Comparative characteristics of eukaryotic cells of plants, fungi, animals. Comparison of the cell structure of bacteria, plants and animals. Features of the structure of plant, animal and fungal cells

Similarities and differences in the structure of cells of plants, animals and fungi

Similarities in the structure of eukaryotic cells.

Now it is impossible to say with complete certainty when and how life arose on Earth. We also do not know exactly how the first living creatures on Earth ate: autotrophic or heterotrophic. But at present, representatives of several kingdoms of living beings coexist peacefully on our planet. Despite the great difference in structure and lifestyle, it is obvious that there are more similarities between them than differences, and they all probably have common ancestors who lived in the distant Archean era. The presence of common “grandfathers” and “grandmothers” is evidenced by a number of common characteristics in eukaryotic cells: protozoa, plants, fungi and animals. These signs include:

General plan of the cell structure: the presence of a cell membrane, cytoplasm, nucleus, organelles;
- fundamental similarity of metabolic and energy processes in the cell;
- coding of hereditary information using nucleic acids;
- unity of the chemical composition of cells;
- similar processes of cell division.

Differences in the structure of plant and animal cells.

In the process of evolution, due to the unequal conditions of existence of cells of representatives of different kingdoms of living beings, many differences arose. Let's compare the structure and vital activity of plant and animal cells (Table 4).

The main difference between the cells of these two kingdoms is the way they are nourished. Plant cells containing chloroplasts are autotrophs, that is, they themselves synthesize the organic substances necessary for life using light energy during the process of photosynthesis. Animal cells are heterotrophs, i.e., the source of carbon for the synthesis of their own organic substances is organic substances supplied with food. These same nutrients, such as carbohydrates, serve as a source of energy for animals. There are exceptions, such as green flagellates, which are capable of photosynthesis in the light and feed on ready-made organic substances in the dark. To ensure photosynthesis, plant cells contain plastids that carry chlorophyll and other pigments.

Since a plant cell has a cell wall that protects its contents and ensures its constant shape, when dividing between daughter cells, a partition is formed, and an animal cell, which does not have such a wall, divides to form a constriction.

Features of fungal cells.

Thus, the separation of fungi into an independent kingdom, numbering more than 100 thousand species, is absolutely justified. Mushrooms originate either from ancient filamentous algae that have lost chlorophyll, i.e., from plants, or from some ancient heterotrophs unknown to us, i.e., animals.

1. How does a plant cell differ from an animal cell?
2. What are the differences in the division of plant and animal cells?
3. Why are mushrooms separated into an independent kingdom?
4. What do they have in common and what differences in structure and life can be identified by comparing mushrooms with plants and animals?
5. Based on what features can we assume that all eukaryotes had common ancestors?

Kamensky A. A., Kriksunov E. V., Pasechnik V. V. Biology 10th grade
Submitted by readers from the website

2.4. The structure of pro- and eukaryotic cells. The relationship between the structure and functions of the parts and organelles of a cell is the basis of its integrity

Basic terms and concepts tested in the examination paper: apparatus

Golgi, vacuole, cell membrane, cell theory, leukoplasts, mitochondria, cell organelles, plastids, prokaryotes, ribosomes, chloroplasts, chromoplasts, chromosomes, eukaryotes, nucleus.

Any cell is a system. This means that all its components are interconnected, interdependent and interact with each other. This also means that disruption of one of the elements of a given system leads to changes and disruptions in the functioning of the entire system. A collection of cells forms tissues, various tissues form organs, and organs, interacting and performing a common function, form organ systems. This chain can be continued further, and you can do it yourself. The main thing to understand is that any system has a certain structure, level of complexity and is based on the interaction of the elements that make it up. Below are reference tables that compare the structure and functions of prokaryotic and eukaryotic cells, and also understand their structure and functions. Carefully analyze these tables, because exam papers often ask questions that require knowledge of this material.

2.4.1. Features of the structure of eukaryotic and prokaryotic cells. Comparative data

Comparative characteristics of eukaryotic and prokaryotic cells.

The structure of eukaryotic cells.

Functions of eukaryotic cells. The cells of unicellular organisms carry out all the functions characteristic of living organisms - metabolism, growth, development, reproduction; capable of adaptation.

The cells of multicellular organisms are differentiated by structure, depending on the functions they perform. Epithelial, muscle, nervous, and connective tissues are formed from specialized cells.

EXAMPLES OF TASKS Part A

A1. Prokaryotic organisms include 1) bacillus 2) hydra 3) amoeba 4) volvox

A2. The cell membrane performs the function

1) protein synthesis

2) transmission of hereditary information

3) photosynthesis

4) phagocytosis and pinocytosis

A3. Indicate the point where the structure of the named cell coincides with its function

1) neuron - abbreviation

2) leukocyte – impulse conduction

3) erythrocyte – transport of gases

4) osteocyte - phagocytosis

A4. Cellular energy is produced in

1) ribosomes 3) nucleus

2) mitochondria 4) Golgi apparatus

A5. Eliminate an unnecessary concept from the proposed list

1) lamblia 3) ciliates

2) plasmodium 4) chlamydomonas

A6. Eliminate an unnecessary concept from the proposed list

1) ribosomes 3) chloroplasts

2) mitochondria 4) starch grains

A7. Cell chromosomes perform the function

1) protein biosynthesis

2) storage of hereditary information

3) formation of lysosomes

4) regulation of metabolism

IN 1. Select the functions of chloroplasts from the list provided

1) formation of lysosomes 4) ATP synthesis

2) synthesis of glucose 5) release of oxygen

3) RNA synthesis 6) cellular respiration

AT 2. Select structural features of mitochondria

1) surrounded by a double membrane

2) contain chlorophyll

3) there are cristae

4) folded outer membrane

5) surrounded by a single membrane

6) the inner membrane is rich in V3 enzymes. Match the organelle with its function

AT 4. Fill out the table, marking with “+” or “-” signs the presence of the indicated structures in pro- and eukaryotic cells

C1. Prove that the cell is an integral biological, open system.

2.5. Metabolism: energy and plastic metabolism, their relationship. Enzymes, their chemical nature, role in metabolism. Stages of energy metabolism. Fermentation and respiration. Photosynthesis, its significance, cosmic role. Phases of photosynthesis. Light and dark reactions of photosynthesis, their relationship. Chemosynthesis. The role of chemosynthetic bacteria on Earth

Terms tested in the examination paper: autotrophic organisms

anabolism, anaerobic glycolysis, assimilation, aerobic glycolysis, biological oxidation, fermentation, dissimilation, biosynthesis, heterotrophic organisms, respiration, catabolism, oxygen stage, metabolism, plastic metabolism, preparatory stage, light phase of photosynthesis, dark phase of photosynthesis, photolysis of water, photosynthesis, energy metabolism.

2.5.1. Energy and plastic metabolism, their relationship

Metabolism (metabolism) is a set of interconnected processes of synthesis and breakdown of chemicals occurring in the body. Biologists divide it into plastic (anabolism) and energy metabolism (catabolism), which are interconnected. All synthetic processes require substances and energy supplied by fission processes. Decomposition processes are catalyzed by enzymes synthesized during plastic metabolism, using the products and energy of energy metabolism.

For individual processes occurring in organisms, the following terms are used:

Anabolism (assimilation) is the synthesis of more complex monomers from simpler ones with the absorption and accumulation of energy in the form of chemical bonds in the synthesized substances.

Catabolism (dissimilation) is the breakdown of more complex monomers into simpler ones with the release of energy and its storage in the form of high-energy bonds of ATP.

Living beings use light and chemical energy for their life. Green plants - autotrophs - synthesize organic compounds during the process of photosynthesis, using the energy of sunlight. Their source of carbon is carbon dioxide. Many autotrophic prokaryotes obtain energy through the process of chemosynthesis - the oxidation of inorganic compounds. For them, the source of energy can be compounds of sulfur, nitrogen, and carbon. Heterotrophs use organic sources of carbon, i.e. feed on ready-made organic matter. Among the plants there may be those that feed in a mixed way (mixotrophically) - sundew, Venus flytrap or even heterotrophically - rafflesia. Among the representatives of unicellular animals, green euglena are considered mixotrophs.

Enzymes, their chemical nature, role in metabolism . Enzymes are always specific proteins - catalysts. The term “specific” means that the object in relation to which this term is used has unique features, properties, and characteristics. Each enzyme has such characteristics because, as a rule, it catalyzes a certain type of reaction. Not a single biochemical reaction in the body occurs without the participation of enzymes. The specificity of the enzyme molecule is explained by its structure and properties. An enzyme molecule has an active center, the spatial configuration of which corresponds to the spatial configuration of the substances with which the enzyme interacts. Having recognized its substrate, the enzyme interacts with it and accelerates its transformation.

Enzymes catalyze all biochemical reactions. Without their participation, the rate of these reactions would decrease hundreds of thousands of times. Examples include reactions such as the participation of RNA polymerase in the synthesis of mRNA on DNA, the effect of urease on urea, the role of ATP synthetase in the synthesis of ATP, and others. Note that many enzymes have names that end in “aza.”

The activity of enzymes depends on temperature, acidity of the environment, and the amount of substrate with which it interacts. As temperature increases, enzyme activity increases. However, this happens up to certain limits, because At high enough temperatures, the protein denatures. The environment in which enzymes can function is different for each group. There are enzymes that are active in an acidic or slightly acidic environment or in an alkaline or slightly alkaline environment. In an acidic environment, gastric juice enzymes are active in mammals. In a slightly alkaline environment, intestinal juice enzymes are active. The pancreatic digestive enzyme is active in an alkaline environment. Most enzymes are active in a neutral environment.

2.5.2. Energy metabolism in the cell (dissimilation)

Energy exchange is a set of chemical reactions of the gradual decomposition of organic compounds, accompanied by the release of energy, part of which is spent on the synthesis of ATP. The processes of breakdown of organic compounds in aerobic organisms occur in three stages, each of which is accompanied by

In multicellular organisms it is carried out by digestive enzymes. In unicellular organisms - by lysosome enzymes. At the first stage, protein breakdown occurs

to amino acids, fats to glycerol and fatty acids, polysaccharides to monosaccharides,

nucleic acids to nucleotides. This process is called digestion.

The second stage is oxygen-free (glycolysis). Its biological meaning lies in the beginning of the gradual breakdown and oxidation of glucose with the accumulation of energy in the form of 2 ATP molecules. Glycolysis occurs in the cytoplasm of cells. It consists of several sequential reactions of converting a glucose molecule into two molecules of pyruvic acid (pyruvate) and two molecules of ATP, in the form of which part of the energy released during glycolysis is stored: C6H12O6 + 2ADP + 2P → 2C3H4O3 + 2ATP. The rest of the energy is dissipated as heat.

In yeast and plant cells ( with a lack of oxygen) pyruvate breaks down into ethyl alcohol and carbon dioxide. This process is called alcoholic fermentation.

The energy accumulated during glycolysis is too little for organisms that use oxygen for their respiration. That is why in the muscles of animals, including humans, under heavy loads and lack of oxygen, lactic acid (C3H6O3) is formed, which accumulates in the form of lactate. Muscle pain appears. This happens faster in untrained people than in trained people.

The third stage is oxygen, consisting of two sequential processes - the Krebs cycle, named after Nobel laureate Hans Krebs, and oxidative phosphorylation. Its meaning is that during oxygen respiration, pyruvate is oxidized to the final products - carbon dioxide and water, and the energy released during oxidation is stored in the form of 36 ATP molecules. (34 molecules in the Krebs cycle and 2 molecules during oxidative phosphorylation). This energy of decomposition of organic compounds provides reactions of their synthesis in plastic exchange. The oxygen stage arose after the accumulation of a sufficient amount of molecular oxygen in the atmosphere and the appearance of aerobic organisms.

Oxidative phosphorylation or cellular respiration occurs when

the inner membranes of mitochondria, into which electron transport molecules are built. During this stage, most of the metabolic energy is released. Carrier molecules transport electrons to molecular oxygen. Some of the energy is dissipated as heat, and some is spent on the formation of ATP.

Total reaction of energy metabolism:

С6Н12O6 + 6O2 → 6СО2 + 6Н2O + 38ATP.

EXAMPLES OF TASKS Part A

A1. The feeding method of carnivorous animals is called

1) autotrophic 3) heterotrophic

2) mixotrophic 4) chemotrophic

A2. The set of metabolic reactions is called:

1) anabolism 3) dissimilation

2) assimilation 4) metabolism

A3. At the preparatory stage of energy metabolism, the formation occurs:

1) 2 molecules of ATP and glucose

2) 36 molecules of ATP and lactic acid

3) amino acids, glucose, fatty acids

4) acetic acid and alcohol

A4. Substances that catalyze biochemical reactions in the body are:

1) proteins 3) lipids

2) nucleic acids 4) carbohydrates

A5. The process of ATP synthesis during oxidative phosphorylation occurs in:

1) cytoplasm 3) mitochondria

2) ribosomes 4) Golgi apparatus

A6. The ATP energy stored during energy metabolism is partially used for reactions:

1) preparatory stage

2) glycolysis

3) oxygen stage

4) synthesis of organic compounds A7. The products of glycolysis are:

1) glucose and ATP

2) carbon dioxide and water

3) pyruvic acid and ATP

4) proteins fats carbohydrates

IN 1. Select the events that occur during the preparatory stage of energy metabolism in humans

1) proteins are broken down into amino acids

2) glucose is broken down into carbon dioxide and water

3) 2 ATP molecules are synthesized

4) glycogen is broken down into glucose

5) lactic acid is formed

6) lipids are broken down into glycerol and fatty acids

AT 2. Correlate the processes occurring during energy metabolism with the stages at which they occur

VZ. Determine the sequence of transformations of a piece of raw potato in the process of energy metabolism in the pig’s body:

A) formation of pyruvate B) formation of glucose

C) absorption of glucose into the blood D) formation of carbon dioxide and water

E) oxidative phosphorylation and formation of H2O E) Krebs cycle and formation of CO2

C1. Explain the reasons for fatigue among marathon athletes at distances, and how is it overcome?

2.5.3. Photosynthesis and chemosynthesis

All living things need food and nutrients. When feeding, they use energy stored primarily in organic compounds - proteins, fats, carbohydrates. Heterotrophic organisms, as already mentioned, use food of plant and animal origin, already containing organic compounds. Plants create organic matter through the process of photosynthesis. Research into photosynthesis began in 1630 with the experiments of the Dutchman van Helmont. He proved that plants do not obtain organic matter from the soil, but create it themselves. Joseph Priestley in 1771 proved the “correction” of air with plants. Placed under a glass cover, they absorbed carbon dioxide released by the smoldering splinter. Research has continued, and it has now been established that photosynthesis is the process of formation of organic compounds from carbon dioxide (CO2) and water using light energy and takes place in the chloroplasts of green plants and the green pigments of some photosynthetic bacteria.

Chloroplasts and folds of the cytoplasmic membrane of prokaryotes contain a green pigment - chlorophyll. The chlorophyll molecule is capable of being excited by sunlight and donating its electrons and moving them to higher energy levels. This process can be compared to throwing a ball up. As the ball rises, it stores potential energy; falling, he loses her. The electrons do not fall back, but are picked up by electron carriers (NADP+ - nicotinamide diphosphate). In this case, the energy they previously accumulated is partially spent on the formation of ATP. Continuing the comparison with a thrown ball, we can say that the ball, as it falls, heats the surrounding space, and part of the energy of the falling electrons is stored in the form of ATP. The process of photosynthesis is divided into reactions caused by light and reactions associated with carbon fixation. They are called light

and dark phases.

Comparison of the structure of cells of bacteria, plants and animals Cellular structure Function Bacteria Plants Animals Nucleus Storage of hereditary information, RNA synthesis No Yes Yes Chromosome Hereditary material consisting of linear DNA No Yes ... Wikipedia

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Epithelial cells. Cell theory is one of the generally accepted biological generalizations that affirm the unity of the principle of the structure and development of the world of plants, animals and other living organisms with a cellular structure in which the cell ... ... Wikipedia

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The science that studies the structure and function of cells - cytology .

Cells can differ from each other in shape, structure and function, although the basic structural elements of most cells are similar. Systematic groups of cells – prokaryotic And eukaryotic (superkingdoms prokaryotes and eukaryotes) .

Prokaryotic cells do not contain a true nucleus and a number of organelles (the kingdom of the crushed cell).
Eukaryotic cells contain a nucleus in which the hereditary apparatus of the organism is located (superkingdoms fungi, plants, animals).

Any organism develops from a cell.
This applies to organisms that were born as a result of both asexual and sexual methods of reproduction. That is why the cell is considered the unit of growth and development of the organism.

According to the method of nutrition and cell structure, they are divided into kingdoms :

• Drobyanki;
• Mushrooms;
• Plants;
• Animals.

Bacterial cells (kingdom Drobyanka) have: a dense cell wall, one circular DNA molecule (nucleoid), ribosomes. These cells lack many organelles characteristic of eukaryotic plant, animal and fungal cells. Based on their feeding method, bacteria are divided into phototrophs, chemotrophs, and heterotrophs.

Fungal cells covered with a cell wall that differs in chemical composition from the cell walls of plants. It contains chitin, polysaccharides, proteins and fats as its main components. The reserve substance of fungal and animal cells is glycogen.

Plant cells contain: chloroplasts, leucoplasts and chromoplasts; they are surrounded by a dense cell wall of cellulose and also have vacuoles with cell sap. All green plants are autotrophic organisms.

U animal cells no dense cell walls. They are surrounded by a cell membrane through which the exchange of substances with the environment occurs.

THEMATIC TASKS

Part A

A1. Which of the following is consistent with the cell theory?
1) the cell is an elementary unit of heredity
2) the cell is a unit of reproduction
3) the cells of all organisms are different in their structure
4) the cells of all organisms have different chemical compositions

A2. Precellular life forms include:
1) yeast
2) penicillium
3) bacteria
4) viruses

A3. A plant cell differs from a fungal cell in structure:
1) cores
2) mitochondria
3) cell wall
4) ribosomes

A4. One cell consists of:
1) influenza virus and amoeba
2) mucor mushroom and cuckoo flax
3) planaria and volvox
4) green euglena and slipper ciliates

A5. Prokaryotic cells have:
1) core
2) mitochondria
3) Golgi apparatus
4) ribosomes

A6. The species of the cell is indicated by:
1) core shape
2) number of chromosomes
3) membrane structure
4) primary protein structure

A7. The role of cell theory in science is
1) opening of the cell nucleus
2) opening the cell
3) generalization of knowledge about the structure of organisms
4) discovery of metabolic mechanisms

Part B

IN 1. Select features characteristic only of plant cells
1) there are mitochondria and ribosomes
2) cell wall made of cellulose
3) there are chloroplasts
4) storage substance – glycogen
5) reserve substance – starch
6) the nucleus is surrounded by a double membrane

AT 2. Select the characteristics that distinguish the kingdom of Bacteria from the rest of the kingdoms of the organic world.
1) heterotrophic mode of nutrition
2) autotrophic method of nutrition
3) the presence of a nucleoid
4) absence of mitochondria
5) absence of a core
6) presence of ribosomes

VZ. Find a correspondence between the structural features of the cell and the kingdoms to which these cells belong

Part C

C1. Give examples of eukaryotic cells that do not have a nucleus.
C2. Prove that cell theory generalized a number of biological discoveries and predicted new discoveries.

1. What are living organisms whose cells contain a formed nucleus called?

Autotrophs, heterotrophs, prokaryotes, eukaryotes.

Living organisms whose cells contain a formed nucleus are called eukaryotes.

2. What are the similarities between the cells of protists, fungi, plants and animals?

● Cells are arranged according to a single plan and consist of three main parts: the surface apparatus (including the cytoplasmic membrane and the supramembrane complex), the cytoplasm (which includes the hyaloplasm, cytoskeleton, inclusions, various membrane and non-membrane organelles) and the nucleus.

● Metabolism and energy processes occur in a similar way.

● Similar methods of cell division.

3. How does a plant cell differ from an animal cell?

● The supramembrane complex of a plant cell is represented by a rigid cell wall. The supra-membrane complex of an animal cell is the glycocalyx.

● Unlike animal cells, plant cells are characterized by the presence of plastids (chloroplasts, leucoplasts, chromoplasts) and large vacuoles.

● Animal cells are characterized by the presence of centrioles, which are absent in the cells of most plants.

● Reserve polysaccharide, which is deposited in plant cells – starch. Another polysaccharide, glycogen, is deposited in animal cells.

And (or) other significant features.

4. What common features and what differences can be identified by comparing cells of different groups of protists?

Based on the type of nutrition, there are three groups of protists: autotrophic, autoheterotrophic and heterotrophic. Autotrophic and autoheterotrophic protists are called algae.

Similarities:

● All protists are eukaryotes, therefore, their cells are characterized by the presence of a plasmalemma, nucleus and cytoplasm, including hyaloplasm, cytoskeleton, inclusions, various membrane and non-membrane organelles.

Differences:

● Algae cells contain chloroplasts (from one to several dozen) and carry out photosynthesis. There are no plastids in the cells of heterotrophic protists.

● Unlike heterotrophic protists, many algae have a cell wall and vacuoles with cell sap. In the cells of heterotrophic protists, unlike algae, there are digestive vacuoles.

● Some unicellular algae have a light-sensitive eye, but the cells of heterotrophic protists do not.

● Unlike autotrophic protists, autoheterotrophic ones can not only carry out photosynthesis, but also absorb organic substances dissolved in water over the entire surface of the body.

● Among algae there are unicellular, colonial and multicellular forms. Heterotrophic protists are mostly unicellular.

And (or) other significant features.

5. Compare the cells of fungi, plants and animals according to various criteria. Indicate the similarities and differences between them.

Similarities:

● Eukaryotes, their cells are covered with plasma membrane, contain a nucleus and cytoplasm, which includes hyaloplasm, cytoskeleton, inclusions, various membrane and non-membrane organelles. Membrane organelles, the presence of which is characteristic of cells of all three kingdoms, are: ER, Golgi complex, lysosomes and mitochondria; non-membrane organelles are ribosomes.

● The genetic apparatus is represented by linear DNA molecules associated with special nuclear proteins.

● Similar metabolic processes and methods of cell division.

● They are multicellular (with the exception of some fungi).

Differences:

● The supra-membrane complex of animal cells is represented by the glycocalyx, and of plants and fungi by the cell wall, and its basis in plants is cellulose, and in fungi it is chitin.

● The type of nutrition of plants is autotrophic (cells contain chloroplasts and other plastids, photosynthesis occurs), fungi and animals are heterotrophic (no plastids).

● The storage carbohydrate of fungal and animal cells is glycogen. Starch is stored in plant cells.

● Unlike fungi and plants, animal cells are not characterized by the presence of vacuoles with cell sap.

● The cell center is present in most animal cells, but absent in most plants and fungi.

And (or) other significant features.

Fungal cells are protected by a strong cell wall, the basis of which is chitin fibrils. Chitin is not digested in humans and most animals due to the absence of the enzyme chitinase. Therefore, proteins and other nutrients contained in intact fungal cells (which have preserved the integrity of the chitinous membrane) are inaccessible for absorption.

7*. Scientists suggest that the first (most ancient) living organisms on Earth were hereditary material (DNA, RNA), which was surrounded by a viscous solution of proteins and limited from the external environment by a membrane. Suggest hypotheses about how, during the process of evolution, the nucleus and various organelles characteristic of modern eukaryotic cells could arise.

For example, the autogenous hypothesis suggests that the eukaryotic cell arose through the differentiation of an original prokaryotic cell. First, the outer membrane was formed, then from its invaginations, separate structures formed, forming the nuclear envelope and giving rise to organelles.

The symbiotic hypothesis (now more often called the theory of symbiogenesis or the theory of endosymbiosis) suggests that the eukaryotic cell arose as a result of several successive symbioses.

First, large amoeba-shaped prokaryotic cells united with small aerobic bacteria, which turned into mitochondria. Then large amoeboid cells entered into symbiosis with spirochete-like bacteria (bacteria with long, spirally twisted cells), from which centrioles and flagella were formed. Gradually, the nucleus became isolated.

Nuclear cells with the simplest set of organelles could become the ancestors of heterotrophic flagellated protists, from which fungi and animals evolved. The symbiosis of nuclear cells with cyanobacteria, transformed into chloroplasts, led to the formation of unicellular algae. Later, plants evolved from algae.

*Tasks marked with an asterisk require students to put forward various hypotheses. Therefore, when marking, the teacher should focus not only on the answer given here, but take into account each hypothesis, assessing the biological thinking of students, the logic of their reasoning, the originality of ideas, etc. After this, it is advisable to familiarize students with the answer given.