commonality of living and inanimate nature. However, the ratio of elements, their contribution to the formation of the elements that make up the organism and non-living things, differ sharply.

Depending on the ratio of elements in the composition of the body, they are distinguished:

1. macroelements (98% of cell mass) H2, O2, C, N.

2. trace elements (1.5%) S, P, K, Na, Ca, Mg, Mn, Fe, Cl. Each of them performs very important functions in the cell.

3. other (0.5%) B, Zn, Cu, I2, F2CO, Se.

All these elements participate in the construction of the body either in the form of ions or as part of certain compounds - molecules of organic and inorganic compounds.

Inorganic substances in the cell

These include water and mineral salts.

Water– the most common inorganic compound in living organisms. Its amount ranges from 10% in tooth enamel to 90% in germ cells. It depends on age, time of day, time of year.

Water molecules are represented by dipoles: depending on the temperature, the molecules can be free or combined into groups with the presence of hydrogen bonds. The dipole nature determines the high chemical activity of water. Water plays the role of a medium in the cell; it brings and carries away nutrients. Water undergoes numerous hydrolysis reactions. Having good thermal conductivity, water regulates the temperature in the cell.

Mineral salts - this is most of the inorganic compounds. They are in the form of ions or undissociated molecules. K+, Na+, Ca+2 are of great importance. They provide a constant water content, solution environment. The buffering environment ensures the constancy of all internal processes in the cell.

Organic substances in a cell

They make up 20-30% of the cell mass. These include biopolymers - proteins, nucleic acids, carbohydrates, fats, ATP, etc.

Different types of cells contain different amounts of organic compounds. Complex carbohydrates predominate in plant cells, while proteins and fats predominate in animal cells. Nevertheless, each group of organic substances in any type of cell performs functions: providing energy, being a building material, carrying information, etc.

Squirrels. Among organic substances, cells and proteins occupy first place in quantity and importance. In animals they account for 50% of the dry mass of the cell.

The human body contains many types of protein molecules that differ from each other and from proteins in other organisms.

Peptide bond:

When combined, the molecules form: a dipeptide, tripeptide or polypeptide. This is a compound of 20 or more amino acids. The order of transformation of amino acids in a molecule is very diverse. This allows the existence of variants that differ in the requirements and properties of the protein molecules.

The sequence of amino acids in a molecule is called structure.

Primary – linear.

Secondary – spiral.

Tertiary - globules.

Quaternary - association of globules (hemoglobin).

The loss of structural organization by a molecule is called denaturation. It is caused by changes in temperature, pH, and radiation. With minor exposure, the molecule can restore its properties. It is used in medicine (antibiotics).

The functions of proteins in a cell are diverse. The most important is construction. Proteins are involved in the formation of all cell membranes in organelles. The catalytic function is extremely important - all enzymes are proteins. Motor function is provided by contractile proteins. Transport - consists of attaching chemical elements and transferring them to tissues. The protective function is provided by special proteins - antibodies formed in leukocytes. Proteins serve as a source of energy - with the complete breakdown of 1g of protein, 11.6 kJ is released.

Carbohydrates. These are compounds of carbon, hydrogen and oxygen. Represented by sugars. The cell contains up to 5%. The richest are plant cells - up to 90% of the mass (potatoes, rice). They are divided into simple and complex. Simple - monosaccharides (glucose) C6H12O6, grape sugar, fructose. Disaccharide – (sucrose) C]2H22O11 beet and cane sugar. Polysugars (cellulose, starch) (C6H10O5)n.

Carbohydrates perform mainly construction and energy functions. When 1g of carbohydrate is oxidized, 17.6 kJ is released. Starch and glycogen serve as the cell's energy reserves.

Lipids. These are fats and fat-like substances in the cell. They are esters of glycerol and high molecular weight saturated and unsaturated acids. They can be solid or liquid – oils. In plants they are contained in seeds, from 5-15% of dry matter.

The main function is energy - when 1g of fat is broken down, 38.9 kJ is released. Fats are nutrient reserves. Fats perform a construction function and are a good heat insulator.

Nucleic acids. These are complex organic compounds. Consist of C, H2, O2, N2, P. Contained in the nuclei and cytoplasm.

a) DNA is a biological polynucleotide consisting of two chains of nucleotides. Nucleotides - consist of 4 nitrogenous bases: 2 purines - Adenine and Valine, 2 pyrimedines Cytosine and Guanine, as well as sugar - deoxyribose and a phosphoric acid residue.

In each chain, nucleotides are connected by covalent bonds. Chains of nucleotides form helices. A DNA helix packed with proteins forms a structure - a chromosome.

b) RNA is a polymer whose monomers are nucleotides similar to DNA, nitrogenous bases - A, G, C. Instead of thymine there is Urace. The carbohydrate in RNA is ribose and there is a phosphoric acid residue.

Double-stranded RNAs are carriers of genetic information. Single-chain - carry information about the sequence of amino acids in a protein. There are several single-stranded RNAs:

Ribosomal – 3-5 thousand nucleotides;

Information – nucleotides;

Transport - 76-85 nucleotides.

Protein synthesis is carried out on ribosomes with the participation of all types of RNA.

Control questions

1. Is a cell an organism or a part of it?

2. Elementary composition of cells.

3. Water and minerals.

4. Organic substances of the cell.

6. Carbohydrates, fats.

Topic 2.2 Cell structure and functions

Terminology

1. Biological membrane– a bimolecular layer of phospholipids with various protein molecules immersed in it from different sides.

2. Organoids– strictly specialized structures constantly present in the cytoplasm.

3. Cytoskeleton– a system of microtubules and protein fibers that ensures the maintenance of cell shape and the spaciousness of structures in the cytoplasm.

4. Mitochondria– energy stations of the cell, on the membranes of which enzymes of energy metabolism are arranged in an orderly manner.

5. Plastids- organelles in which photosynthesis occurs.

6. Inclusions- structures that are not constantly present in the cytoplasm, which are products of cell vital activity and act as a supply of nutrients.

Biochemical transformations are inextricably linked with various structures of a living cell, which are responsible for performing a particular function. Such structures are called organelles because, like the organs of a whole organism, they perform a specific function. According to the level of organization (degree of complexity), all cells are divided into non-nuclear - prokaryotes and nuclear - eukaryotes. Nuclear-free include bacteria and blue-green algae. Eukaryotes include cells of fungi, animals and plants.

Thus, modern science distinguishes two levels of cellular organization: prokaryotic and eukaryotic. Prokaryotes retain features of extreme antiquity: they are very simply structured. On this basis, they are separated into an independent kingdom - crushers.

Eukaryotic cells contain a nucleus limited by a shell, as well as complex “energy stations” - mitochondria. In other words, all cells of nuclear organisms are highly organized, adapted to the consumption of oxygen and therefore can produce large amounts of energy.

The structure of prokaryotes

Bacteria are typical prokaryotes. They live everywhere: in water, soil, food. The list of living conditions shows what a high degree of adaptability prokaryotes have, despite the simplicity of their structure. Bacteria are primitive forms of life and can be assumed to have arisen at the earliest stages of the development of life on Earth. Bacteria originally lived in the seas. Modern microorganisms originated from them. Man became acquainted with the world of microbes after making a lens with high magnification.

« Origin and initial stages of the origin of life"

I. 1.What the theory of abiogenesis states: a) spontaneous origin of life; b) the origin of life; c) the possibility of the origin of living things from non-living things; d) development of inanimate matter.

2. What is the essence of Richter’s theory: a) the emergence of life from a gas-dust cloud; b) life on Earth arose from inorganic substances;

c) life was brought from other planets;

d) life arose from nonliving substances

3. What was the nature of ancient people’s ideas about the origin of life: a) chaotic; b) spontaneously materialistic; c) methodical;

d) scientific

4. What does the term “spectroscopy” mean: a) a point on a straight line; b) the most important point of contact between astronomy and chemistry; c) spectral analysis;

d) study of the spectrum

5. Protostars are: a) clouds; b) clouds; c) stars; d) planets

6. What chemical element is included in the composition of stellar and solar matter: a) barium; b) chlorine; c) hydrogen; d) oxygen

7. What is the great merit of A. Oparin’s theory in: a) the creation of the coacervate theory; b) concentrations of chemicals; c) in the difference between speed and time; d) obtaining organic substances

8. Who obtained amino acids: a) Haeckel and Muller;

b) Aristotle and Empedocles; c) Yuri and Miller;

d) Pasteur and Pflueger

9. Coacervates are: a) molecules surrounded by a dense shell;

b) molecules surrounded by an aqueous shell, which are combined into multimolecular complexes; c) macromolecules that break down into monomers; d) molecules that burn in atmospheric oxygen

10. Organic substances that do not dissolve in water are called:

a) hydrophobic; b) hydration; c) hydrogenated; d) hydrophilic

11. The essence of the photosynthesis process is: a) metabolism;

b) in the transport of substances; c) synthesis of organic substances; d) presence of vacuoles

12.An important substance necessary for the process of photosynthesis:

a) the presence of leukoplasts; b) the presence of chloroplasts; c) presence of a karyotype;

d) the presence of a plasma membrane

13. What applies to autotrophic organisms: a) bacteria; b) plants;

c) mushrooms; d) animals

14. Bacteria living in an oxygen-free environment are called: a) anaerobic;

b) protobionts; c) aerobic; d) autotrophic

15. Phagocytosis is the process of: a) absorption of liquid products;

b) release of carbon dioxide; c) absorption of solid particles;

d) metabolism

II. Choose the correct ones from the proposed judgments.

The theory of abiogenesis assumes the possibility of the origin of living things only from living things.

L. Pasteur with his experiments proved the possibility of spontaneous generation of life.

The most significant feature of A.I. Oparin’s hypothesis is the gradual complication of the chemical structure and morphological exchange of the precursors of life on the way to living organisms.

The lowest and most ancient level of life organization is the cellular level of life.

Coacervates are not able to adsorb substances from the solution surrounding them.

The body is a complex system capable of self-regulation.

Coacervates are the first ancient living creatures.

Life arose biogenically.

Living things are characterized by the ability for historical development and change from simple to complex.

L. Pasteur, with his experiments, proved the impossibility of the spontaneous generation of life.

III. Match.

A – abiogenesis. B – Oparin’s hypothesis. B – coacervates. G – open system. D – heterotrophs. E – autotrophs. F – biogeochemistry. Z – life. And - death. K – planet.

Heavenly body.

The emergence of living bodies from substances of inorganic nature.

A method of existence of protein bodies, the essential point of which is the constant exchange of substances with their surrounding environment.

The formation of organic substances from inorganic ones occurred in the waters of the primary ocean more than 3.5 billion years ago, while in an oxygen-free environment the atmosphere was saturated with aldehydes, alcohol, and amino acids.

Liquid bubbles surrounded by protein films.

Living body.

Organisms that synthesize organic substances necessary for life from inorganic ones.

A science that studies the chemical composition of living matter and the geochemical processes that constantly occur in the biosphere with the participation of living organisms.

Organisms that use ready-made organic substances for their nutrition.

Death of an individual in a population.

Answers: 1c, 2c, 3b, 4b, 5a, 6c, 7a, 8c, 9b, 10a, 11c, 12b, 13b, 14c, 15c

Answers: 3,6,10

Answers: 1-k, 2-a, 3-z, 4-b, 5-c, 6-d, 7-e, 8-g, 9-d, 10-i.