Lysosomes. Mitochondria. Plastids
1. What is the structure and functions ATP?
2. What types of plastids do you know?
When various nutrients enter a cell through phagocytosis or pinocytosis, they must be digested. Wherein squirrels must be broken down to individual amino acids, polysaccharides - to molecules of glucose or fructose, lipids- to glycerol and fatty acids. For intracellular digestion to be possible, the phagocytic or pinocytic vesicle must fuse with the lysosome (Fig. 25). A lysosome is a small bubble, only 0.5-1.0 microns in diameter, containing a large set of enzymes capable of destroying nutrients. One lysosome can contain 30-50 different enzymes.
Catabolic system of the cell
The catabolic system of the cell includes: lysosomes, microbodies (peroxisomes, glyoxysomes) and mitochondria.
5.1. Primary lysosomes are formed in the Golgi complex. They are small (0.2-1 microns) round bodies, covered with an elementary membrane, and containing up to 30 different hydrolytic enzymes. When endosomes enter the cytoplasm, they merge
Rice . Structure of a lysosome
with primary lysosomes, the enzymes of which are activated and form phagosomes (secondary lysosomes), in which complex organic compounds are broken down into simpler ones (proteins into amino acids, etc.).
Rice. The structure of mitochondria.
5.2. Mitochondria have two membranes - outer and inner. The inner membrane forms invaginations into the mitochondrial cavity, which are called cristae. On the cristae of mitochondria there are spherical bodies on legs - ATP-somes. Between the cristae there is a matrix that contains an autonomous biosynthesis system
Rice. ATP-somes on mitochondrial cristae
protein (circular DNA molecules and ribosomes). The main functions of mitochondria: synthesis of ATP, specific proteins and steroid hormones.
5.3. Energy exchange, or dissimilation, includes three stages:
I – preparatory;
II - oxygen-free (anaerobic, glycolysis);
III – oxygen (aerobic).
The primary source of energy on Earth is the Sun. Its light energy is accumulated by green plants during photosynthesis in the chemical bonds of complex organic compounds. Heterotrophic organisms are able to absorb only this type of energy.
The preparatory stage takes place in the digestive system of organisms and in the lysosomes of cells and consists in the fact that complex organic compounds are broken down into simpler ones: proteins into amino acids, polysaccharides into monosaccharides, fats into glycerol and fatty acids. The released energy is dissipated as heat.
The anaerobic stage occurs in the cytoplasm of cells. During glycolysis, monosaccharides, amino acids and fatty acids are broken down into pyruvic or lactic acids. The anaerobic breakdown of 1 molecule of glucose produces 2 molecules of ATP. 10 cytoplasmic enzymes are involved in glycolysis.
The aerobic stage of energy metabolism occurs in mitochondria. Pyruvic acid formed during glycolysis combines with coenzyme A and in this form (Acetyl CoA) enters the mitochondrial matrix. Mitochondria contain 3 groups of enzymes: the Krebs cycle (matrix), tissue respiration (cristae) and oxidative phosphorylation (ATP-somes). Acetyl Co A enters the Krebs cycle, whose enzymes (dehydrogenases) gradually remove hydrogen atoms from its molecule, ultimately forming carbon dioxide. Carbon dioxide is released from the mitochondria. Hydrogen atoms are split into protons and electrons, which enter the system of tissue respiration enzymes, where, during the transition in the electron transport chain (electron cascade), they accumulate on opposite sides of the membranes (protons on the outer surface, and electrons on the inner surface). When the critical potential is reached (about 200 mV), protons pass through special channels in ATP-somes containing oxidative phosphorylation enzymes. At this moment, electrons give up their energy to add phosphoric acid residues to AMP to form ADP and to ADP to form ATP. The electrons that have given up energy combine with protons to form hydrogen atoms. Hydrogen combines with oxygen to form water. Thus, the final electron acceptor is oxygen.
“Cell vital activity” - Metabolism and respiration. Lesson objectives: To become familiar with the basic life processes of a cell. Development - the structure of the cell becomes more complex. Nutrition - nutrients enter the cell. Unnecessary substances. Vital activity of the cell. Basic processes of cell life. Nutrients.
"Cells" - The main parts of a cell -. With a nucleus - a eukaryotic cell. Cells are different: The energy station of the cell. The cell is the structural and functional unit of all living things. Cytoplasm. Mitochondria. Leucoplasts are colorless plastids. The smallest structures of a cell. Chromoplasts - yellow, red, brown plastids.
“Study of the cell” - Table 2. Calculation of microscope magnification. Main parts of the cell. A microscope is a device for studying small objects. Types of cells. Sex cells. Vital activity of the cell. Modern magnifying devices. Nerve cell Muscle cell Epithelial cell. Preparation of a microslide. Microscope.
“Prokaryotic cell” - Reproduction of bacteria. Prevention of diseases. Biotechnology has made it possible to obtain bacteria with properties never seen before. Bacteria in nature. Some bacteria live permanently in the human body (in the digestive system). Number of bacteria in 1cm3 of water. BIOTECHNOLOGY. chemical bionics. 1. Comparative characteristics of cells.
“Cell division grade 6” - Life cycle of a cell: (Fill out the diagram). Describe the state of the cell. Chromosomes are not visible because... Chromosome duplication. Methods of cell division. What is the secret of this division? Phases of mitosis. Interphase Doubling of organelles, doubling of chromosomes, formation of organic substances. Cell before division. The meaning of mitosis.
(Answers at the end of the test)
A1. To identify changes occurring in a living cell during the process of mitosis, the method is used
1) centrifugation
2) gene transplantation
3) labeled atoms
4) microscopy
A2. The similarity in the structure and functioning of the cells of all organisms indicates their
1) relationship
2) diversity
3) evolution
4) fitness
A3. In cell lysosomes, as in mitochondria, there is
1) photosynthesis
2) chemosynthesis
3) energy metabolism
4) plastic exchange
A4. The chromosome set in a woman’s somatic cells consists of
1) 44 autosomes and two X chromosomes
2) 44 autosomes and two Y chromosomes
3) 44 autosomes and X- and Y-chromosomes
4) 22 pairs of autosomes and X- and Y-chromosomes
A5. Prokaryotes include
1) algae
2) protozoa
4) cyanobacteria
A6. The process of asexual reproduction in animals is based on
3) gametogenesis
4) fertilization
A7. How many types of gametes are formed in a parent organism with the aaBb genotype during linked inheritance?
A8. What law will manifest itself in the inheritance of traits when crossing organisms with genotypes: Aa x Aa?
1) uniformity
2) splitting
3) linked inheritance
4) independent inheritance
A9. Albinism (appearance of white leaves) in tobacco plants is a result of
1) lack of light
2) disorders of gametogenesis
3) gene mutation
4) modification variability
A10. The main task of taxonomy is to study
1) stages of historical development of organisms
2) relationships between organisms and the environment
3) adaptability of organisms to living conditions
4) diversity of organisms and establishment of their relationships
A11. An underground shoot differs from a root in that it has
2) growth zones
3) vessels
A12. The main feature by which plants are grouped into families is their structural features.
2) flower and fruit
3) leaves and stem
4) root system
A13. Arterial blood in the heart does not mix with venous blood
1) most reptiles
2) birds and mammals
3) tailed amphibians
4) tailless amphibians
A14. The semi-movable connection of the spinal bones is ensured by
1) cartilaginous layers
2) bone processes
3) bone sutures
4) articular surfaces
A15. The process of recognition and destruction of foreign proteins by leukocytes underlies
1) immunity
2) blood clotting
3) hematopoietic function of the bone marrow
4) humoral regulation
A16. Changes in blood sugar occur as a result of impaired activity
1) pituitary gland
2) pancreas
4) thyroid gland
A17. A patient with diphtheria is administered anti-diphtheria serum, which contains
1) fibrinogen
2) weakened microbes
3) ready-made antibodies
4) hemoglobin
A18. Guided by genetic criteria alone, it is impossible to determine the species, since
1) the ranges of different species coincide
2) the set of chromosomes in different species may be the same
3) different species live in similar conditions
4) individuals of different species are similar in appearance
A19. The genetic heterogeneity of individuals in a population increases
1) mutational variability
2) geographical isolation
3) struggle for existence
4) artificial selection
A20. What evidence of evolution includes the similarity of stages of individual development of animal embryos?
1) embryological
2) paleontological
3) comparative anatomical
4) molecular genetic
A21. Aromorphic changes in the ancestors of amphibians include the appearance
2) pulmonary respiration
3) streamlined body shape
4) protective coloring
A22. What are the factors that determine the survival limits of a species called?
1) abiotic
2) anthropogenic
3) optimal
4) limiting
A23. The similarity between artificial and natural ecosystems is that they
2) have the same plant biomass productivity
3) cannot exist without human participation
A24. The continuous flow of chemical elements from inanimate nature into living nature and back, carried out as a result of the vital activity of organisms, is called
1) power circuits
2) food connections
3) biogenic migration of atoms
4) the rule of the ecological pyramid
A25. In the Golgi complex occurs
1) ATP formation
2) oxidation of organic substances
3) accumulation of substances synthesized in the cell
4) synthesis of protein molecules
A26. What number of nucleotides in mRNA encodes the sequence of 14 amino acids in a protein?
A27. Determine the number of chromosomes in the telophase of mitosis in the endosperm cells of an onion seed (endosperm cells have a triploid set of chromosomes), if the onion root cells contain 16 chromosomes.
A28. The diploid set of bread wheat has 42 chromosomes. The new variety obtained on its basis has 84 chromosomes due to
1) changes in reaction norm
2) cytoplasmic mutation
3) chromosomal rearrangements
4) genomic mutation
A29. Distant hybrids are usually sterile because they
1) cells do not divide by mitosis
2) DNA replication does not occur in cells
3) gametes vary in size
4) chromosome conjugation in meiosis is disrupted
A30. What adaptation in plants helps reduce water evaporation?
1) tiered arrangement of plants in the community
2) mosaic arrangement of leaves on the stem
3) location of stomata on the underside of the leaf
4) the presence of photosynthetic tissue
A31. The energy used by a person in the process of life is released in cells when
1) oxidation of organic substances
2) protein biosynthesis
3) splitting polymers into monomers
4) transport of nutrients in the blood
A32. Mixed secretion glands are
1) liver and sweat
2) salivary and lacrimal
3) pancreas and genitals
4) thyroid and pituitary gland
A33. Genetic drift is
1) random change in the frequency of occurrence of their alleles in the population
2) movement of individuals from one population to another
4) the result of natural selection
A34. The upper limit of life in the biosphere is determined by the high concentration
1) carbon dioxide
2) water vapor
3) heat rays
4) ultraviolet rays
The answer to the tasks in this part (B1–B8) is a sequence of numbers.
In tasks B1–B3, choose three correct answers out of six.
IN 1. Indicate the features of modification variability.
1) occurs suddenly
2) manifests itself in individual individuals of the species
3) changes are due to the reaction norm
4) manifests itself similarly in all individuals of the species
5) is adaptive in nature
6) passed on to offspring
AT 2. Visual analyzer includes
1) the white membrane of the eye
2) retinal receptors
3) vitreous body
4) sensory nerve
5) occipital cortex
6) lens
AT 3. What features characterize driving selection?
1) operates under relatively constant living conditions
2) eliminates individuals with an average trait value
3) promotes the reproduction of individuals with an altered genotype
4) preserves individuals with deviations from the average values of the trait
5) preserves individuals with an established norm of reaction of the trait
6) promotes the appearance of mutations in the population
In tasks B4–B6, for each element of the first column, select the corresponding element of the second and write down the selected numbers in the table under the corresponding letters.
AT 4. Establish a correspondence between the characteristic of an organism and the kingdom to which it belongs.
AT 5. Establish a correspondence between the function of the human nervous system and the department that performs this function.
AT 6. Establish a correspondence between the characteristics of autotrophic nutrition and its type.
AT 7. Arrange the blood vessels in order of decreasing speed of blood movement in them.
1) superior vena cava
3) brachial artery
4) capillaries
AT 8. Establish the sequence of evolutionary processes on Earth in chronological order.
1) the emergence of prokaryotic cells
2) formation of coacervates in water
3) the emergence of eukaryotic cells
4) emergence of organisms onto land
5) the emergence of multicellular organisms
Answers.
Answer | Answer |
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Answer | Answer |
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A1, B2, C1, D2, D2 |
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A2, B1, B2, G1, D1, E2 |
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A1, B2, B1, D1, D2, E1 |
Morphobiological characteristics of the main cell organelles (ribosomes, mitochondria, Golgi complex, lysosomes, endoplasmic reticulum).
1. Ribosomes
· Structure: ultramicroscopic organelles, round or mushroom-shaped, consisting of 2 parts - subunits. They do not have a membrane structure and consist of protein and r-RNA. Subunits are formed in the nucleolus. They are united along the mRNA molecule into chains - polyribosomes - in the cytoplasm.
· Functions: universal organelles of all animal and plant cells. They are found in the cytoplasm in a free state or on the membranes of the ER; in addition to those found in mitochondria and chloroplasts. Proteins are synthesized in ribosomes according to the principle of matrix synthesis; a polypeptide chain is formed - the primary structure of the protein molecule.
2. Mitochondria
· Structure: microscopic organelles with a 2-membrane structure. The outer membrane is smooth, the inner one acquires outgrowths (cristae). The semi-liquid substance of mitochondria contains enzymes: ribosomes, DNA, RNA. They reproduce by division.
· Functions: are the respiratory and energy center of the cell.
3. Golgi complex
· Structure: microscopic 1 membrane organelles, consisting of a chain of flat tanks, along the edges of which tubes branch off, separating small vesicles. They have 2 poles: construction and secretory.
· Functions: products of synthesis, decay and substances entering the cell, as well as substances that are removed from the cell, accumulate in the tanks. Packed in vesicles, they enter the cytoplasm: some are used, others are excreted. In plant cells they participate in the construction of the cell wall.
4. Lysosomes
· Structure: microscopic 1 membrane organelles, round in shape. Their number depends on the vital activity of the cell and its physiological state. Lysosomes contain lysing (dissolving) enzymes synthesized on ribosomes. Separated from dictyosomes in the form of vesicles.
· Functions: digestion of food that enters an animal cell during phagocytosis, protective function. In the cells of any organisms, it carries out autolysis (self-dissolution of organelles, especially under conditions of food or oxygen starvation. In plants, organelles dissolve during the formation of cork tissue, wood vessels, and fibers.
5. Endoplasmic reticulum or endoplasmic reticulum
· Structure: an ultramicroscopic system of membranes that forms tubes, tubules, cisterns, and vesicles. The structure of the membranes is universal (as well as the outer one), the entire network is united into a single whole with the outer membrane of the nuclear membrane and the outer cellular membrane. The granular ER carries ribosomes, while the smooth one does not.
· Functions: ensures the transport of substances both within the cell and between neighboring cells. Divides the cell into separate sections in which various physiological processes and chemical reactions simultaneously occur. Granular EPS is involved in protein synthesis. In the EPS channels, protein molecules acquire secondary, tertiary and quaternary structures, fats are synthesized and ATP is transported.