Onion scales useful properties. Laboratory work "microscopic structure of onion skin"

Source of material The structure of the cell on the example of an onion

Onion cell structure.
On the micropreparation, oblong cells are visible, tightly adhering to one another. Each cell has a dense transparent membrane with thinner areas - pores, which can be distinguished only when high magnification. The composition of plant cell membranes includes a special substance - cellulose, which gives them strength. Inside is a colorless viscous substance - the cytoplasm (from the Greek words "kitos" - a vessel and "plasma" - formation). With strong heating and freezing, it is destroyed, and then the cell dies.
In the cytoplasm there is a small dense nucleus, in which the nucleolus can be distinguished. Using an electron microscope, it was found that the cell nucleus has a very complex structure.
In almost all cells, especially in old ones, cavities are clearly visible - vacuoles (from Latin word"vacuum" - empty). They are filled with cell sap - water with sugars and other organic and inorganic substances dissolved in it. When cutting a ripe fruit or other juicy part of a plant, we damage the cells, and juice flows out of their vacuoles. Cell sap may contain dyes (pigments) that give blue, purple, raspberry color to petals and other parts of plants, as well as autumn leaves.

Preparation and examination of the preparation of onion scales under a microscope
1. Consider in the figure the sequence of preparation of the onion peel preparation.
2. Prepare the glass slide by wiping it thoroughly with gauze.
3. Pipette 1-2 drops of water onto a glass slide.
4. Using a dissecting needle, carefully remove a small piece of transparent skin from the inner surface of the onion scales. Place a piece of skin in a drop of water and flatten with the tip of a needle.
5. Cover the skin with a coverslip as shown.
6. View the prepared preparation at low magnification. Note which parts of the cell you see.
7. Stain the slide with iodine solution. To do this, put a drop of iodine solution on a glass slide. With the filter paper on the other hand, pull off the excess solution.
8. Examine the stained preparation. What changes have taken place?
9. View the preparation at high magnification. Find on it


a dark stripe surrounding the cell, shell; under it is a golden substance - the cytoplasm (it can occupy the entire cell or be near the walls). The nucleus is clearly visible in the cytoplasm. Find a vacuole with cell sap (it differs from the cytoplasm in color). 10. Draw 2-3 onion skin cells. Designate the membrane, cytoplasm, nucleus, vacuole with cell sap.
in the cytoplasm plant cell there are numerous small bodies - plastids. At high magnification, they are clearly visible. In the cells of different organs, the number of plastids is different.
Plants have plastids different colors: green, yellow or orange and colorless. In cells of the skin of onion scales, for example, plastids are colorless.
The color of certain parts of them depends on the color of plastids and on the dyes contained in the cell sap of various plants. So, the green color of the leaves is determined by plastids called chloroplasts (from the Greek words "chloros" - greenish and "plastos" - fashioned, created). Chloroplasts contain the green pigment chlorophyll (from the Greek words "chloros" and "phyll" - leaf).
Plastids in Elodea leaf cells
1. Prepare a preparation of elodea leaf cells. To do this, separate the leaf from the stem, put it in a drop of water on a glass slide and cover with a coverslip.
2. Examine the preparation under a microscope. Find chloroplasts in cells.
3. Sketch the structure of the Elodea leaf cell. Write captions for the drawing.
The color, shape and size of the cells of different plant organs are very diverse.


plant cell shapes.

The existence of cells was discovered by the Englishman Robert Hooke in 1665.
Examining a thin section of cork (cork oak bark) through a microscope designed by him, he counted up to 125 million pores or cells in one square inch (2.5 cm). In the core of the elder, the stems of various plants, R. Hooke found the same cells. He called them cells. Thus began the study of the cellular structure of plants, but it did not go easily. The cell nucleus was discovered only in 1831, and the cytoplasm - in 1846.

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Biology Grade 6

Topic #2 Cell structure plants.

Lesson 1(4): The structure and life of a plant cell.

Laboratory work No. 2 "Cellular structure of onion skin"

Purpose: to reveal the structural features of a plant cell.

Equipment: bulb, microscope, slide and coverslip, dissecting needle, tweezers, pipette, water. iodine solution, napkin.

Working process:

Stage 1: Micropreparation

Prepare glass slide, wipe it with gauze ..

Apply 1-2 drops of water on glass.

Dissecting needle remove. skin from the inner surface of the onion scales.

Put piece of skin into a drop of water and spread with the tip of the needle.

cover skin with a cover glass.

Stage 2: Microscopy at low magnification.

1 .Consider preparation under a microscopeat low magnification. Note which parts of the cell you see.

2. Analyze textand correlate with your image of onion cells.

"On the micropreparation, oblong cells are visible, tightly adhering to one another.

Each cell has a dense transparentshell with thinner sectionspores, which can only be seen at high magnification.

The composition of plant cell membranes includes a special substance - cellulose, which gives them strength.

Inside is a colorless viscous substance -cytoplasm (from the Greek words "kitos" - vessel and "plasma" - formation). With strong heating and freezing, it is destroyed, and then the cell dies.The cytoplasm contains a small densecore , in which the nucleolus can be distinguished. Using an electron microscope, it was found that the cell nucleus has a very complex structure.In almost all cells, especially in old ones, cavities are clearly visible -vacuoles (from the Latin word "vacuus" - empty). They are filled with cell sap - water with sugars dissolved in it. Cell sap may contain dyes (pigments) that give blue, violet, crimson color to petals and other parts of plants, as well as autumn leaves.

Stage 3: Staining the preparation with iodine solution. Microscopy at high magnification.

1 . Stain the slide with iodine solution. To do this, put a drop of iodine solution on a glass slide. With the filter paper on the other hand, pull off the excess solution.2. Examine the stained preparation. What changes have taken place?3. View the slide at high magnification. Find chloroplasts on it.

Stage 4: Registration of the results of the work. Formulation of conclusions.

1. Sketch a diagram of the structure of a plant cell and designate: the nucleus, cell wall, cytoplasm, chloroplasts, vacuole.

2. Do conclusions about the structural features of the plant cell.

Onion peel. Beneficial features onion peel. Slow down aging.

To have beautiful thick and shiny hair, without dandruff - rinse your head with a decoction of onion peel. Onion peel will give a beautiful shade to fair hair.

A decoction of onion peels is easy to prepare: pour a handful of onion peels with a glass of water, boil for 5-10 minutes and cool to a pleasant temperature. Using this decoction, you will give your hair a beautiful lively shine.

You can cook soup using onions in the husk. Not only does the soup acquire an appetizing shade, it becomes much healthier thanks to the onion peel. It is very useful to add a pinch of onion or garlic peel into the teapot when brewing black or green tea.

Useful properties of onion peel, which we simply throw away.

Onion peel contains substances that tone up cardiac activity, increase immunity, not to mention expectorant, laxative, diuretic, choleretic, antispasmodic, antiseptic, anticancer and many other properties.

Hypertension every day tea drinkers from onion peel, are saved from hypertension.

A decoction of onion peel helps to remove excess sodium and chlorine from the body, and this is very important for the cores.

Onion peel will help get rid of leg cramps. Put a pinch of onion peel in a glass of boiling water and let it brew for 10 minutes. Then take out the husk and drink the resulting golden drink at night.

Studies have shown that garlic and onion peels contain 4% of the antioxidant biflavonoid quercetinin.

Natural biologically active substance, belongs to the vitamin P group. Active substance- Quercetin.

Apples, along with onions, garlic and green tea, are considered the main source of quercetin. And since for one reason or another, most of us need quercetin in higher doses, we need to get it from all these sources and, if possible, daily. Quercetin is considered good antihistamine and recommend to people suffering different forms allergies, as well as a means of prevention cardiovascular diseases. People who consume a lot of quercetin have a significantly lower risk of heart attacks and strokes and the likelihood of blood clots. If you take a piece of garlic scales and look under a microscope, you can find cubic crystals of quercetin stacked in rows.

In onion scales, the crystals are needle-shaped, pale yellow, laid out in rows along the veins of the scales. It is very important. Since quercetin is an antioxidant, it is more effective in this crystalline form. This is the basis of its role as a biological clock. As long as it is active and does not let oxygen pass to the growth point of a clove of garlic or onion, they do not germinate. They are at rest. Therefore, a decoction of onion and garlic scales should not be stored for a long time. Better to use right away.

Of greatest interest is quercetin as an anticancer agent, not only preventive, but also therapeutic. According to some scientific research, it stops the development of leukemia and inhibits the growth of breast tumors.

The positive effects of antioxidants have been proven by many studies and many years. clinical trials. Antioxidants have vasodilating, antitumor, anti-inflammatory, bactericidal, immunostimulating and antiallergic effects.

The antiviral activity of quercetin has been proven, which allows it to be used for prevention and complex therapy a number of viral infections. At certain levels of entry into the blood, quercetin reduces the release rate of histamine and other biologically active substances. active substances from mast cells, basophils, neutrophils and macrophages, thereby providing an anti-inflammatory effect.

Quercetin also slows down the formation of many products that accompany inflammation, through participation in the metabolism of fatty acids, the formation of certain enzymes. As a result, the formation of leukotrienes, which have a 1000 times stronger inflammatory effect than histamine, and can provoke the development of bronchial asthma, is reduced. ulcerative colitis, row skin diseases, such as atopic dermatitis, psoriasis, etc.

The ability to effectively bind histamine and histamine-like substances allows the antioxidant to be successfully used in the complex therapy of various arthritis, rheumatism, systemic lupus erythematosus, ulcerative colitis, hay fever and others. allergic diseases. The antioxidant prevents the formation of ulcers and hemorrhages on the walls of the stomach and intestines caused by external stimuli; normalizes the functioning of the nervous, immune and endocrine systems.

pharmachologic effect

Quercetin reduces capillary permeability and increases the resistance of the vascular wall, dilates blood vessels, lowers the tone of smooth muscles, and has antispasmodic properties.

Quercetin is used:

Increased permeability and fragility of capillaries hypertension, atherosclerosis, rheumatism, hematological, infectious and other diseases; capillary damage during treatment with anticoagulants, arsenic, bismuth, thiocyanates; as an adjuvant and prophylactic vascular complications atherosclerosis (myocardial infarction, stroke, retinopathy), with radiotherapy and radiosurgical treatment of malignant neoplasms.

Quercetin is a means by which you will get rid of both your diseases and the causes that cause them.

Main action:

Antioxidant - quercetin protects cell membranes by blocking the action of the aldose reductase enzyme responsible for development late stages a range of diseases and free radicals exogenous and endogenous origin, inhibits the aging process of skin cells, cornea, myocardium.

Increasing the tone of blood vessels (veins, arteries, capillaries) - quercetin, having an antioxidant and membrane-stabilizing effect on connective tissue vessels, stabilizes cell membranes, reduces the permeability of their walls.

Antiallergic - quercetin prevents the production of histamine and serotonin (allergy mediators), reduces swelling in hay fever and other allergies.

Anti-atherosclerotic - quercetin is more effective than vitamin E in eliminating the potential threat to the heart from cholesterol. It protects low density lipoproteins from oxidation, reducing the likelihood of their accumulation in the walls of arteries and the entire vascular system. Regular consumption of quercetin will significantly reduce the risk of cardiovascular disease.

Cardioprotective - quercetin improves myocardial function, as it increases the energy supply of cardiomyocytes, due to the antioxidant effect and improves blood circulation, as it prevents blood clotting, reducing the likelihood of blood clots, inhibits the synthesis of thromboxane.

Hypotensive - quercetin normalizes blood pressure with neurocirculatory dystonia, with coronary disease heart, angina.

Immunostimulating - quercetin increases the activity of phagocytes, T- and B-lymphocytes, increases the production of antibodies, which reduces the manifestations secondary immunodeficiency, incidence of acute respiratory viral infections: facilitates adaptation to hypoxia in children who often suffer from acute respiratory viral infections.

Anti-inflammatory - quercetin blocks the lipoxygenase pathway of arachidonic acid metabolism, prevents the production of leukotrienes, reducing the risk of developing inflammatory processes. Quercetin prevents the formation of inflammatory substances in the body, causing pain, at rheumatoid arthritis, prick.

Regenerative - quercetin promotes accelerated healing of wounds in periodontal disease, erosive and ulcerative diseases of the mucous membrane oral cavity and upper divisions alimentary canal; purulent inflammatory diseases soft tissues caused by non-steroidal anti-inflammatory drugs; affects the processes of bone tissue remodeling.

Oncoprotective - quercetin, strengthening immune system and accelerating the production of detoxifying enzymes that rid the body of potential carcinogens, counteracts malignant cell growth in leukemia and breast cancer, colon, ovarian and endometrial cancer.

Combined treatment of inflammatory diseases, including arthrosis and arthritis;
burn disease and frostbite;
cataract;
cosmetic rejuvenation programs, wrinkle reduction.
strengthening immunity.
varicose veins veins.
to slow down the aging process.

onion peel good for the treatment of fungal diseases of the nails, for this you need to soar your feet in a strong solution of onion peel for 30-40 minutes.

onion peel strengthens the hair, it significantly improves the structure of the hair and can be used as a natural dye.

In almost every home, onions are the most important product in most dishes. Many people know that in the process of cooking some dishes it is beneficial to use the husk, which saturates with vitamins and gives an appetizing color to soups.

The beneficial properties of onion peel have made it especially popular and widely used in folk medicine. Many healing effects this product received scientific rationale and validation.

Today we will talk about the composition, harm and benefits of onion peel, as well as the use of the product for various purposes.

Onion peel is a good source of vitamins: groups B, C, E, PP, carotene, fiber, sulfur compounds, fructans, the antioxidant quercetin and other flavonoids.

Sulfur compounds in the composition of onion scales improve blood flow and heal the cardiovascular system. And fructans act as prebiotics, that is, they selectively stimulate growth and activity beneficial bacteria that inhabit the large intestine. About the healing power of quercetin - a little later.

Also available a large number of trace elements from the periodic table: calcium, phosphorus, magnesium, iodine and many others.

Healing effects

Such diversity useful substances explains the benefits of onion peel and its decoction for prevention and treatment cancers. Other therapeutic effects:

• laxative;
• tonic;
• choleretic;
• anesthetic;
• antispasmodic;
• expectorant;
• anti-cancer;
• antiseptic, etc.

A decoction of onion peel does an excellent job of removing sodium and chloride salts from the body, which has a positive effect on the condition of people with diseases of the cardiovascular system.

For those who regularly suffer from pain in lower limbs after a hard day at work, the compounds contained in the husk will also help. Since the main cause of such pain is salt deposits.

The key ingredient in the product is quercetin, classified as a vitamin of a fairly large group P (includes about 150 bioflavonoids).

It has primarily anti-allergic and antihistamine effect. It is recommended for taking cores, as it is a prophylactic against stroke, heart attack and blood clots. Relieves depression and nervous tension.

The medical sector is conducting a series of studies on quercetin with the aim of unlocking its therapeutic potential, in particular the anti-cancer effect on the body.

Much attention is paid to the peel of onion heads as an excellent tool for stimulating the immune system. Surely you have repeatedly heard the phrase: "Eat onions and garlic - and you are not afraid of any flu." There is an element of truth in the statement.

On this medicinal properties onion "fur coats" do not end. It can be noted a good effect on the following groups of patients:

• allergy sufferers;
• asthmatics;
• diabetics;
• with kidney disease(jade, etc.);
• with hemorrhoids (the product is used for baths and lotions);
• problems of the urinary system (including cystitis);
• with stomatitis and other infections of the oral cavity;
• with fungal skin lesions and corns.

Benefits for women

Additionally, for women, the benefits of onion scales are the analgesic effect during menstruation, reducing the intensity of symptoms of premenstrual syndrome and menopause.

The effectiveness of this herbal remedy has also been proven for amenorrhea (absence of menstruation in women of reproductive age).

A decoction of the husk has a wonderful effect on hairline head, nourishes and improves the physical characteristics of each hair.

Precautionary measures

When taken intensively medical purposes decoction of onion peel can be harmful to health. The remedy, surprisingly, has few contraindications, despite the extremely powerful composition.

Application is not allowed when high level blood clotting, since quercetin thickens the blood and can aggravate the patient's condition.

You have to understand what it is herbal remedy does not provide guarantees and is not a panacea. Therefore, it should only be used as an adjunct to medicines prescribed by the attending physician.

onion vs garlic

Not only onion is a supplier of nutrients, but also its closest relative - garlic. considered more effective in the treatment of diseases that respond to high doses of quercetin. In particular, it does a better job of inferring heavy metals, cholesterol and radiation from the body.

In the absence of contraindications, the husks of both food crops can be used for medical purposes - together or separately. In many cases, these tools are interchangeable.

But garlic husks have an order of magnitude more contraindications. It cannot be used:

• children under 12;
• diabetics;
• with poor metabolism;
• under reduced pressure;
• with gastric ulcers and other diseases of the gastrointestinal tract.

Traditional medicine recipes

Given the historical age of the onion, a huge number of recipes have accumulated among the people. Consider the most popular of them.

Tincture from atherosclerosis

With atherosclerosis, it is necessary to use 20 drops 3 times a day alcohol tincture dissolved in 1 tbsp. l. sunflower oil, half an hour before a meal.

This tincture heals fungal infections nails.

The preparation process is quite simple: chopped onion peel is insisted on alcohol or vodka (in a ratio of 1: 7) for 1 week, after which it is poured into a dark glass container.

Oil for edema and varicose veins

The benefits of creams and oils with onion peel are undeniable. They can be applied to the skin or added to bath water.

Mix the grated husk with olive or grape seed oil (2 tablespoons). Further, the resulting composition is insisted for 10 days. Store in the refrigerator for 3 months.

Hair infusion

The product is an excellent strengthening preparation for hair, which causes an improvement in their characteristics and active growth. The resulting infusion is missing bad smell onion, so you can use it as often as needed.

For cooking, onion peel is poured with warm boiled water in a ratio of 1: 2 and tightly corked. Insist this mixture for 10 hours.

Hair infusion, as well as a classic decoction, is used to wash your hair for 2-3 weeks. In addition to accelerating hair growth, this remedy effectively fights seborrhea, preventing the appearance of dandruff.

onion tea

Don't want to waste time decoction? Then make some tea. Just place a small amount of washed husk in a special tea strainer and pour boiling water over it. This is perhaps the most easy way application, preserving the maximum amount of useful substances of the original product.

For muscle cramps, it is recommended to drink a cup of onion tea before bed. This drink will also help the cores. In the case of regular intake, the strengthening of the heart muscle, the cleansing of the vascular walls from atherosclerotic plaques and other cardiological benefits are guaranteed.

Recently, a Japanese firm launched a "Health Tea" containing fermented onion skins with a high concentration of quercetin. In addition to the husks, the tea contains 9 other healthy herbal ingredients, including green tea and turmeric.

Decoction of stomatitis and periodontal disease

1. 3 tsp boil pre-washed and dried husks in a small amount of water
2. Let stand for 7-8 hours.
3. Strain the decoction and use as a rinse several times a day.

Application in cosmetology

1. Natural dye, actively used for dyeing hair and obtaining a beautiful golden sheen. For this, 2 tbsp. l. the husks are boiled for 10 minutes in water. And the resulting liquid is used to wash the hair.
2. Works great with acne. In addition to eliminating foci of inflammation on the skin of the face, it creates the effect of prolonged action. As a result, improved general state epidermis and is restored normal condition sebaceous glands.
3. Fights boils and various types dermatitis. Importantly, a decoction of the husk successfully copes with itching, relieving the patient from discomfort.

Onion peel is an excellent remedy against many diseases, both superficial and localized in internal organs. The availability and ease of preparation of medicinal recipes also speak in favor of this remedy.