RNA molecules are polymers, the monomers of which are ribonucleotides formed by residues of three substances: a five-carbon sugar - ribose; one of the nitrogenous bases - from purine - adenine or guanine, from pyrimidines - uracil or cytosine; residue of phosphoric acid.

"2. Card on the board"

Write the question numbers on the board

against them - short answers.

……………………….

Where is DNA found in eukaryotic cells?

What is the size of DNA?

What purine bases are included in the DNA molecule?

A DNA fragment contains 30,000 nucleotides. DNA duplication occurs, how many free nucleotides will this require?

How are DNA nucleotides connected into one chain?

A DNA fragment contains 30,000 A-nucleotides. DNA duplication occurs, how many A- and T-nucleotides are required for this?

A DNA fragment contains 30,000 A-nucleotides and 40,000 C-nucleotides. How many T- and G-nucleotides are there in this fragment?

What are the functions of DNA in a cell?

How are the nucleotide chains arranged in a DNA molecule?

Write down your answers and sit down.

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"4. Codogram. RNA, ATP"

Topic: RNA, ATP.

1. Characteristics of RNA, ATP.

Structure : polymer, one polynucleotide chain.

An RNA nucleotide consists of residues of three substances:

Instead of thymine - uracil. Uridyl nucleotide.

Hydrogen bonds are formed between complementary nucleotides, and specific conformations of RNA molecules are formed.

Functions : participation in protein synthesis.

Kinds : mRNA (mRNA), tRNA, rRNA.

Messenger RNA(around 5%). Transfer information about the protein from the nucleus to the cytoplasm. Length up to 30,000 nucleotides.

Ribosomal RNA(about 85%) are synthesized in the nucleus in the region of the nucleolus and are part of the ribosomes. 3,000 – 5,000 nucleotides.

Transfer RNAs(about 10%). Transport amino acids to ribosomes. More than 30 species, 76 - 85 nucleotides.

End products of biosynthesis?

A

TF?

Hormones?

Vitamins?

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"Biopolymers. RNA, ATP"

Biopolymers. RNA, ATP

1. Characteristics of RNA.

RNA molecules are polymers, the monomers of which are ribonucleotides formed by residues of three substances: a five-carbon sugar - ribose; one of the nitrogenous bases - from the purine bases - adenine or guanine, from pyrimidine - uracil or cytosine; residue of phosphoric acid.

An RNA molecule is an unbranched polynucleotide with a tertiary structure. The joining of nucleotides into one chain occurs as a result of a condensation reaction between the phosphoric acid residue of one nucleotide and the 3" ribose carbon of the second nucleotide.

Unlike DNA, RNA is formed not by two, but one polynucleotide chain. However, its nucleotides (adenyl, uridyl, thymidyl and cytidyl) are also capable of forming hydrogen bonds with each other, but these are intra- rather than inter-chain compounds of complementary nucleotides. Two hydrogen bonds are formed between A- and U-nucleotides, and three hydrogen bonds are formed between G- and C-nucleotides. RNA chains are much shorter than DNA chains.

Information about the structure of an RNA molecule is contained in DNA molecules. The sequence of nucleotides in RNA is complementary to the codogenic strand of DNA, but the adenyl nucleotide of DNA is complementary to the uridyl nucleotide of RNA. While the DNA content in a cell is relatively constant, the RNA content fluctuates greatly. The largest amount of RNA in cells is observed during protein synthesis.

There are three main classes of nucleic acids: messenger RNA - mRNA (mRNA), transfer RNA - tRNA, ribosomal RNA - rRNA.

Messenger RNAs. The most diverse class in terms of size and stability. All of them are carriers of genetic information from the nucleus to the cytoplasm. Messenger RNAs serve as a template for the synthesis of protein molecules, because determine the amino acid sequence of the primary structure of the protein molecule. mRNA accounts for up to 5% of the total RNA content in the cell.

Transfer RNAs. Transfer RNA molecules usually contain 75-86 nucleotides. The molecular weight of tRNA molecules is  25,000. tRNA molecules play the role of intermediaries in protein biosynthesis - they deliver amino acids to the site of protein synthesis, to ribosomes. The cell contains more than 30 types of tRNA. Each type of tRNA has a unique nucleotide sequence. However, all molecules have several intramolecular complementary regions, due to the presence of which all tRNAs have a tertiary structure resembling a clover leaf in shape.

Ribosomal RNAs. Ribosomal RNA (rRNA) accounts for 80-85% of the total RNA content in the cell. Ribosomal RNA consists of 3-5 thousand nucleotides. In complex with ribosomal proteins, rRNA forms ribosomes - organelles on which protein synthesis occurs. The main significance of rRNA is that it ensures the initial binding of mRNA and the ribosome and forms the active center of the ribosome, in which the formation of peptide bonds between amino acids occurs during the synthesis of the polypeptide chain.

2. Characteristics of ATP.

In addition to proteins, fats and carbohydrates, a large number of other organic compounds are synthesized in the cell, which can be divided into intermediate And final. Most often, the production of a certain substance is associated with the operation of a catalytic conveyor (a large number of enzymes), and is associated with the formation of intermediate reaction products that are acted upon by the next enzyme. The final organic compounds perform independent functions in the cell or serve as monomers in the synthesis of polymers. The final substances include amino acids, glucose, nucleotides, ATP, hormones, vitamins.

Adenosine triphosphoric acid (ATP) is a universal source and main energy accumulator in living cells. ATP is found in all plant and animal cells. The amount of ATP varies and averages 0.04% (per cell wet weight). The largest amount of ATP (0.2-0.5%) is contained in skeletal muscles.

ATP is a nucleotide consisting of a nitrogenous base (adenine), a monosaccharide (ribose) and three phosphoric acid residues. Since ATP contains not one, but three phosphoric acid residues, it belongs to ribonucleoside triphosphates.

Most of the work that happens in cells uses the energy of ATP hydrolysis. In this case, upon cleavage of the terminal phosphoric acid residue, ATP is converted into ADP ( adenosine diphosphorus acid), upon elimination of the second phosphoric acid residue - into AMP ( adenosine monophosphorus acid). The free energy yield upon elimination of both the terminal and second residues of phosphoric acid is 30.6 kJ. The elimination of the third phosphate group is accompanied by the release of only 13.8 kJ. The bonds between the terminal and second, second and first residues of phosphoric acid are called high-energy (high-energy).

ATP reserves are constantly replenished. In the cells of all organisms, ATP synthesis occurs in the process of phosphorylation, i.e. addition of phosphoric acid to ADP. Phosphorylation occurs with varying intensity in mitochondria, during glycolysis in the cytoplasm, and during photosynthesis in chloroplasts.

The final organic molecules are also vitamins And hormones. Play a major role in the life of multicellular organisms vitamins. Vitamins are considered to be organic compounds that a given organism cannot synthesize (or synthesizes in insufficient quantities) and must receive them with food. Vitamins combine with proteins to form complex enzymes. If there is a lack of any vitamin in food, the enzyme cannot be formed and one or another vitamin deficiency develops. For example, a lack of vitamin C leads to scurvy, a lack of vitamin B 12 leads to anemia, a disruption of the normal formation of red blood cells.

Hormones are regulators, affecting the functioning of individual organs and the entire organism as a whole. They can be of a protein nature (hormones of the pituitary gland, pancreas), they can be lipids (sex hormones), they can be derivatives of amino acids (thyroxine). Hormones are produced by both animals and plants.

Questions for testing:

During the test you will be asked 10 questions that need to be answered. in one complete sentence .

Or testing on a computer, a test task of 15 questions.

Carbohydrates- These are organic compounds that include carbon, hydrogen and oxygen. Carbohydrates are divided into mono-, di- and polysaccharides.

Monosaccharides are simple sugars consisting of 3 or more C atoms. Monosaccharides: glucose, ribose and deoxyribose. Do not hydrolyze, may crystallize, soluble in water, have a sweet taste

Polysaccharides are formed as a result of the polymerization of monosaccharides. At the same time, they lose their ability to crystallize and their sweet taste. Example - starch, glycogen, cellulose.

1. Energy is the main source of energy in the cell (1 gram = 17.6 kJ)

2. structural - part of the membranes of plant cells (cellulose) and animal cells

3. source for the synthesis of other compounds

4. storage (glycogen - in animal cells, starch - in plant cells)

5. connecting

Lipids- complex compounds of glycerol and fatty acids. Insoluble in water, only in organic solvents. There are simple and complex lipids.

Functions of lipids:

1. structural - the basis for all cell membranes

2. energy (1 g = 37.6 kJ)

3. storage

4. thermal insulation

5. source of intracellular water

ATP - a single universal energy-intensive substance in the cells of plants, animals and microorganisms. With the help of ATP, energy is accumulated and transported in the cell. ATP consists of the nitrogenous base adeine, the carbohydrate ribose, and three phosphoric acid residues. Phosphate groups are connected to each other using high-energy bonds. The functions of ATP are energy transfer.

Squirrels are the predominant substance in all living organisms. Protein is a polymer whose monomer is amino acids (20). Amino acids are connected in a protein molecule using peptide bonds formed between the amino group of one amino acid and the carboxyl group of another. Each cell has a unique set of proteins.

There are several levels of organization of the protein molecule. Primary structure - sequence of amino acids connected by a peptide bond. This structure determines the specificity of the protein. In secondary The structure of the molecule has the shape of a spiral, its stability is ensured by hydrogen bonds. Tertiary the structure is formed as a result of the transformation of the spiral into a three-dimensional spherical shape - a globule. Quaternary occurs when several protein molecules combine into a single complex. The functional activity of proteins manifests itself in the 2,3, or 3 structure.

The structure of proteins changes under the influence of various chemicals (acid, alkali, alcohol and others) and physical factors (high and low t radiation), enzymes. If these changes preserve the primary structure, the process is reversible and is called denaturation. The destruction of the primary structure is called coagulation(irreversible process of protein destruction)

Functions of proteins

1. structural

2. catalytic

3. contractile (actin and myosin proteins in muscle fibers)

4. transport (hemoglobin)

5. regulatory (insulin)

6. signal

7. protective

8. energy (1 g=17.2 kJ)

Types of nucleic acids. Nucleic acids- phosphorus-containing biopolymers of living organisms, providing storage and transmission of hereditary information. They were discovered in 1869 by the Swiss biochemist F. Miescher in the nuclei of leukocytes and salmon sperm. Subsequently, nucleic acids were found in all plant and animal cells, viruses, bacteria and fungi.

There are two types of nucleic acids in nature - deoxyribonucleic acid (DNA) And ribonucleic acid (RNA). The difference in names is explained by the fact that the DNA molecule contains the five-carbon sugar deoxyribose, and the RNA molecule contains ribose.

DNA is found primarily in the chromosomes of the cell nucleus (99% of all cell DNA), as well as in mitochondria and chloroplasts. RNA is part of ribosomes; RNA molecules are also contained in the cytoplasm, matrix of plastids and mitochondria.

Nucleotides- structural components of nucleic acids. Nucleic acids are biopolymers whose monomers are nucleotides.

Nucleotides- complex substances. Each nucleotide contains a nitrogenous base, a five-carbon sugar (ribose or deoxyribose) and a phosphoric acid residue.

There are five main nitrogenous bases: adenine, guanine, uracil, thymine and cytosine.

DNA. A DNA molecule consists of two polynucleotide chains, spirally twisted relative to each other.

The nucleotides of a DNA molecule include four types of nitrogenous bases: adenine, guanine, thymine and cytocin. In a polynucleotide chain, neighboring nucleotides are connected to each other by covalent bonds.

The polynucleotide chain of DNA is twisted in the form of a spiral like a spiral staircase and connected to another, complementary chain, using hydrogen bonds formed between adenine and thymine (two bonds), as well as guanine and cytosine (three bonds). Nucleotides A and T, G and C are called complementary.

As a result, in any organism the number of adenyl nucleotides is equal to the number of thymidyl nucleotides, and the number of guanyl nucleotides is equal to the number of cytidyl nucleotides. Thanks to this property, the sequence of nucleotides in one chain determines their sequence in the other. This ability to selectively combine nucleotides is called complementarity, and this property underlies the formation of new DNA molecules based on the original molecule (replication, i.e. doubling).

When conditions change, DNA, like proteins, can undergo denaturation, which is called melting. With a gradual return to normal conditions, the DNA renatures.

Function of DNA is the storage, transmission and reproduction of genetic information over generations. The DNA of any cell encodes information about all the proteins of a given organism, about which proteins, in what sequence and in what quantities will be synthesized. The sequence of amino acids in proteins is written in DNA by the so-called genetic (triplet) code.

Main property DNA is its ability to replicate.

Replication - This is a process of self-duplication of DNA molecules that occurs under the control of enzymes. Replication occurs before each nuclear division. It begins with the DNA helix temporarily unwinding under the action of the enzyme DNA polymerase. On each of the chains formed after the rupture of hydrogen bonds, a daughter DNA strand is synthesized according to the principle of complementarity. The material for synthesis are free nucleotides that are present in the nucleus

Thus, each polynucleotide chain plays a role matrices for a new complementary chain (therefore, the process of doubling DNA molecules refers to reactions matrix synthesis). The result is two DNA molecules, each of which has one chain remaining from the parent molecule (half), and the other newly synthesized. Moreover, one new chain is synthesized continuous, and the second - first in the form of short fragments, which are then stitched into a long chain a special enzyme - DNA ligase.As a result of replication, two new DNA molecules are an exact copy of the original molecule.

The biological meaning of replication lies in the accurate transfer of hereditary information from the mother cell to the daughter cells, which occurs during the division of somatic cells.

RNA. The structure of RNA molecules is in many ways similar to the structure of DNA molecules. However, there are a number of significant differences. In the RNA molecule, the nucleotides contain ribose instead of deoxyribose, and uridyl nucleotide (U) instead of thymidyl nucleotide (T). The main difference from DNA is that the RNA molecule is a single strand. However, its nucleotides are capable of forming hydrogen bonds with each other (for example, in tRNA, rRNA molecules), but in this case we are talking about an intrachain connection of complementary nucleotides. RNA chains are much shorter than DNA.

There are several types of RNA in a cell, which differ in molecular size, structure, location in the cell and functions:

1. Messenger RNA (mRNA) - transfers genetic information from DNA to ribosomes

2. Ribosomal RNA (rRNA) - part of ribosomes

3. 3. Transfer RNA (tRNA) - carries amino acids to ribosomes during protein synthesis



Cytology

Basic principles of cell theory. A cell is a structural and functional unit of living things page 1

Organic substances of the cell: lipids, ATP, biopolymers (carbohydrates, proteins, nucleic acids) and their role in the cell. p.5

Enzymes, their role in the process of life p. 7

Features of the structure of prokaryotic and eukaryotic cells p. 9

Main structural components of a cell page 11

Surface apparatus of the cell page 12

Transport of molecules across membranes p. 14

Receptor function and its mechanism p. 18

Structure and functions of cell contacts page 19

Locomotor and individualizing functions of PAK p. 20

Organelles of general importance. Endoplasmic reticulum page 21

Golgi complex page 23

Lysosomes page 24

Peroxisomes page 26

Mitochondria page 26

Ribosomes p.27

Plastids p.28

Cellular center page 28

Organelles of special significance p. 29

Cell nucleus. Structure and functions page 29

Metabolism and energy conversion in the cell p. 32

Chemosynthesis page 36

1. Basic principles of cell theory. A cell is a structural and functional unit of living things.

Cytology - science of cells. Cytology studies the structure and chemical composition of cells, the functions of intracellular structures, the functions of cells in the body of animals and plants, the reproduction and development of cells. Of the 5 kingdoms of the organic world, only the kingdom of Viruses, represented by living forms, do not have a cellular structure. The remaining 4 kingdoms have a cellular structure: the kingdom of Bacteria unites prokaryotes - prenuclear forms. Nuclear forms are eukaryotes, these include the kingdoms Fungi, Plants, and Animals. Basic principles of cell theory: Cell - functional and structural unit of living things. Cell - the elementary system is the basis of the structure and functioning of the organism. The discovery of the cell is associated with the discovery of the microscope: 1665 – Hooke invented a microscope and on a section of a cork he saw cells, which he called cells. 1674 – A. Levinguk was the first to discover single-celled organisms in water. Early 19th century – J. Purkinje called the substance that fills the cell protoplasm. 1831 – Brown discovered the nucleus. 1838-1839 – Schwann formulated the main provisions of the cell theory. Basic principles of cell theory:

1. Cell - the main structural unit of all organisms.

2. Cell formation process is determined by the growth, development and differentiation of plant and animal cells.

1858 – Virchow’s work “Cellular Pathology” was published, in which he linked pathological changes in the body with changes in the structure of cells, laying the foundation for pathology - the beginning of theoretical and practical medicine. Late 19th century – Baer discovered the egg, showing that all living organisms originate from a single cell (zygote). The complex structure of the cell was discovered, organelles were described, and mitosis was studied. Early 20th century – The significance of cellular structures and the transmission of hereditary properties became clear. Modern cell theory includes the following provisions:

Cell - the basic unit of structure and development of all living organisms, the smallest unit of living things.

Cells All unicellular and multicellular organisms are similar in their structure, chemical composition, basic manifestations of life activity and metabolism.

Cell Reproduction occurs by division, and each new cell is formed by dividing the original (mother) cell.

In complex multicellular organisms cells are specialized according to the functions they perform and form tissues. Organs are made up of tissues, which are interconnected and subordinate to nervous and humoral regulatory systems.

Cell - is an open system for all living organisms, characterized by flows of matter, energy and information associated with metabolism (assimilation and dissimilation). Self-updating carried out as a result of metabolism. Self-regulation carried out at the level of metabolic processes according to the feedback principle. Self-reproduction The cell is provided during its reproduction based on the flow of matter, energy and information. The cell and cellular structure provides:

Thanks to the large surface, favorable conditions for metabolism.

The best storage and transmission of hereditary information.

The ability of organisms to store and transfer energy and convert it into work.

Gradual replacement of the entire organism (multicellular) of dying parts without replacing the entire organism.

In a multicellular organism, cell specialization provides broad adaptability of the organism and its evolutionary capabilities.

Cells have structural similarity, i.e. similarity at different levels: atomic, molecular, supramolecular, etc. Cells have functional similarity, unity of chemical metabolic processes.