A living organism is a complex system consisting of interrelated organs and tissues. But why they say that the body is an open system.? For open systems, the exchange of anything with the external environment is characterized. This may be the metabolism, energy, information. And all these live organisms exchange with the external world for them. Although the word "exchange" is more appropriate to replace the word "stream", since the organism includes some substances and energy, and others come out.
Energy is absorbed by alive organisms in one form (plants - in the form of solar radiation, animals - in chemical bonds of organic compounds), and stands out to the environment in another (thermal). Since the body gets from the outside and highlights it, it is an open system.
In heterotrophic organisms, energy is absorbed together with substances (in which it is concluded) as a result of nutrition. Next, in the process of metabolism (metabolism inside the organism), some substances are split, and others are synthesized. In case of chemical reactions, energy is released (running on various processes of vital activity) and the energy is absorbed (going on the synthesis of the necessary organic substances). Unnecessary organism of the substance and the resulting thermal energy (which cannot be used) is allocated to the environment.
AutoTrophic (mainly plants) are absorbed as light rays as an energy in a certain range, and water, carbon dioxide, various mineral salts, oxygen are absorbed as the starting materials by them. Using energy and these mineral substances, plants as a result of the photosynthesis process carry out the primary synthesis of organic substances. In this case, radiant energy is maintained in chemical bonds. The plants have no excretory system. However, they identify substances with their surface (gases), throwing foliage (harmful organic and mineral substances are removed), etc. Thus, plants like living organisms are also open systems. They allocate and absorb substances.
Living organisms live in habitat characteristic. At the same time, to survive, they must adapt to the environment, respond not to its changes, look for food and avoid a threat. As a result, in the process of evolution, animals developed special receptors, sense organs, nervous system, which allow to obtain information from the external environment, process it and react, that is, to affect the environment. Thus, it can be said that the organisms have an exchange of information from an external habitat. That is, the body is an open information system.
Plants also react to the effects of the external environment (for example, closed the dust in the sun, turn the leaves to the light and others). In plants, primitive animal and mushrooms, regulation is carried out only with a chemical way (humoral). In animals having a nervous system, there are both methods of self-regulation (nervous and with hormones).
Unicellular organisms are also open systems. They feed and identify substances, react to external influences. However, in their body, the function of the organs of in-essence organs perform cell organelles.
"Conducting an open lesson" - a general discussion. We are needed to add an analysis made by the teacher. Teacher's answers to the class of lesson. Analysis of the lesson by the teacher. Representation of the teacher of the lesson project. Why do you need such preparatory work? Conduct an open lesson. Final generalization of the teacher. Teacher's answers to questions present.
"An open lesson for reading" - already in 1037 in ancient Russia, Yaroslav Wise was founded by the library. Now - 65 place. Currently, the works of fiction reads only 40% of the 14-year-old citizens of Russia. Pleasant reading! Until the middle of the twentieth century, our country was the most reading in the world. Jim Corbett - Cuman Cannibals Ivan Efremov - on the edge of Okumen Mikhail Bulgakov - Dog's heart Konstantin Poist - Meshchersky side.
"An open lesson in English" - pigs boasts, which knows everything about animals. Tom 7 I can run, jump. Decipher pictures. The subject of the lesson: "In the Magic Forest" "In The Magic Forest". Help Peter to present artists.
"Open occupation" is an organizational test primary final reflexive. Follow the tempo and time of classes. Enter into the case, put the beginning of something. Determine the necessary didactic, demonstration, distribution materials and equipment. Consider the activities of students at different stages of classes.
"Open lesson" is the purpose of the open lesson. Evaluation of the efficiency of the open lesson. "Raisin" in the lesson. Open lesson - ... Preparation for an open lesson. Criteria for evaluating an open lesson. A good marker praised a teacher's smile joy from self-solving a difficult task. "The moment of joy" in the lesson. For whom?
"Open lesson reading class 2" - inhabitable - draw up an act (document). Read correctly. Hheeight Green Beshechka Blind Tooth Falls Fall Out. Speech therapist. A funny good inquisitive. Check yourself! Find errors in words. Open lesson reading in grade 2. Viktor Yuzfovich Dragunsky (1913-1972). Which of the figures better reflect the mood of the story?
Chapter 1. Properties and origin of life1.1. Item, Tasks and methods of biology
Biology (Greek. Bio - Life and Logos - Knowledge, Teaching, Science) - Science of living organism. The variety of wildlife is so large that modern biology is a complex of sciences (biological sciences), significantly different from one another. At the same time, each has its own subject of study, methods, goals and objectives. For example, virology - science of viruses, microbiology - science of microorganisms, mycology - science of mushrooms, botany (phytology) - science of plants, zoology - science of animals, anthropology - science about man, cytology - science about cells, histology - science On the tissues, anatomy - the science of the inner structure, morphology - the science of the external structure, physiology - the science of the vital activity of the holistic organism and its parts, genetics - the science of the laws of heredity and variability of organisms and methods of management of them, ecology - science on the relationship of living organisms between and the environment surrounding them, the theory of evolution - the science on the historical development of wildlife, Paleontology is the science of life development in past geological times, biochemistry - science of chemicals and processes in living organisms; Biophysics - Science of physical and physicochemical phenomena in living organisms, biotechnology - a set of industrial methods that allow the use of living organisms and their individual parts for the production of valuable products (amino acids, proteins, vitamins, enzymes, antibiotics, hormones, etc.) etc.
Biology belongs to a complex of natural sciences, that is, sciences about nature. It is closely related to the fundamental sciences (mathematics, physics, chemistry), natural (geology, geography, soil science), public (psychology, sociology), applied (biotechnology, crop production, protection of nature).
Biological knowledge is used in the food industry, pharmacology, agriculture. Biology is theoretical basis of such sciences as medicine, psychology, sociology.
Achievements of biology should be used in solving global problems of modernity: the relationship between the society with the environment, rational nature management and the protection of nature, food supply.
Methods of biological research:
The method of observation and descriptions (lies in the collection and description of the facts);
A comparative method (lies in the analysis of the similarities and differences of the objects under study);
The historical method (studies the course of development of the object under study);
the method of the experiment (allows to study the phenomena of nature under specified conditions);
The modeling method (allows complex natural phenomena to describe relatively simple models).
1.2. Properties of live matter
Domestic scientist M.V. Wolkenstein proposed the following definition: "Live bodies that exist on Earth are open, self-regulating and self-reproducing systems constructed from biopolymers - proteins and nucleic acids."
However, the generally accepted definition of the concept of "life" does not exist, but it is possible to distinguish signs (properties) of living matters that distinguish it from inanimate.
1. Defined chemical composition. Live organisms consist of the same chemical elements as objects of inanimate nature, but the ratio of these elements is different. The main elements of living beings are C, O, N and N.
2. Board structure. All living organisms, except for viruses, have a cellular structure.
3. Cases of substances and energy dependence. Live organisms are open systems, they depend on the receipt of substances and energy from the external environment.
4.Same adjustment. Living organisms have the ability to maintain the constancy of their chemical composition and the intensity of metabolic processes.
5.Pright and mental functions. Living organisms show irritable, that is, the ability to respond to certain external influences with specific reactions.
6. Nestly. Living organisms are able to transmit signs and properties from generation to generation using media - DNA molecules and RNA.
7. Changeability. Living organisms can acquire new features and properties.
8.Same reproduction (reproduction). Live organisms are able to multiply - to reproduce themselves like.
9. Individual development. Ontogenesis - the development of the body from the moment of birth to death. Development is accompanied by growth.
10. Evolutionary development. Philogenesis - the development of life on earth from the moment of its emergence so far.
11. Herdity. Living organisms show the rhythm of vital activity (daily, seasonal, etc.), which is associated with the features of the habitat.
12. Assumption and discreteness. On the one hand, all living matter is intertwined in a certain way organized and obeys general laws; On the other hand, any biological system consists of separate, albeit interrelated elements.
13.Rerry. Starting from biopolymers (nucleic acids, proteins) to the biosphere as a whole, everything alive is in a certain cooding. The functioning of biological systems at a less complex level makes it possible to exist a more complex level (see the next paragraph).
1.3. Living nature levels
The hierarchy of the organization of living matter allows to conventionally divided it into a number of levels. The level of organization of live matter is the functional place of the biological structure of a certain degree of complexity in the general hierarchy of the living. Allocate the following levels:
1. Molecular (molecular genetic). At this level, such processes of vital activity are manifested as the metabolism and the transformation of energy, the transfer of hereditary information.
2. cell. The cell is an elementary structural and functional unit of the living.
3. Cyneva. The fabric is a set of structurally similar cells, as well as associated intercellular substances, combined with certain functions.
4. Organized. The organ is part of a multicellular body that performs a specific function or function.
5. Organized. The body is a real carrier of life characterized by all its signs. Currently, a single "ontogenetic" level, including cellular, tissue, organ and organized levels of organization, is often distinguished.
6.Population-species. The population is a set of individuals of one species forming a separate genetic system and inhabitable space with relatively homogeneous habitat. The form is a set of populations, the individuals of which are capable of crossing with the formation of fruit offspring and occupy a certain area of \u200b\u200bgeographical space (range).
7.Biocenotic. Biocenosis is a set of organisms of different types of various complexity of the organization living in a certain territory. If the abyotic habitat factors are also taken into account, they are talking about biogeocenosis.
8.Biosphere. The biosphere is the land shell, the structure and properties of which to one degree or another are determined by the present or last operation of living organisms. It should be noted that the biosphere level of the organization of living matters is often not isolated, since the biosphere is a biocosal system, which includes not only a living agent, but also inanimate.
1.4. The origin of life
On the issue of the origin of life, just as on the issue of the essence of life among scientists there is no consensus. There are several approaches to solving the issue of the origin of life, which are closely intertwined with each other. It is possible to classify them as follows.
1. Only the principle that the idea, the mind is prim than, and the matter is secondary (idealistic hypotheses) or matter primary, and the idea, the mind is secondary (materialistic hypothesis).
2. Only the principle that life always existed and will exist forever (hypotheses of a stationary state) or life arises at a certain stage of the development of the world.
3. Only the principle - alive only on the living (hypothesis of biogenesis) or possibly the self-sensitive of the living from the non-living (hypothesis of abiogenesis).
4. In the principle of life on Earth or was listed from the space (Parisermia hypothesis).
Consider the most significant of the hypotheses.
Creationism. Life was created by the Creator. The Creator is God, the idea, the highest mind or others.
Hypothesis of stationary state. Life, like the Universe itself, there always existed and will exist forever, for not the beginning does not have the end. At the same time, the existence of individual bodies and formations (stars, planets, organisms) is limited in time, they arise, are born and dying. Currently, this hypothesis has mainly historical importance, since the generally accepted theory of education of the universe is the "Theory of the Big Explosion", according to which the Universe is a limited time, it formed from one point about 15 billion years ago.
Hypothesis Panxermia. Life on the ground was listed from the space, and passed here, after the condition was favorable for this. Solving the issue of how life arose in space, due to the objective difficulties of his decision, moved indefinitely. She could be created by the Creator, to exist always or arise from inanimate matter. Recently, among scientists, more and more supporters of this hypothesis appear.
Hypothesis of abogenesis (self-timing of a living non-living and subsequent biochemical evolution). Life originated on Earth from inanimate matter.
In 1924 A.I. Oparin suggested that living arose on Earth from inanimate matter as a result of chemical evolution - complex chemical transformations of molecules. This event favored the conditions at the time on earth conditions.
In 1953, S. Miller in laboratory conditions received a number of organic substances from inorganic compounds. The principal possibility of the inorganic path of the formation of biogenic organic compounds (but not living organisms) was proved.
A.I. Oparin believed that organic substances could be created in the primary ocean from simple inorganic connections. As a result of the accumulation in the ocean of organic substances, the so-called "primary broth" was formed. Then, uniting, proteins and other organic molecules were formed by a drop of coactervats, which served as the prototype of cells. Cacerta droplets were subjected to natural selection and evolved. The first organisms were heterotrophic. As the stocks of the "primary broth" exhausted the authotrophic.
It should be noted that in terms of the theory of probability, the likelihood of the synthesis of ultra-lined biomolecules under the condition of random compounds of their component parts is extremely low.
IN AND. Vernadsky on the origin and essence of life and the biosphere. IN AND. Vernadsky outlined his views on the origin of life in the following theses:
1. Incidentally, in that space, which we observe, was not, because there was no beginning of this space. Life is eternal, because it is eternal space, and has always been transmitted by biogenesis.
2. Job, writing an eternally inherent in the universe, was new on earth, her embryos were brought from the outside, but they were strengthened on Earth only with favorable opportunities.
3. Was always on Earth. The existence of the planet is only the time of existence on it of life. The life of geologically (planetary) is eternal. The age of the planet is indefunny.
4. The day was never something random in some separate oases. It was distributed everywhere and always a living thing existed in the image of the biosphere.
Five years of living forms - shotguns - can perform all functions in the biosphere. So, a biosphere is possible, consisting of some prokaryotes. It is likely that she was in the past.
6. There could not happen from the oblique. There are no intermediate steps between these two states. On the contrary, as a result of the impact of life, the evolution of the earth's crust occurred.
Thus, it is necessary to recognize the fact that by now none of the existing hypotheses of the origin of life has direct evidence, and modern science has no definite answer to this question.
Chapter 2. Chemical composition of living organisms
2.1. Elemental composition
The chemical composition of living organisms can be expressed in two types: atomic and molecular. Atomic (elemental) composition characterizes the ratio of atoms of elements included in living organisms. Molecular (real) composition reflects the ratio of molecules of substances.
For relative content, elements included in living organisms, it is customary to divide into three groups:
1. Machine elements - H, O, C, N (in the amount of about 98%, they are also called the main), CA, CL, K, S, P, MG, NA, FE (in the amount of about 2%). Macroelements constitute the bulk of the percentage of living organisms.
2.Microelements - Mn, CO, Zn, Cu, B, I, etc. Their total content in the cell is about 0.1%.
3. Tertramicroelements - AU, HG, SE, etc. Their content in the cell is very slightly, and the physiological role for most of them is not disclosed.
Chemical elements that are part of living organisms and at the same time perform biological functions, called biogenic. Even those that are contained in the cells in negligible quantities, can no longer be replaced and absolutely necessary for life.
2.2. Molecular composition
Chemical elements are included in the cells in the form of ions and molecules of inorganic and organic substances. The most important inorganic substances in the cell - water and mineral salts, the most important organic substances - carbohydrates, lipids, proteins and nucleic acids.
2.2.1. Inorganic substances
2.2.1.1. Water
Water is the predominant component of all living organisms. It has unique properties due to the characteristics of the structure: water molecules have the form of a dipole and hydrogen bonds are formed between them. The average water content in the cells of most living organisms is about 70%. Water in the cage is present in two forms: free (95% of all the water of the cell) and the associated (4-5% are associated with proteins).
Water functions:
1. Support as a solvent. Many chemical reactions in the cell are ionic, therefore proceed only in the aquatic environment. Substances dissolving in water are called hydrophilic (alcohols, sugar, aldehydes, amino acids), non-soluble - hydrophobic (fatty acids, cellulose).
2. Support as a reagent. Water participates in many chemical reactions: polymerization reactions, hydrolysis, in the process of photosynthesis.
3. Transport function. Movement in the body together with water dissolved in it to different parts of its parts and the elimination of unnecessary products from the body.
4. Support as a thermostabilizer and thermostat. This function is due to such properties of water as high heat capacity - mitigates the effect on the body of significant temperature differences in the environment; High thermal conductivity - allows the body to maintain the same temperature in all its volume; High evaporation heat - used to cool the organism during sweating in mammals and transpiration in plants.
5. Structural feature. Cell cytoplasm contains from 60 to 95% water, and it is it that gives the cells to the cells. In plants, water supports the tour (elasticity of the endoplasmic membrane), in some animals serves as a hydrostatic skeleton (jellyfish).
2.2.1.2. Mineral salts
Mineral salts in an aqueous cell solution dissociate into cations and anions. The most important cations - K +, Ca2 +, Mg2 +, Na +, NH4 +, Anions are CL-, SO42-, HPO42-, H2PO4-, HCO3-, NO3-. Essential is not only a concentration, but also the ratio of individual ions in the cell.
Mineral functions:
1. Draft acid-alkaline equilibrium. The most important buffer mammalian systems are phosphate and bicarbonate. The phosphate buffer system (HPO42-, H2PO4-) supports the pH of the intracellular fluid in the range of 6.9-7.4. The bicarbonate system (HCO3-, H2CO3) retains the pH of the extracellular medium (blood plasma) at 7.4.
2. Equipment in the creation of membrane cell potentials. Inside the cells, ions K + and large organic ions are dominated, and in the near-cell fluids larger than Na + and Cl- ions. As a result, the difference in charges (potentials) of the outer and inner surfaces of the cell membrane is formed. The potential difference makes it possible to transmit excitation by nerve or muscle.
3. Activation of enzymes. Ca2 +, Mg2 + ions, etc. are activators and components of many enzymes, hormones and vitamins.
4. Creation of osmotic pressure in the cell. The higher concentration of salt ions inside the cell provides water flow and the creation of tour pressure.
5.Construction (structural). Nitrogen, phosphorus, calcium compounds and other inorganic substances serve as a source of building material for the synthesis of organic molecules (amino acids, proteins, nucleic acids, etc.) and are part of a number of supporting cells of the cell and the body. Calcium and phosphorus salts are part of the bone tissue of animals.
2.2.2. Organic substances
The concept of biopolymers. The polymer is a multi-sided chain in which the link is a relatively simple substance - a monomer. Biological polymers are polymers included in the cells of living organisms and their livelihoods. Biopolymers are proteins, nucleic acids, polysaccharides.
2.2.2.1. Carbohydrates
Carbohydrates are organic compounds consisting of one or many molecules of simple sugars. The content of carbohydrates in animal cells is 1-5%, and in some plants, 70% reaches. Three groups of carbohydrates are isolated: monosaccharides (or simple sugar), oligosaccharides (consist of 2-10 molecules of simple sugars), polysaccharides (consist of more than 10 sugars molecules).
Monosaccharides are ketone or aldehyde derivatives of polyhydric alcohols. Depending on the number of carbon atoms, triosis, tetroza, pentoses (ribose, deoxyribosis), hexoses (glucose, fructose) and heptose are distinguished. Depending on the functional group of sugar, they are divided into: aldose, having a aldehyde group (glucose, ribose, deoxyribosis), and ketosis with a keton group (fructose).
Oligosaccharides in nature are mostly represented by disaccharides consisting of two monosaccharides associated with each other with a glycoside. Maltose, or malt sugar, consisting of two glucose molecules; lactose, which is part of milk and consisting of galactose and glucose; Sakharoza, or beet sugar, including glucose and fructose.
Polysaccharides. In polysaccharides, simple sugar (glucose, mannose, galactose, etc.) are interconnected by glycosidic connections. If only 1-4 glycosida bonds are present, a linear, unbranched polymer (cellulose) is formed if 1-4, and 1-6 communications are present, the polymer will be branched (glycogen).
Cellulose - linear polysaccharide consisting of molecules-glocose. Cellulose is the main component of the cell wall of plants. Starch and glycogen branched polymers from glucose residues are the main forms of glucose pans in plants and animals, respectively. Chitin forms an outer skeleton in crustaceans and insects (shell), the mushroom has the strength of the cell wall.
Functions of carbohydrates:
1. Energy. When oxidizing simple sugars (primarily glucose), the body receives the main part of the energy you need. With full splitting 1 g of glucose, 17.6 kJ of energy is released.
2. Overweight. Starch and glycogen plays the role of a glucose source, releaseing it as needed.
3.Construction (structural). Cellulose and chitin give the strength of the cell walls of plants and mushrooms, respectively. Ribose and deoxyribosis are included in nucleic acids.
4. Receptor. The function of recognition by cells of each other is provided by glycoproteins that are part of cell membranes. The loss of the ability to recognize each other is characteristic of cells of malignant tumors.
2.2.2.2. Lipids
Lipids - fats and leaf-like organic compounds, practically insoluble in water. Their content in different cells varies greatly: from 2-3 to 50-90% in plant seed cells and animal adipose tissue. In the chemical ratio of lipids, as a rule, esters of fatty acids and a number of alcohols. They are divided into several classes: neutral fats, wax, phospholipids, steroids, etc.
Lipid functions:
1. Construction (structural). Phospholipids together with proteins are the basis of biological membranes. Cholesterol is an important component of cell membranes in animals.
2.Gormonal (regulatory). Many chemical nature hormones are steroids (testosterone, progesterone, cortisone).
3. Energy. In the oxidation of 1 g of fatty acids, 38 kJ of energy is released and is synthesized twice the amount of ATP, than when splitting the same amount of glucose.
4.Faspay. In the form of fats there is a significant part of the body's energy reserves. In addition, fats serve as a source of water (when combustion 1 g of fat is formed 1.1 g of water). This is especially valuable for desert and arctic animals experiencing a shortage of free water.
5. Protection. In mammals, subcutaneous fat acts as a thermal insulator. The wax covers the epidermis of plants, feathers, wool, animal hair, preventing wetting.
6.Expiration in metabolism. Vitamin D plays a key role in the exchange of calcium and phosphorus.
2.2.2.3. Proteins
Proteins are biological heteropolymers whose monomers are amino acids.
According to the chemical composition of amino acids - these are compounds containing one carboxyl group (-son) and one amine (-NH2) associated with one carbon atom, to which the side chain is attached - some radical R (it is it gives an amino acid of its unique properties) .
Only 20 amino acids participate in the formation of proteins. They are called fundamental or basic: alanine, methionine, valine, proline, leucine, isoleucine, tryptophan, phenylalanine, asparagin, glutamine, serine, glycine, tyrosine, threonine, cysteine, arginine, histidine, lysine, aspartic and glutamic acid. Some of the amino acids are not synthesized in animal and human organisms and should act with vegetable food (they are called indispensable).
Amino acids, connecting with each other covalent peptide bonds, form different peptide lengths. The peptide (amide) is called a covalent bond formed by a carboxyl group of one amino acid and an amine group of another. Proteins are high molecular weight polypeptides, which include from a hundred to several thousand amino acids.
4 levels of the organization of proteins are highlighted:
The primary structure is the sequence of amino acids in the polypeptide chain. It is formed at the expense of covalent peptide ties between the amino acid residues. The primary structure is determined by the nucleotide sequence in the DNA molecule section encoding this protein. The primary structure of any protein is unique and determines its shape, properties and functions.
The secondary structure is formed by laying polypeptide chains in -spioral or -structure. It is maintained by hydrogen bonds between hydrogen atoms of NH- \u200b\u200band oxygen atoms of the SO-group. -Spiral is formed as a result of twisting of the polypeptide chain into a spiral with the same distances between the turns. It is characteristic of globular proteins having a spherical form of globule. -Thestructure is a longitudinal laying of three polypeptide chains. It is characteristic of fibrillar proteins having an elongated fibril shape. Tertiary and quaternary structures have only globular proteins.
The tertiary structure is formed when folding the spirals in the ball (globe, or domain). Domains - global-like formations with a hydrophobic core and hydrophilic outer layer. The tertiary structure is formed by bonds generated between radicals R amino acids due to ionic, hydrophobic and dispersion interactions, as well as by the formation of disulfide (S-S) bonds between cysteine \u200b\u200bradicals.
The quaternary structure is characteristic of complex proteins consisting of two and more polypeptide chains that are not associated with covalent bonds, as well as for proteins containing non-protein components (metal ions, coenses). The quaternary structure is supported by the same chemical bonds, as well as tertiary.
The protein configuration depends on the sequence of amino acids, but the specific conditions in which protein is located can be influenced.
The loss of a protein molecule of its structural organization is called denaturation. Denaturation can be reversible and irreversible. With reversible denaturation, a quaternary, tertiary and secondary structure is destroyed, but due to the preservation of the primary structure, with the return of normal conditions, the protein is possible - the restoration of normal (native) conformation.
By chemical composition distinguish simple and complex proteins. Simple proteins consist only of amino acids (fibrillar proteins, immunoglobulins). Sophisticated proteins contain protein part and non-protein - prosthetic groups. Lipoproteins are distinguished (contain lipids), glycoproteins (carbohydrates), phosphoprotein (one or more phosphate groups), metalloproteins (various metals), nucleoproteins (nucleic acids). Protection groups usually play an important role when performing its biological function protected.
Protein features:
1.Catalogic (enzymatic). All enzymes are proteins. Proteins-enzymes catalyze leakage in the body of chemical reactions.
2.Construction (structural). It is carried out by fibrillar proteins of keratin (nails, hair), collagen (tendon), elastin (ligaments).
3. Transport. A number of proteins are able to attach and transfer various substances (hemoglobin transfers oxygen).
4.Gormonal (regulatory). Many hormones are protein nature substances (insulin regulates glucose exchange).
5. Protection. Immunoglobulins of blood are antibodies; Fibrin and thrombin are involved in blood clotting.
6.Secretive (motor). Aktin and Mozin form microfulamen and reduce the muscles, tubulin forms microtubules.
7.receptor (signal). Some proteins embedded in the membrane "perceive information" from the environment.
8.Energetic. When splitting 1 g of proteins is released 17.6 kJ of energy.
Enzymes. Proteins-enzymes catalyze leakage in the body of chemical reactions. These reactions due to energy reasons by themselves either do not flow in the body at all, or flow too slowly.
In its biochemical nature, all enzymes are high molecular weight protein substances, usually a quaternary structure. All enzymes in addition to the protein contain non-protein components. The protein part is called the apochempant, and the non-refinery is a cofactor (if it is a simple inorganic substance, for example, Zn2 +) or a coenzyme (coenzyme) (if it is an organic compound).
In the enzyme molecule, there is an active center consisting of two sites - the sorption (responsible for the binding of the enzyme with the substrate molecule) and the catalytic (responsible for the flow of the catalysis itself). During the reaction, the enzyme binds the substrate, consistently changes its configuration, forming a number of intermediate molecules that ultimately give the reaction products.
The difference of enzymes from the catalysts of inorganic nature is as follows:
1.Dine enzyme catalyzes only one type of reaction.
2. The activeness of enzymes is limited by a rather narrow temperature frame (usually 35-45 0 ° C).
3. The antimensions are active at certain pH values \u200b\u200b(most in a weakly alkaline medium).
2.2.2.4. Nucleic acids
Mononucleotides. The mononucleotide consists of one purin (adenine a, guanine - d) or pyrimidine (cytosine - c, tamin - t, uracil - y) of a nitrogen base, sugar-pentoses (ribose or deoxyribosis) and 1-3 phosphoric acid residues.
Polynucleotides. There are two types of nucleic acids: DNA and RNA. Nucleic acids - polymers whose monomers serve nucleotides.
DNA and RNA nucleotides consist of the following components:
1.Azotic base (in DNA: adenine, guanine, cytosine and thymine; in RNA: adenine, guanine, cytosine and uracil).
2.Sahar-pentezza (in DNA - deoxyribosis, in RNA - Rboma).
3.Ostate phosphoric acid.
DNA (deoxyribonucleic acids) is a long chain unbranched polymer consisting of four types of monomers - nucleotides A, T, G, and C - associated with each other covalent bond through the residues of phosphoric acid.
The DNA molecule consists of two spiral swirling chains (double spiral). At the same time, adenine forms 2 hydrogen bonds with thimine, and guanine - 3 connections with a cytosine. These pairs of nitrogen bases are called complementary. In the DNA molecule, they are always located opposite each other. The chains in the DNA molecule are oppositely directed. The spatial structure of the DNA molecule was installed in 1953 D. Watson and F. Cry.
Touching the DNA molecule proteins forms chromosome. Chromosome - complex one DNA molecule with proteins. DNA molecules of eukaryotic organisms (mushrooms, plants and animals) are linear, unlocked, associated with proteins, forming chromosomes. Prokaryott (bacteria) is closed in a ring, not related to proteins, does not forms a linear chromosome.
DNA function: storage, transmission and reproduction in a number of generations of genetic information. DNA determines which proteins and in what quantities it is necessary to synthesize.
RNA (ribonucleic acids) instead of deoxyribose contain ribosa, and instead of Timine - Uracil. RNA, as a rule, have only one chain, shorter than DNA chains. Two-chain RNA meet some viruses.
Types of RNA:
Information (matrix) RNA - IRNA (or MRNA). It has an impaired chain. It serves as matrices for protein synthesis, transferring information about their structure with DNA molecule to ribosomams in the cytoplasm.
Transport RNA - TRNA. Delivers amino acids to a synthesized protein molecule. The TRNA molecule consists of 70-90 nucleotides and thanks to intrahepken complementary interactions, it acquires a characteristic secondary structure in the form of a "clover sheet".
Ribosomal RNA - RRNA. In the complex with ribosomal proteins, it forms ribosomes - organelles, on which protein synthesis occurs.
The cage to the share of MRNA accounts for about 5%, TRNA - about 10%, and RRNA is about 85% of the entire cell RNA.
RNA functions: participation in the biosynthesis of proteins.
DNA self-esteem. DNA molecules have the ability to disappointing any other molecule - ability to doubl. The process of doubling DNA molecules is called replication. Replication is based on the principle of complementarity - the formation of hydrogen bonds between nucleotides A and T, G and C.
This process is carried out by DNA polymerase enzymes. Under their effects of the DNA molecule chain are separated on a small segment of the molecule. Daughter chains are completed on the chain molecule. Then the new segment is broken and the replication cycle is repeated.
As a result, daughter DNA molecules are formed, no different from each other and from the mother molecule. In the process of dividing the cell, daughter DNA molecules are distributed between the cells generated. This is how information is transferred from generation to generation.
Chapter 3. Cell Build
The main provisions of the cell theory:
1. The cell is a structural unit of all alive. All living organisms consist of cells (the exception is viruses).
2. The cell is a functional unit of all alive. The cell manifests the entire complex of life functions.
3. The cell is a unit of development of all living things. New cells are formed only as a result of the division of the original (maternal) cell.
4. The cell is a genetic unit of all alive. In cell chromosomes, information on the development of the whole organism is contained.
5. The cells of all organisms are similar to the chemical composition, structure and functions.
3.1. Types of cell organization
Among living organisms, only viruses do not have a cellular structure. All other organisms are represented by cellular forms of life. There are two types of cell organization: prokaryotic and eukaryotic. Prokaryotm includes bacteria and bluenelen, to eukaryotes - plants, mushrooms and animals.
Prokaryotic cells are arranged relatively simply. They do not have a nucleus, the area of \u200b\u200bthe DNA location in the cytoplasm is called a nucleoid, the only DNA molecule is ring and not associated with proteins, the cells are less than eukaryotic, in the composition of the cell wall included glycopeptide - Murein, membrane organelles are missing, their functions are filled with plasma membrane, ribosomes are small, Microtubules are absent, therefore the cytoplasm is fixed, and cilia and flagellas have a special structure.
Eukaryotic cells have a kernel in which the chromosomes are located - linear DNA molecules associated with proteins, various membrane organelles are located in the cytoplasm.
Vegetable cells are distinguished by the presence of a thick cellulose cell wall, a plastic, a large central vacuole that displaced the kernel to the periphery. The cell center of higher plants does not contain centrioles. A spare carbohydrate is starch.
Mushroom cells have a cell shell containing chitin, in the cytoplasm there is a central vacuol, there are no plasts. Only some fungi in the cell center occurs in Centril. The main reserve carbohydrate is glycogen.
Animal cells have, as a rule, a thin cell wall, do not contain plastic and central vacuole, for the cellular center is characterized by centriole. A spare carbohydrate is glycogen.
3.2. The structure of the eukaryotic cell
All cells consist of three main parts:
1. The cell shell limits the environment from the environment.
2. The cytoplasm is the internal content of the cell.
3. The kernel (in prokaryotic - nucleoid). Contains the genetic material of the cell.
3.2.1. Cell sheath
The structure of the cell shell. The base of the cell enclosure is the plasma membrane - a biological membrane that limits the internal content of the cell from the external environment.
All biological membranes are a double layer of lipids, the hydrophobic ends of which are facing inside, and the hydrophilic heads are outward. Proteins are immersed on different depths, some of which permeate the membrane through. Proteins are capable of moving in the plane of the membrane. Membrane proteins perform various functions: transport of various molecules; obtaining and converting signals from the environment; Maintaining membrane structure. The most important property of membranes is selective permeability.
Plasma membranes of animal cells have an outside of a glycocalca layer consisting of glycoproteins and glycolipids, and performing signal and receptor function. It plays an important role in combining cells in fabric. Plasma membranes of vegetable cells are covered with cellulose cellular wall. Pores in the wall allow you to pass water and small molecules, and the stiffness provides a mechanical support and protection cell.
Functions of the cell shell. The cell shell performs the following functions: determines and maintains the shape of the cell; protects the cell from mechanical effects and penetration of damaging biological agents; degrades the internal contents of the cell; regulates the metabolism between the cell and the environment, ensuring the constancy of the intracellular composition; performs recognition of many molecular signals (for example, hormones); Participates in the formation of intercellular contacts and various kinds of specific protums of cytoplasm (microvascular, cilia, flagella).
The mechanisms of penetration of substances into the cell. There is a metabolism between the cell and the environment. Ions and small molecules are transported through a membrane by passive or active transport, macromolecules and large particles - by endo and exocytosis.
Passive transport - the movement of the substance according to the concentration gradient is carried out without energy costs, by simply diffusion, osmosis, or light diffusion using carrier proteins. Active transport - the transfer of a substance with proteins-carriers against a concentration gradient is associated with energy costs.
Endocytosis is the absorption of substances by environment of them with the growing plasma membrane with the formation of the surrounded membranes of bubbles. Exocytosis is the release of substances from the cell by environment of their plasma membrane growth with the formation of surrounded membrane bubbles. The absorption and separation of solid and large particles obtained, respectively, the names of phagocytosis and inverse phagocytosis, liquid or dissolved particles - pinocytosis and inverse pinocytosis.
3.2.2. Cytoplasm
The cytoplasm is an internal content of the cell and consists of a basic substance (hyaloplasm) and in it a variety of intracellular structures (inclusions and organoids).
Hyaloplasma (matrix) is an aqueous solution of inorganic and organic substances capable of changing its viscosity and in constant motion.
Cytoplasmic cell structures are represented by inclusions and organoids. Inclusion - non-permanent structure of cytoplasm in the form of granules (starch, glycogen, proteins) and drops (fats). Organoides are the permanent and mandatory components of most cells having a specific structure and perform vital functions.
Single-dimmable cell organides: endoplasmic reticulum, Golgji, Lizosoma plate.
The endoplasmic reticulum (network) is a system of interconnected cavities, tubes and channels derived from cytoplasm with one layer of membrane and separating cell cytoplasm on isolated spaces. It is necessary to separate the set of parallel reactions. The grungy endoplasmic reticulum is isolated (ribosomes are located on its surface, on which the protein is synthesized) and a smooth endoplasmic reticulum (on its surface the synthesis of lipids and carbohydrates is carried out).
The Machinery of the Golgi (plate complex) is a stack of 5-20 flattened disk-shaped membrane cavities and micropulosity seed from them. Its function is a transformation, accumulation, transport of substances entering it to various intracellular structures or beyond the cell. The membranes of the Golgi apparatus are capable of forming lysosomes.
Lizosomes - membrane bubbles containing lithic enzymes. In the lysosomes are digested both entering the cell by endocytosis products and composite parts of cells or cells of the entire (autolis). Distinguish primary and secondary lysosomes. Primary lysosomes are microfubbers, surrounded by a single membrane and containing a set of enzymes. After the fusion of primary lysosomes with the substrate to be cleaved, secondary lysosomes are formed (for example, digestive vacuoles of the simplest).
Vacuoles - liquid filled membrane bags. The membrane is called tonoplast, and the contents of cellular juice. In cellular juice there may be spare nutrients, solutions of pigments, life waste, hydrolytic enzymes. Vacuoles are involved in the regulation of water-salt metabolism, the creation of tour pressure, accumulation of spares and exchanging toxic compounds.
The endoplasmic network, the Golgi complex, lysosomes and vacuoles are single-dimmable structures and form a single membrane cell of the cell.
Two-paved cells of the cell: mitochondria and plastists.
Eukarot cells also have organelles isolated from cytoplasm with two membranes. These are mitochondria and plastids. They have their own ring molecule DNA, ribosomes of small size and are able to share. This served as the basis for the appearance of a symbiotic theory of eukaryotes. According to this theory, in the past, mitochondria and plastists were independent prokarotami, which turned later to endosimbiosis with other cellular organisms.
Mitochondria is organic chopper, oval or rounded form. The contents of mitochondria (matrix) is limited to the cytoplasm with two membranes: the outer smooth and inner forming folds (crystys). In mitochondria, ATP molecules are formed.
Plasts - Organly, surrounded by a shell consisting of two membranes, with a homogeneous substance inside (stroma). The plasts are characteristic only for cells of photosynthetic eukaryotic organisms. Depending on the painting, chloroplasts are distinguished, chromoplasts and leucoplasts.
Chloroplasts are green plastides in which the process of photosynthesis proceeds. Outdoor membrane smooth. Internal - forms a system of flat bubbles (thylacoids), which are assembled in stacks (marriages). Tylacoid membranes contain green chlorophyll pigments, as well as caratinoids. Chromoplasts - plasts containing pigments of caratinoids, giving them red, yellow and orange color. They give a bright color of flowers and fruits. Telecoplasts are unplanned, colorless plasts. It is contained in cells of underground or unpainted parts of plants (roots, rhizomes, tubers). Able to accumulate spare nutrients, primarily starch, lipids and proteins. The leukoplasts can turn into chloroplasts (for example, in flowering potato tubers), and chloroplasts in chromoplasts (for example, in the ripening of fruits).
Organoisides that do not have a membrane structure: ribosomes, microfilaments, microtubule, cellular center.
Ribosomes are small organelles, globular shapes consisting of proteins and RRNA. Ribosomes are represented by two subunits: big and small. They can either be fluent in cytoplasm, or attached to the endoplasmic reticulum. On ribosomes, protein synthesis occurs.
Microtubules and microfilaments are non-shaped structures consisting of contractile proteins and determine the motor functions of the cell. Microtubule have the form of long hollow cylinders, the walls of which consist of proteins - tubulins. Microfilaments are even thinner, long, filamentous structures consisting of actin and alone. Microtubule and microfilaments permeate the entire cytoplasm of the cell, forming its cytoskeleton, cause cyclosis (Current of cytoplasm), intracellular displacement of the organelle, form spine divisions, etc. In a certain way, organized microtubule, form central centers, basal tales, cilia, flagella.
The cell center (centrosoma) is usually located near the nucleus, consists of two centrioles located perpendicular to each other. Each Centralol has a kind of hollow cylinder, the wall of which is formed by 9 microtubule triplets. Centrioli play an important role in dividing the cell, forming spine divisions.
Flares and cilia are organides of the movement, which are peculiar increases of cytoplasm cells. The osters of the flagella or cilia has the form of a cylinder, on the perimeter of which 9 paired microtubes are located, and in the center - 2 single.
3.2.3. Nucleus
Most cells have one core, but multi-core cells are found (in a number of simplest vertebrates in skeletal muscles). Some highly specialized cells lose the nuclei (erythrocytes of mammals and cells of synthipal tubes in coated plants).
The kernel, as a rule, has a spheroid or oval shape. The kernel includes a nuclear sheath and a karyoplasm containing chromatin (chromosome) and nuclei.
The nuclear shell is formed by two membranes (external and internal). Holes in the nuclear shell are called nuclear pores. The metabolism between the core and the cytoplasma is carried out through them.
Karioplasma is the internal contents of the kernel.
Chromatin is an unbearable DNA molecule associated with proteins. In such a form, DNA is present in the underlying cells. It is possible to double DNA (replication) and the implementation of the information concluded in DNA. Chromosome - spiralized DNA molecule associated with proteins. DNA is spiralized before dividing the cell for a more accurate distribution of genetic material during division. At the metaphasis stage, each chromosome consists of two chromatids that are the result of DNA doubling. Chromatids are connected to each other in the primary hauling area, or centromers. The centrometer divides chromosomes into two shoulders. Some chromosomes have secondary bags.
Sadryshko is a spherical structure, the function of which is the synthesis of RRNA.
The functions of the kernel: 1. The storage of genetic information and the transfer of it to the daughter cells during the division. 2. Control of the vital cells of the cell.
Chapter 4. The metabolism and the conversion of energy
4.1. Types of food of living organisms
All living organisms living on Earth are open systems depending on the receipt of the substance and energy from the outside. The process of consumption of substance and energy is called power. Chemicals are necessary for body construction, energy - to carry out vital processes.
By the type of nutrition, living organisms are divided into autotrophs and heterotrophs.
Auto-organisms that use carbon dioxide (plants and some bacteria) as a source of carbon. In other words, these are organisms capable of creating organic substances from inorganic - carbon dioxide, water, mineral salts.
Depending on the energy source, autotrophs are divided into phototrofs and chemotrofs. Phototrophs - organisms using light energy for biosynthesis (plants, cyanobacteria). Chemotrofa - organisms using the energy of chemical reactions of oxidation of inorganic compounds (chemotrophic bacteria: hydrogen, nitrifying, ferruplan, sulfur, etc.).
Heterotrophs - organisms using organic compounds as a carbon source (animals, mushrooms and most bacteria).
By the method of obtaining food, heterotrophs are divided into phagotrophs (Golodyv) and examinations. FAGOTROFY (GOLODY) Solid slices of food (animals), the examiners absorb organic substances from the solutions directly through the cell walls (mushrooms, most bacteria).
Mixotrophs are organisms that can, like synthesize organic substances from inorganic and feed on ready-made organic compounds (insectivore plants, representatives of the Evglen algae department, etc.).
Table 1 shows the type of nutrition of large systematic groups of living organisms.
Table 1
Types of food of large systematic groups of living organisms
4.2. Concept of metabolism
Metabolism is a set of all chemical reactions occurring in a living organism. The value of metabolism is to create the necessary organisms of substances and providing its energy. Two components of metabolism - catabolism and anabolism are distinguished.
Catabolism (or energy exchange, or dissimilation) - a set of chemical reactions leading to the formation of simple substances from more complex (hydrolysis of polymers to monomers and splitting the latter to low molecular weight compounds of carbon dioxide, water, ammonia, etc. substances). Catabolic reactions usually go with energies.
Anabolism (or plastic exchange, or assimilation) - the concept opposite to catabolism is a set of chemical reactions of the synthesis of complex substances from the simpler (formation of carbohydrate carbohydrates and water in the process of photosynthesis, the reaction of matrix synthesis). Energy costs are required for the flow of anabolic reactions.
Plastic and energy exchange processes are inextricably linked. All synthetic (anabolic) processes need the energy supplied during the dismillation reactions. The reaction of splitting (catabolism) is proceeded only with the participation of enzymes synthesized during the assimilation process.
4.3. ATP and its role in metabolism
The energy released during the decay of organic substances is not immediately used by the cell, and is inhibited in the form of high-energy compounds, as a rule, in the form of adenosine trifhosphate (ATP).
ATP (adenosineryphosphoric acid) is a mononucleotide, consisting of adenine, ribose and three phosphoric acid residues that combined with macro-ergic bonds. In these connections, the energy that is released during their rupture are stored:
ATP + H2O -\u003e ADF + H3PO4 + Q1
ADF + H2O -\u003e AMF + H3PO4 + Q2
AMP + H2O -\u003e Adenin + Ribose + H3PO4 + Q3,
Where ATP is adenosineryphosphoric acid; ADF - adenosine hydrochlorophosphoric acid; AMP - adenosine monophosphoric acid; Q1 \u003d Q2 \u003d 30.6 kJ; Q3 \u003d 13.8 kJ.
The ATP stock in the cell is limited and is replenished due to the process of phosphorylation. Phosphorylation - addition of phosphoric acid residue to ADP (ADF + F ATP). The energy accumulated in ATP molecules is used by the body in anabolic reactions (biosynthesis reactions). ATP molecule is a universal keeper and energy carrier for all living beings.
4.4. Energy exchange
The energy required for life, most organisms are obtained as a result of the oxidation of organic substances, that is, as a result of catabolic reactions. The most important compound acting as fuel is glucose.
In relation to free oxygen, organisms are divided into three groups.
Aircomes (bonded aerobes) are organisms capable of living only in an oxygen medium (animals, plants, some bacteria and mushrooms).
Anaeroba (bonde anaerobes) - organisms unable to live in an oxygen medium (some bacteria).
Optional forms (optional anaerobes) are organisms capable of living both in the presence of oxygen, and without it (some bacteria and mushrooms).
In obligate aerobs and optional anaerobes in the presence of oxygen, catabolism flows into three stages: preparatory, oxygen and oxygen. As a result, organic substances disintegrate to inorganic compounds. In bonde anaerobes and optional anaerobov, with a lack of oxygen, catabolism flows in the first two stages: preparatory and oxygenous. As a result, intermediate organic compounds are formed even rich energy.
Catabolism steps:
1. The first stage is the preparatory - lies in the enzymatic splitting of complex organic compounds to simpler. Proteins are split to amino acids, fats to glycerol and fatty acids, polysaccharides to monosaccharides, nucleic acids to nucleotides. In multicellular organisms, this occurs in the gastrointestinal tract, in unicellular - in lysosomes under the action of hydrolytic enzymes. Eased energy dissipates in the form of heat. The resulting organic compounds are either subjected to further oxidation, or used by the cell for the synthesis of own organic compounds.
2. The second stage is incomplete oxidation (oxidation) - lies in the further splitting of organic substances, is carried out in the cytoplasm of the cell without the participation of oxygen.
Cystic, incomplete oxidation of glucose is called Glycoliz. As a result of the glycolysis of one glucose molecule, two pivine acid molecules (PVC, PIRUVAT) CH3COCOOH, ATP and WATER, as well as hydrogen atoms, which are binding to a carrier molecule over + and are reserved as NADN.
The total glycolysis formula has the following form:
C6H12O6 + 2 H3PO4 + 2 ADF + 2 OUM + -\u003e 2 C3N4O3 + 2 H2O + 2 ATP + 2 NADN.
In the absence of oxygen in the oxygen medium, glycolysis products (PVC and NADN) are processed either to ethyl alcohol - alcohol fermentation (in the cells of yeast and plants with a lack of oxygen)
CH3COCOOH -\u003e CO2 + CH3ON
CH3ON + 2 NADN -\u003e C2N5on + 2 above +,
Either in lactic acid - lactic acid fermentation (in animal cells with a lack of oxygen)
CH3COCOOH + 2 NADHN C3N6O3 + 2 Over +.
If there is an oxygen in the oxygen medium, glycolysis products undergo further splitting to final products.
3. The second stage is complete oxidation (breathing) - consists in oxidizing the PVC to carbon dioxide and water, is carried out in mitochondria, with the obligatory participation of oxygen.
It consists of three stages:
A) the formation of acetylcoenzyme A;
B) oxidation of acetylcoenzyme A in the Krebs cycle;
C) oxidative phosphorylation in the electron transport chain.
A. At the first stage, PVC is transferred from cytoplasm in mitochondria, where interacts with the enzymes of the matrix and forms: 1) carbon dioxide, which is derived from the cell; 2) hydrogen atoms that are delivered to molecules-carriers to the inner membrane of mitochondria; 3) Acetylcooferment A (Acetyl-CoA).
B. In the second stage, acetylcoenzyme oxidation occurs in the Krebs cycle. Krebs cycle (cycle of tricarboxylic acids, citric acid cycle) is a circuit of consecutive reactions, during which from one acetyl-cola molecule is formed: 1) two carbon dioxide molecules, 2) ATP molecule and 3) four pairs of hydrogen atoms transmitted to molecules - Personnel - Over and Fad.
Thus, as a result of glycolysis and the Krebs cycle, the glucose molecule is split to CO2, and the energy released is spent on the synthesis of 4atf and accumulates in 10 Natn and 4fadt2.
B. In the third stage, hydrogen atoms with NAPN and FadTn2 are oxidized by molecular oxygen O2 with water formation. One breath is capable of forming 3 ATPs, and one FadTn2 - 2 ATP. Thus, the energy released at the same time is in the form of another 34 ATP. The formation of ATP in mitochondria with oxygen participation is the oxidative phosphorylation.
Thus, the total glucose splitting equation in the process of cellular respiration is as follows:
C6H12O6 + 6 O2 + 38 H3PO4 + 38 ADF -\u003e 6 CO2 + 44 H2O + 38 ATP.
Thus, during glycolysis, 2 ATP molecules are formed during cellular respiration - another 36 ATP, in general, with full oxidation of glucose - 38 ATPs.
4.5. Plastic exchange
4.5.1. Photosynthesis
Photosynthesis - synthesis of organic compounds from inorganic due to the energy of light. Total photosynthesis equation:
6 C2 + 6 H2O -\u003e C6H12O6 + 6 O2.
Photosynthesis proceeds with the participation of photosynthetic pigments with a unique property of conversion of solar light into the chemical energy in the form of ATP. The most important is the Pigment Chlorophyll.
The process of photosynthesis consists of two phases: light and dark.
1. The light phase of photosynthesis proceeds only on the light in the tylacoid membrane of the grain. It includes: absorption by chlorophyll of light quanta, photoliz of water and the formation of ATP molecule.
Under the action of the light quantum (HV), chlorophyll loses electrons, moving to the excited state:
HV
Chl -\u003e Chl * + E-.
These electrons are transmitted by carriers to the outer, that is, the Tylacoid membrane surface facing the matrix, where they accumulate.
At the same time inside the thylacoids, the water is happening, that is, its decomposition under the action of light
HV
2 H2O -\u003e O2 +4 H + + 4 E-.
The resulting electrons are transmitted by carriers to chlorophyll molecules and restore them. Chlorophyll molecules are returned to a stable state.
The hydrogen protons formed during the photolisis of water are accumulated inside the thylacoid, creating a H + -rerevoire. As a result, the inner surface of the thylacoid membrane is charged positively (due to H +), and the outer-negative (due to E-). As they accumulate on both sides of the membrane oppositely charged particles, the potential difference increases. When the critical amount of potential difference is reached, the power of the electric field begins to push protons through the ATP-synthetase channel. The energy released is used to phosphorylation ADP molecules. The formation of ATP in the process of photosynthesis under the action of light energy is called photo phosphorylation.
Hydrogen ions, found ourselves on the outer surface of the thylacoid membrane, are found there with electrons and form atomic hydrogen, which binds to a molecule-carrier of hydrogen NADF (nicotinyndaenindinucleotidphosphate):
2 H + + 4E- + Nadf + -\u003e Nadfn2.
Thus, three processes occur during the light phase of photosynthesis: oxygen formation due to water decomposition, ATP synthesis and the formation of hydrogen atoms in the form of NADFN2. Oxygen diffuses into the atmosphere, and ATP and NADFTN2 are involved in the dark phase processes. 2. The small phase of photosynthesis proceeds in the chloroplast matrix both in the light and in the dark and is a number of consecutive CO2 transformations coming from the air in the Calvin cycle. The reactions of the dark phase due to the energy of ATP. In the Calvin CO2 cycle, it is binding to hydrogen from Nadfn2 to form glucose.
In the process of photosynthesis, in addition to monosaccharides (glucose, etc.), monomers of other organic compounds - amino acids, glycerin and fatty acids are synthesized.
4.5.2. Chemosynthesis
Chemosynthesis (chemoavtotrophy) is the process of synthesizing organic compounds from inorganic (CO2, etc.) due to the chemical energy of oxidation of inorganic substances (sulfur, hydrogen sulfide, iron, ammonia, nitrite, etc.).
Only chemosynthetic bacteria are capable of chemosynthesis: nitrifying, hydrogen, ferruplane, sulfifying, and others. They oxidize nitrogen compounds, iron, sulfur and other elements. All chemosynthetics are bonded aerobs, as the air is used.
The energy released during oxidation reactions is reserves with bacteria in the form of ATP molecules and is used for the synthesis of organic compounds, which proceeds similarly to the reactions of the dark phase of photosynthesis.
4.5.3. Biosynthesis protein
Genetic information is practically stored in all organisms in the form of a certain sequence of DNA nucleotides (or RNA in RNA-containing viruses). Prokaryotes and many viruses contain genetic information in the form of one DNA molecule. All its sections are coding macromolecules. In eukaryotic cells, the genetic material is distributed in several DNA molecules organized in chromosome.
The gene is a DNA molecule site (less raging RNA) encoding the synthesis of one macromolecule: MRNA (polypeptide), RRNA or TRNA. The chromosome portion, where the gene is located locus. The combination of genes of the cell nucleus is a genotype, a set of genes of the haploid set of chromosome - genome, a set of non-core DNA genes (mitochondria, plastids, cytoplasm) - plasmon.
The implementation of information recorded in genes, through the synthesis of proteins is called expression (manifestation) of genes. Genetic information is stored as a specific DNA nucleotide sequence, and is implemented as a sequence of amino acids in protein. Intermediaries, network carriers are RNA. That is, the implementation of genetic information is as follows:
DNA -\u003e RNA -\u003e Protein
This process is carried out in two stages:
1) transcription;
2) Broadcast.
Transcription - RNA synthesis using DNA as a matrix. As a result, mRNA occurs. The transcription process requires high energy costs in the form of ATP and is carried out by the RNA polymerase enzyme.
At the same time, not the entire DNA molecule is transcribed, but only its separate segments. Such a segment (transcripton) begins the promoter - the DNA region where the RNA polymerase is attached and where the transcription begins, and the terminator - the DNA portion containing the transcription signal. Transcripton is gene from the point of view of molecular biology.
Transcription, as well as replication, is based on the ability of nuclear nucleotide bases to complementary binding. At the time of transcription, the DNA double circuit is broken and the synthesis of RNA is carried out on one DNA chain.
In the process of broadcast, the DNA nucleotide sequence is rewritten to the synthesized mRNA molecule, which acts as a matrix in the process of protein biosynthesis.
The transmission is the synthesis of the polypeptide chain using mRNA as a matrix.
All three types of RNA are involved in the broadcast: mRNA is an information matrix; TRNA delivers amino acids and recognize codons; RRNA, together with proteins, form ribosomes, which hold mRNA, TRNA and protein and carry out the synthesis of the polypeptide chain.
MRNA is broadcast not one, but at the same time several (up to 80) ribosomes. Such groups of ribosomes are called polisms. On the inclusion of one amino acid into the polypeptide chain, the energy of 4 ATPs is necessary.
DNA code. Information about the structure of proteins "is written" into DNA in the form of a sequence of nucleotides. In the transcription process, it corresponds to the synthesized mRNA molecule, which acts as a matrix in the protein biosynthesis process. A specific combination of DNA nucleotides, and, consequently, mRNA corresponds to a certain amino acid in the protein polypeptide chain. This compliance is called genetic code. One amino acid is determined by 3 nucleotides combined into a triplet (codon). Since there are 4 types of nucleotides, combining 3 in a triplet, they give 43 \u003d 64 of the variant of the triplets (while only 20 amino acids are encoded). Of these, 3 are "stop codons", stopping the broadcast, the remaining 61 are coding. Different amino acids are encoded by different types of triplets: from 1 to 6.
Properties of the genetic code:
1. Kod triplet. One amino acid is encoded by three nucleotides (triplet) in a nucleic acid molecule.
2. Code universal. All living organisms from viruses to humans use a single genetic code.
3. Code is unequivocal (specific). The codon corresponds to one single amino acid.
4. Code is excessive. One amino acid is encoded with more than one triplet.
5. Code does not overlap. One nucleotide cannot be part of several codons in a nucleic acid chain.
Stages of protein synthesis:
1. The variant sub-partition of ribosomes is connected to the initiator of Met-TRNA, and then with mRNA, after which the formation of a whole ribosome consisting of a small and large subcontitz occurs.
2. Rybosoma moves along mRNA, which is accompanied by repeated repeating cycle of the addition of another amino acid to the growing polypeptide chain.
3. The robosome reaches one of the three Stop Codons of MRNA, the polypeptide chain is released and separated from the ribosome. Ribosomal sub-disks are dissociated, separated from mRNA and can take part in the synthesis of the next polypeptide chain.
Reactions of matrix synthesis. Reactions of matrix synthesis include: DNA self-esteem, mRNA, TRNA and RRNA formation on DNA molecule, protein biosynthesis on mRNA. All these reactions combine that the DNA molecule in one case or molecule of mRNA in the other act as a matrix, on which the formation of the same molecules occurs. The reactions of matrix synthesis are the basis of the ability of living organisms to reproduce their likes.
Http://sfedu.ru/lib1/chem/2010101/m2_a_020101.htm
your ideas in life that
2) in modern youth simply there is no time. The program is so big that
3) Society does not know what school board is like (there is a comparison) ........, why .........
1. When the temperature is raised above 20-25 degrees Celsius, the speed of photosynthesis decreases, because: a) begins to evaporate water intensivelyb) Ustian closes, which prevents carbon dioxide penetration
c) the denaturation of enzymes, catalyzing photosynthesis reactions begins
d) the excitation of electrons in chlorophyll molecules is reduced
2. Oxidation processes occur in cellular organelles:
a) in ribosomes
b) in mitochondria
c) in the endoplasmic network
d) in mitochondria and chloroplasts
3. The first and second phase of splitting high molecular compounds in the cell occurs in:
a) cytoplasm
b) Mitochondria
c) lysosomes
d) Golgi Complex
4. The main finite products of the Krebs cycle are:
a) carbon dioxide and oxygen
b) carbon dioxide and phad * n2
c) SHAVELEVOUSUS acid and pyruvat d) oxaluaceous acid, over * H2 and ADP
e) SHAVELEUCUSUSIC Acid, over * H2 and ADP
e) SHAVELEUCUSUSIC Acid, over * H2, FAD * H2 and ATP
5. The finite products of alcohol fermentation are:
a) alcohol, lactic acid, ATP, carbon dioxide
b) water and carbon dioxide
c) lactic acid
d) alcohol, water, carbon dioxide and ATP
6. The similarity of the fermentation process in bacterial cells and in mammalian muscles in oxygen starvation conditions is to form:
a) large amount of carbon dioxide
b) alcohol
c) over + out of * n + n +
d) acetyl-coa d) of lactic acid
7. Fat, which is filled with a camel hump, is primarily not a source of energy, but a source of water. Obtaining water from fat provides a metabolic process:
a) oxidation
b) the conversion of fat into carbohydrates
c) decomposition of fat for water, fatty carboxylic acids and glycerin
8. Fats are the most efficient sources of energy in the cell, because:
a) their molecules contain many carbon and hydrogen atoms
b) these are low molecular weight connections
c) their molecules do not contain double connections
d) their molecules hold little oxygen atoms
Who knows what to write to the answers9. Endoplasmic network is
a) cell internal skeleton
b) the membrane and tubule system where synthesis and transportation of substances occurs
c) Membrane system and tubules are similar to an excretory system of organisms
10. Most live cells are characteristic:
a) the ability to form genital cells
b) ability to carry out a nervous impulse
c) ability to shrink
d) the ability to exchange substances
11. Water-based life, because:
a) may be in three aggregate states
b) in the cells of the embryo, it is greater than 90%
c) it is a solvent providing both the influx of substances into the cell and the removal of the exchange products from it
d) cools the surface during evaporation
12. The chain is a sequence of Tagggzzhatg nucleotide. Determine the sequence of nucleotides on the IRNA.
13. The essence of cell theory is more accurate:
a) all plant organisms consist of cells
b) all living organisms consist of cells
c) everything as prokaryotes and eukaryotes consist of cells
d) cells of all organisms are the same in structure
14. Transcription is carried out in the process:
a) translation of information from DNA on INK
b) DNA replication
c) translation of RNA information into the sequence of amino acids in protein
d) DNA reparations
15. In animal cells, the spare carbohydrate are:
a) cellulose
b) Stachmal
c) Murein
d) glycogen
but. Loss of woolen cover by elephants b. Elimination of horse limbs
at. The appearance of eggs reptiles and their development on land
3. Which directions of evolution leads to serious rearrangements of the body and the emergence of new taxa?
but. Transformation of cactus leaves in spines b. The emergence of heatchard
at. Loss of digestive organs in flat worms
4. Different types of Darwinian reels arose by:
but. Aromorphosis b. degeneration in. idioadaption
5. Algae belong to the lower, and the MAYs to the highest plants, because:
but. MAs multiply disputes, and algae is not b. Mukhov has chlorophyll, and there is no algae
at. Movh has organs that have improved their organization compared to algae
G. The division into the lower and higher plants is conditional, because the MAY, and algae are at one level of development.
6. Which listed is related to aromorphosis, idioadaption, degeneration?
but. Cellic lungs in reptile b. Primary brain cortex
at. Naked tail in beauty G. No limbs at the snake
d. no roots for reary
e. The emergence of the partition in the ventricle of the heart in reptile
g. Milk glands in mammals. LAST EDUCATION
and. Lack of blood system near chain
k. Lack of sweat glands in dogs
7. As a result of chlorophyll, organisms were transferred:
but. to autotrophic nutrition b. To heterotrophic nutrition
at. To the mixed type of power 8. A variety of devices is explained:
but. Only the influence of environmental conditions on the body
b. interaction of genotype and environmental conditions. Only features of the genotype
8. The biological progress of a group of organisms is achieved by ways:
A. Aromorphosis b. idioadaptation in. General degeneration
G. A + B d. A + B + in
9. A view that is in a state of biological progress is characterized by:
A. Expectation of the organization level b. Reduced organization level
V.Reschilation of Area, an increase in the number, the disintegration of the form on subspecies
G. Reducing the number and reduction of range
10. In the state of biological progress is the view:
A. Zubr b. Ginkgo in. Black Crane G. House Sparrow
11. Which of the types of organisms listed below are in a state of biological regression?
A.elodea Canadian B.Coladskiy Zhuk V. Usuri Tiger G. Rat Gray
13. The path of evolution, in which the similarities arise between organisms of various systematic groups living in similar conditions, is called:
A.Gradation b. Divergence V. Korvergenia G. Pollhelism
14. From the files below, organs are not homologous:
A. Fuel equilibrium authorities (buzzing), ensuring their steady flight - insect wings
B
15. From the listed pairs of organisms, an example of convergence can be:
A.Boy and brown bear b. Summer and Polar Wolf
B. Ordinary Fox and Lescent Mr Mole and Earthowing
