Mushrooms - biology exam. Glycogen is the reserve nutrient of fungi 3 The reserve nutrient of fungi is

Mushrooms- one of the largest and most prosperous groups of organisms. These are eukaryotes that do not have chlorophyll, and therefore, they feed on ready-made organic substances, like animals, and glycogen is a reserve nutrient. However, they have a rigid cell wall, they are not able to move, like plants, so they were allocated to a special kingdom.

Mushroom reproduction happens in three ways:

Widely known hat mushrooms - chanterelles, fly agaric, white, milk mushrooms. Them fruit bodies represented by a stem and a cap, consist of tightly fitting mycelium filaments. Hats are dyed. There are tubular cap mushrooms, in which the lower layer of the cap is formed by tubules ( porcini, boletus) and lamellar, with a lower layer of plates (russula, chanterelles). Millions of spores are formed in tubules and plates.

mold mushrooms- mucor and penicillium, develop on food residues, in soil, manure, on fruits. Penicillium produces substances that have a detrimental effect on bacteria. They are isolated and used to treat inflammatory diseases. This group also includes yeast - which can form colonies, this is used in baking.

Useful value of mushrooms:

Saprophytic fungi, together with soil bacteria, influence the formation of the soil, as they decompose organic matter to inorganic.
Together with bacteria, saprophytic fungi are used to treat wastewater.
One of the most ancient uses of mushrooms is fermentation.
The most famous varieties of cheese are the product of the simultaneous work of bacteria and various kinds mushrooms.
Obtaining antibiotics - for example, penicillin.
Some mushrooms are the most convenient objects for research and genetic engineering.
They are a cheap source of feed protein.

Harmful value of mushrooms:

Saprophytic fungi, settling on food and various organic materials may cause damage to them.
causative agents of various diseases.

Mushrooms ( Mycota)

Mushrooms are heterotrophic organisms, the body of which is called mycelium (mycelium), consisting of individual threads - hyphae with apical (apical) growth and lateral branching. The mycelium penetrates the substrate and absorbs nutrients from it with its entire surface (substrate mycelium), and is also located on its surface and can rise above the substrate (surface and aerial mycelium). Reproductive organs are usually formed on aerial mycelium.

There are non-cellular, or cenotic mycelium, devoid of partitions and representing, as it were, one giant cell with a large number nuclei, and cellular, or septate mycelium, divided by partitions - septa into individual cells containing from one to many nuclei. For representatives of the classes of chytridiomycetes, oomycetes and zygomycetes, conventionally called lower mushrooms, non-cellular mycelium is characteristic. Everyone has higher mushrooms- ascomycetes, bisidiomycetes and deuteromycetes - cell mycelium.

The cell wall contains chitin. The reserve nutrient is glycogen (animal starch).

Fungi reproduce vegetatively, asexually and sexually.

According to the structure of the mycelium and the characteristics of sexual reproduction, six main classes of fungi are distinguished: Chytridiomycetes- chytridiomycetes, Zygomycetes- zygomycetes, Ascomycetes- ascomycetes, Basidiomycetes- basidiomycetes, Oomycetes- oomycetes and Deuteromycetes- deuteromycetes.

In medicine, from the class of ascomycetes, or marsupial fungi, baker's yeast and ergot are used, from the class of basidiomycetes - chaga (tinder fungus or birch fungus), from deuteromycetes - species of the genus penicillium.

A revolutionary event in the history of medicine was the discovery of the first antibiotic penicillin, obtained from fungi of the genus Penicillium. Penicillin is active against all staphylococcal infections and gram-positive bacteria and is almost non-toxic to humans. Despite the fact that at present many synthetic derivatives of penicillin have been introduced into medical practice, the basis for obtaining this medicinal raw material is the industrial cultivation of penicillin.

Chaga preparations have a stimulating and tonic effect on the body, have antibiotic properties against many microorganisms, cure gastritis, promote resorption malignant tumors in early stages development.

Yeast used for a range of industries Food Industry(obtaining beer, wine, etc.), they are nutritious in themselves, as they contain proteins, carbohydrates, fats, vitamins. Highest value for a person has Saccharomyces cerevisiae(baker's yeast). Yeast biomass is well absorbed by the human body, so yeast is specially grown for medicinal purposes. They are used in liquid form and in tablets.

Ergot is used as a source of alkaloids that cause contraction of smooth muscles used in gynecological practice.

Many mushrooms have valuable food and medicinal properties. The science of treating various diseases with mushrooms is called fungotherapy.

Spare parts: in eumycetes, glucose is stored in the form of alpha-glucan (close to glycogen), and in oomycetes in the form of beta-glucan (close to laminarin); trehalose oxaccharide; sugar alcohols; lipids (in the form of droplets of fat). Food(osmotrophic) is largely associated with plants, so fungi secrete enzymes for the destruction of pignin (pectinase, xylonase, cellobiase, amylase, lignase) and the destruction of ether bonds in cutin wax (cutylase).

Cleavage products enter the cells in three ways: 1. In a dissolved form (due to the turgor pressure of hyphae) 2. Passively (along the substance concentration gradient) 3. Actively (with the help of special protein transporter molecules) Environmental groups . According to trophic and topical features.

Topically: soil (red boletus (Leccinum aurantiacum), real camelina (Lactarius deliciosus)) and water (mukor - on the surface, camposporium - underwater structures)

The role of fungi in nature.

Degradation of polymers, Fixation of biophilic elements in the mushroom mass, Soil formation, Transformation of N, P, K, S and others into substances available for minimal plant nutrition, Creation of enzymes and biologically active substances in the soil, Destruction rocks and minerals, Formation of minerals, Participation in trophic chains, Regulation of the structure of the community and its abundance, Detoxification of pollutants (substances that can harm human health or the environment), symbiosis with plants and animals.

The value of mushrooms for humans.

Usage: Biotechnology, antibiotic producers, immunomodulator producers, anti-cancer, hormonal, anti-sclerotic, chitin - burn and wound healing, high adsorption, biopolymer destruction (enzymes), food industry (juice clarification), production of organic acids, phytohormone release, food and feed (yeast , basidium), biological pesticides, plant mycorrhization.

About 100,000 fungal species have been described so far, but some estimates may be as high as 1.5 million.

Systematics

Kingdom Mushrooms

Subkingdom Mushrooms

Subkingdom True Mushrooms (do not form motile cells at any stage of the life cycle)

Division Zygomycetes (belong to lower fungi)

Division Ascomycetes, or Marsupials

Department of Basidiomycetes

Department of Deuteromycetes (Imperfect fungi)

The body of the mushroom consists of long filaments - gif.

The hyphae grow apically (apically) and can branch to form a dense intertwined network -- mycelium, or mycelium.

Mycelium is located in the substrate (soil, wood, living organism) or on its surface.

The growth rate of mycelium depends on environmental conditions and can reach several centimeters per day.

In basidiomycetes, the mycelium is often perennial, in other fungi it is annual. Since the mycelium grows apically, its growth is centrifugal. The oldest part of the mycelium in the center gradually dies off, and the mycelium forms a ring. In addition, some fungi secrete substances that prevent plant growth (amensalism), and the vegetation cover forms rounded "bald spots".

Rice. "Witch Ring"

MYCELIUM TYPES

• non-cellular (non-septate) mycelium: formed by one multinucleated giant cell (for example, in zygomycetes);
• cellular (septated) mycelium: there are intercellular partitions (septa); cells are mononuclear or multinuclear. ATopenings may remain in cell partitions through which the cytoplasm and organelles (including nuclei) freely flow from cell to cell.

Ascomycetes dikaryotic mycelium(consists of binuclear cells).

Rice. Mycelium: 1 - unicellular (non-septate); 2 - multicellular (septate); 3 - dikaryotic (yeast).

Fruit bodies of basidiomycetes are formed by false tissue plectenchyma(pseudoparenchyma), consisting of densely intertwined hyphae of the mycelium. Plectenchyma, unlike ordinary parenchyma, is formed not by three-dimensionally dividing cells, but by strands of hyphae.

Hyphae are able to combine into long strands - rhizomorphs(ancient Greek - root-like form): the outer cells of the strand are denser and perform protective function, the inner more delicate cells perform a conductive function.

Rice. rhizomorphs

To endure adverse conditions, many mushrooms form dense rounded bodies formed by a plexus of hyphae - sclerotia(ancient Greek - solid). Outside, the sclerotia are covered with a hard dark shell that protects the inner light tender hyphae containing nutrients. Germinating, sclerotia give rise to mycelium; sometimes a fruiting body is immediately formed from them.

Rice. Ergot sclerotia

sclerotia

GIF FUNCTIONS (MYCELIUM):

Physiology of mushrooms

NUTRITION OF MUSHROOMS

According to the sources of organic substances used, fungi are divided into 4 groups.

Molecules of organic substances that make up living organisms and their residues cannot pass through the cell wall of fungi, so fungi secrete digestive enzymes into the substrate. These enzymes break down organic substances into low molecular weight compounds that the fungus can absorb on its surface (osmotrophic type of nutrition).This way it happens external digestion mushrooms.

• Predatory mushrooms: they actively catch prey with the help of modified hyphae (trapping loops, etc.).
• Symbiotic mushrooms: enter into symbiosis with various autotrophic organisms (lower and higher plants), receiving organic substances from them, and in return supply them with mineral nutrition.

SYMBIOSIS

• Mycorrhiza (mushroom root): symbiosis of fungi with the roots of seed plants.
  Since the area of ​​absorption of fungal hyphae is much larger than the area of ​​the absorption zone of roots, the plant receives much more minerals, which allows it to grow more actively. The plant, in turn, gives the fungus part of the carbohydrates, the products of photosynthesis.

Rice. Mycorrhiza

MUSHROOMS-SYMBIONTS

REPRODUCTION OF MUSHROOMS

Asexual reproduction:

• multicellular and unicellular parts of the mycelium
• spore formation
  endogenous spores (sporangiospores) are formed in sporangia
  exogenous spores (conidiospores = conidia) are produced in conidia
• budding (in yeast)

Rice. Mold sporulation: penicillium (a) and aspergillus (b) conidia; sporangiospores mucor (c)

sexual reproduction:

Real fungi do not have mobile cells, so the fusion of the cells of two individuals occurs through the growth and convergence of hyphae.

• fusion of gametes formed in gametangia (isogamy, heterogamy, oogamy);
• somatogamy: the fusion of two cells of the vegetative mycelium;
• gametangiogamy: the fusion of two sexual structures that are not differentiated into gametes;
• chologamy: cell fusion of unicellular fungi.

In addition to asexual sporulation, fungi also have sexual sporulation: the formation of spores by meiosis after the fusion of the genetic material of gametes or nuclei.

Rice. Mucor and its sporangium

REPRODUCTION OF MUCORA

Division Ascomycetes (Marsupials)

• About 30,000 species.
• Saprotrophic soil and mold fungi that settle on bread, vegetables and other products.
• Representatives: penicillium, yeast, morels, lines, ergot.
• Mycelium haploid, septate, branching. Through the pores, the cytoplasm and nuclei can pass into neighboring cells.
• Asexual reproduction using conidia or budding (yeast).
• During sexual reproduction, bags (asci) are formed, in which, during meiosis, haploid spores of sexual sporulation are formed.
  
  

YEAST

Yeasts are represented by a large number of species widely distributed in nature.

Unicellular or bicellular fungi, the vegetative body of which consists of mononuclear oval cells.

Different types of yeast can exist in diploid or haploid phases.

Yeasts are characterized by aerobic metabolism. They use various sugars, simple and polyhydric alcohols, organic acids and other substances as a carbon source.

The ability to ferment carbohydrates, breaking down glucose to form ethyl alcohol and carbon dioxide, served as the basis for the introduction of yeast into culture.

FROM6 H12 O6 С6Н12О6 → 2 FROM2 H5 OH 2C2H5OH + 2 FROMO2 2CO2

Yeast reproduces by budding and sexually.

Under favorable conditions yeast long time reproduce vegetatively by budding. The kidney arises at one end of the cell, begins to grow and separates from the mother cell. Often the daughter cell does not lose its connection with the mother cell and begins to form buds on its own. As a result, short chains of cells are formed. However, the connection between them is fragile, and when shaken, such chains break up into separate cells.

With a lack of nutrition and an excess of oxygen, sexual reproduction: Two cells fuse to form a diploid zygote. The zygote divides by meiosis to form a bag with 4 ascospores. The spores fuse to form a new diploid yeast cell.

Rice. Budding and sexual reproduction of yeast.

Outwardly, it resembles black-purple horns (sclerotia) protruding from the ear. They consist of densely intertwined hyphae.

Rice. Ergot

ERGO LIFE CYCLE

The binuclear mycelium forms fruit bodies, known as cap mushrooms.

Rice. The structure of cap mushrooms

On the underside of the cap is a spore-forming layer (hymenophore), on which special structures are formed - basidia.

To increase the surface of the hymenophore, the lower part of the cap is modified:

• at agaric the hymenophore has the form of radially divergent plates (russula, chanterelle, mushroom, champignon);
• in tubular fungi, the hymenophore has the form of tubes that are tightly adjacent to each other (boletus, boletus, butterdish, boletus).

Some fungi produce velum(= velum = cover) - a thin shell that protects in young age fruiting body of the fungus

• common veil: covering the entire fruiting body;
• private spathe: covers the lower surface of the cap with hymenophore.

With the growth of the fungus, the covers are torn and remain on the fruiting body in the form of rings and a rim. (volvo) on the stem, various scales and flaps covering the hat. The presence of bedspread remains and their features are important for the identification of fungi.

Rice. The rest of the veil (velum) on the fly agaric

When smut is damaged, instead of grain, black dust is obtained, which is the spores of the fungus. The ears become like charred firebrands. Infection by some species occurs at the flowering stage of cereals, when spores from the affected plant fall on the stigmas of the pistils of healthy plants. They germinate, the hyphae of the fungus penetrate the seed embryo, and a caryopsis is formed, outwardly healthy. The following year, by the time of flowering, sporulation of the fungus begins, flowers do not form, and the inflorescence takes on a charred appearance.

Rice. Smut

Polypores have a tubular perennial hymenophore, which annually grows from below.

A spore of a tinder fungus, hitting a wound in a tree, germinates into a mycelium and destroys the wood.

After a few years, perennial hoof-shaped or disc-shaped fruiting bodies are formed.

Tinder fungi secrete enzymes that break down wood and turn it into dust. Even after the death of a tree, the fungus continues to live on a dead substrate (as a saprotroph), annually producing a large number of spores and infecting healthy trees.

Therefore, dead trees and fruiting bodies of tinder fungi are recommended to be removed from the forest.

Rice. Pine fungus ( bordered tinder fungus) Rice. Trutovik scaly (variegated)

DEPARTMENT OF DEUTEROMYCETS, OR IMPERFECT FUNGI

• Deuteromycetes occupy a special position among fungi.
• They reproduce only asexually - conidia.
• Mycelium septate.
• Whole life cycle passes in the haploid stage, without a change in nuclear phases.

These fungi are "former" ascomycetes or, more rarely, basidiomycetes, which in the process of evolution have lost sexual sporulation for one reason or another. Thus, deuteromycetes represent a phylogenetically heterogeneous group.

mushroom meaning

• They are the main reducers in the decomposition of wood.
• They are food for many animal species, being the beginning of detrital food chains.
• Food product with high nutritional value.
• Yeast cultures are used in the food industry (bakery, brewing, etc.)
• Chemical raw materials for the production of citric acid and enzymes.
• Obtaining antibiotics (eg penicillin).

Botany The science that studies the plant kingdom (gr. nerd- grass, plant).

The ancient Greek scientist Theophrastus (III century BC), a student of Aristotle, created a system of botanical concepts, systematizing and summarizing all the knowledge of farmers and healers known at that time with his theoretical conclusions. It is Theophrastus who is considered the father of botany.

modern botany- the science of morphology, anatomy, physiology, ecology and taxonomy of plants

Signs of the Plant Kingdom

• eukaryotes;
• autotrophs (the process of photosynthesis);
• osmotrophic type of nutrition: the ability of cells to absorb only low molecular weight substances;
• unlimited growth;
• immobile lifestyle;
• reserve substance - starch (accumulates in plastids during photosynthesis);

Structural features of a plant cell (Fig. 1):

• cellulose cell wall
  The presence of a cell wall prevents the penetration of food particles and large molecules into the cell, so plant cells absorb only low molecular weight substances (osmotrophic type of nutrition). Plants absorb from environment water and carbon dioxide, for which the cell membrane is permeable, as well as mineral salts, for which cell membrane there are channels and carriers.
• plastids (chloroplasts, chromoplasts, leukoplasts);
• large central vacuole
  Bubble with cell sap, surrounded by a membrane - tonoplast. The tonoplast has a system of regulated carriers that are transferred to the vacuole various substances, maintaining the desired concentration of salts and acidity in the cytoplasm. In addition, the vacuole provides the necessary osmotic pressure in the cell, which leads to the appearance turgor- stress on the cell wall, which maintains the shape of the plant. The vacuole also serves as a storage site for nutrients and waste products of metabolism.
• There are no centrioles in the cell centers of plants.

Rice. 1. Plant cell

plant classification

The main ranks of plant taxa are distributed according to principle of hierarchy(subordination): larger taxa unite smaller ones.

For example:

Plant Kingdom

department Angiosperms

class Dicotyledonous

Asteraceae family

genus Chamomile

view Chamomile

life form- the appearance of the plant.

Basic life forms: tree, shrub, shrub and grass.

Wood- perennial plant with a large lignified trunk.

Bush- a plant with numerous medium-sized lignified trunks that live no more than 10 years.

Shrub- a low-growing perennial plant with lignified trunks, up to 40 cm high.

Herbs- herbaceous green shoots that die off annually. In biennial and perennial grasses, new shoots grow from wintering buds in spring.

higher and lower plants

Different groups of plants differ significantly in structure.

Lower plants do not have organs and tissues. Their body is thallus, or thallus. The lower plants are algae. Most of them live in aquatic environment. Under these conditions, they receive nutrition by absorbing substances from the entire surface of the body. All or most of cells of these plants are in the light and are capable of photosynthesis. Therefore, they do not need to quickly move substances around the body. The cells of these plants in most cases have the same type of structure.

Other photosynthetic organisms are also found in the aquatic environment. These are primarily cyanobacteria, which are sometimes called blue-green algae. These are prokaryotic organisms that are not plants.

Algae are often referred to as higher plants that live in water. In these cases, the term "algae" is used in an ecological rather than a systematic sense.

Higher plants have functionally different organs formed by specialized cells. Basically, they live on land. They receive water and mineral nutrition from the soil, and for photosynthesis they must rise above its surface, therefore, for such plants, the movement of substances between parts of the body (conductive tissue) and mechanical support and support for the ground-air environment (mechanical and integumentary tissues) are necessary.

The presence of specialized cells, tissues and organs allowed them to achieve large sizes and master a wide range of habitats. Many representatives of higher plants returned to the water for the second time. In fresh water bodies, they make up the bulk of aquatic vegetation.