The most common inorganic substance. The most common substance on earth. Common structural features of the cells of all organisms

Water* The most common inorganic compound in living organisms is water. Its content varies widely: in the cells of tooth enamel there is about 10% water, and in the cells of the developing embryo - more than 90%. On average, in a multicellular organism, water makes up about 80% of body weight.

The role of water in the cell is very important. Its functions are largely determined by its chemical nature. The dipole nature of the structure of molecules determines the ability of water to actively interact with various substances. Its molecules cause the breakdown of a number of water-soluble substances into cations and anions. As a result, the ions quickly enter into chemical reactions. Most chemical reactions involve interactions between water-soluble substances.

Thus, the polarity of molecules and the ability to form hydrogen bonds make water a good solvent for a huge number of inorganic and organic matter. In addition, as a solvent, water provides both the influx of substances into the cell and the removal of waste products from it, since most chemical compounds can penetrate the outer cell membrane only in dissolved form.

No less important and pure chemical role water. Under the influence of certain catalysts - enzymes - it enters into hydrolysis reactions, i.e. reactions in which OH" or NG groups of water are added to the free valences of various molecules. As a result, new substances with new properties are formed.

Water is, to a certain extent, a heat regulator; due to good thermal conductivity and high heat capacity of water, when temperature changes environment, the temperature inside the cell remains unchanged or its fluctuations are significantly less than in the surrounding cell -. environment.

Mineral salts. Most of the inorganic substances in the cell are in the form of salts, either dissociated into ions or in the solid state. Among the former, K + cations are of great importance. Na +, Ca 2+, which provide this most important property living organisms, like irritability. In the tissues of multicellular animals, calcium is part of the intercellular “cement”, which determines the adhesion of cells to each other and their ordered arrangement in the tissues. The buffering properties of the cell depend on the concentration of salts inside the cell.

amino acid molecules form bonds between acidic carbon and nitrogen main groups. Such bonds are called covalent, and in this case - peptide connections:

The combination of two amino acids into one molecule is called dipeptide, three amino acids - tripeptide etc., and a compound consisting of 20 or more amino acid residues - polypeptide.

Amino acids have a general structural plan, but differ from each other in the structure of the radical (R), which is very diverse. For example, the amino acid alanine has a simple radical - CH3, the cysteine ​​radical contains sulfur - CH 2 SH, other amino acids have more complex radicals.

Proteins isolated from living organisms of animals, plants and microorganisms include several hundred and sometimes thousands of combinations of 20 basic amino acids. The order of their alternation is very diverse, which makes it possible for the existence of a huge number of protein molecules that differ from each other. For example, for a protein consisting of only 20 amino acid residues, about 2x10 variants are theoretically possible, differing in the alternation of amino acids, and therefore in the properties of different protein molecules. The sequence of amino acids in a polypeptide chain is called primary structure of the protein.

However, a protein molecule in the form of a chain of amino acid residues sequentially connected to each other by peptide bonds is not yet capable of performing specific functions. This requires a higher structural organization. By forming hydrogen bonds between the residues of the carboxyl and amino groups of different amino acids, the protein molecule takes the form spirals (a- structure) or the sweet accordion layer (/?- structure). This is the secondary structure of the protein (Fig. 3.1, 3.2).

Buffering refers to the ability of a cell to maintain the slightly alkaline reaction of its contents at a constant level. Buffer solutions are characterized by the fact that the introduction or formation of small amounts of acid or alkali into them during the metabolic process does not affect the pH values ​​due to the formation of compounds with carbonates, phosphates or organic molecules. Inside the cell, buffering is provided mainly by the anions H2PO4. In the extracellular fluid and in the blood, the role of a buffer is played by H2CO3 and HCO3. Anions of weak acids and weak alkalis bind hydrogen ions (H) and hydroxyl ions (OH), due to which reaction inside the cells remain virtually unchanged.

Insoluble mineral salts, for example calcium phosphate, are part of the intercellular substance of bone tissue, in the shells of mollusks, ensuring the strength of these formations.

the most abundant substance on earth

Melted Ice

The most common liquid on earth

Transparent colorless liquid

. "It's not beer that kills people, it's people..."

. "Off a duck's back..."

. "Don't spill..."

. "Under a lying stone... it doesn't flow"

. "ash two O"

. “It lives in seas and rivers, but often flies across the sky, and when it gets bored of flying, it falls to the ground again” (riddle)

. “quiet... the shores are washing away” (last)

. “subtle matter” that found itself on the first step of the “ladder of nature”, built in the 18th century by the Swiss naturalist Charles Bonnet

You are life

65% of the human body

Without her, “neither here nor here”

There is no life without her

Most vodka

They usually hide the ends in it

The most important inorganic substance for us

Vodka without alcohol

Vodka without alcohol

Hydrogen+ oxygen

Second to water and copper pipes

Carbonated...

Hot and cold in the tap

Kills people, unlike beer

Destroyer of people (song)

Distilled...

Jewel in the Desert

Friends, don't spill...

They don’t pound it in a mortar

It waters the garden and vegetable garden

Liquid cradle of life

Liquid

Liquid without taste, color or odor

Liquid in the bath

The liquid that flows in empty speeches

Liquid that has leaked a lot

Liquid necessary for the existence of all living things

What is a snowflake made of?

It was in this drop that the Roman sages advised to look “if you want to know the world.”

What coolant is usually used to cool a boiling reactor?

The stone sharpens

Painting by Russian artist S. Chuikov "Live..."

Well...

Concrete component

Vodka component

There is too much in vodka, according to drunkards

The best remedy for thirst

Flowing from the tap

An insignificant component of vodka

Mineralka

Mineral in a bottle

Mineral, carbonated

Muddy after ice drift

We drink it and bathe in it

We drink it and enjoy it

Pour into a bucket or glass

Pour into a kettle to boil

Filler for baths and seas

A prerequisite for life

One of the most common substances in nature

It turns out that you can get out of it dry

Deuterium oxide or heavy...

It flows in empty speeches

It can flow or it can drip

It does not flow under a lying stone

The basis of all life on Earth

The basis of life

Fresh milk in the night lake

Partner of fire and copper pipes

Drinking union of two gases

Rain Flesh

Flesh of the sea

According to the French chemist Leonel, the molecule of this substance resembles a peach with two apricots attached to its sides

The herbal liqueur "Danzig Gold...", popular in Germany, contains tiny particles of gold leaf.

Fresh...

Fresh in the lake

Fresh in the pond

Fresh liquid in a pond

A transparent, colorless liquid that is a chemical compound of hydrogen and oxygen

Flow in Jacuzzi

Hide and seek for ends

Melted Ice

Fish habitat

Escaped from the bucket

Seventh liquid on jelly

Seventh on jelly

Liquefied ice

According to the Kazakh proverb, without flaw only God, without dirt - only she

Contents. sieve according to the saying

Contents of the clepsydra

Contents of the river and sea

Contents of the samovar

Salty in the sea

Salty moisture of the sea

Salty sea...

Rescue from thirst

This is the name for the linear part of the distance for one boat

Shower turnover

Faucet leaking

What fish "breathe"

Something that won't spoil true friendship

What they carry to the offended

What is poured from the tap

Outdated ancient constellation

Quenches thirst

Film by A. A. Rowe "Fire, ... and Copper Pipes"

A chemical substance without which neither a person nor an animal can survive long.

Chemical substance in the form of a clear liquid

Walks without legs, sleeves without arms, mouth without speech (riddle)

How to dilute alcohol

What in Taoism has become a symbol of the triumph of visible weakness over strength

What boils in a samovar

What measured time in the ancient clepsydra

Not boiling. tea without sugar and tea leaves

Partner of fire and copper pipes

Don't drink it off your face, as the saying goes.

Contents of the cistern

Biology test Chemical composition cells for 6th grade students with answers. The test consists of 2 options, each with 11 tasks.

1 option

1. The most common inorganic substance found in living organisms is

1) water
2) calcium salt
3) table salt
4) carbon dioxide

2. The main organic matter of a cell is

1) water
2) protein
3) starch
4) calcium salts

3. Sucrose, or beet sugar, which we eat every day is

1) protein
2) fat
3) carbohydrate
4) nucleic acid

4. The importance of fats in the seal's body is that they

1) form a skeleton
2) participate in muscle contraction
3) store hereditary information
4) protect against heat loss

5. The main importance of nucleic acids in the body is associated with

1) storage of hereditary information
2) energy production
3) oxygen transport
4) wood formation

6.

A. The composition of the chemical elements that form the cells of all living organisms is similar.
B. Only animal organisms are made up of cells.

1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect

7. Are the following statements true?

A. There are chemical elements that are found only in living organisms and are absent in inanimate nature.
B. Most chemical elements are found in the cell in the form of chemical compounds.

1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect

8. Are the following statements true?

A. Water helps remove harmful substances from the body.
B. The main function of carbohydrates in a cell is energy.

1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect

9. Look at the diagram. Indicate the chemical compound whose content in the cell is 70-80%.

1) water
2) proteins
3) carbon dioxide
4) mineral salt

10. Establish a correspondence between chemical compounds and the group of substances to which they belong.

Chemical compounds

1. Proteins
2. Fats
3. Water
4. Mineral salts

Group of substances

A. Organic substances
B. Inorganic substances

11.

Answer the questions.

1. Indicate the chemical elements that form the basis of the cell.
2. What is the importance of calcium salts in living nature?

Option 2

1. Most chemical reactions that occur in a cell require an environment

1) alcohol
2) water
3) air
4) fat

2. The most common salt in living organisms

1) magnesium salt
2) sodium salt
3) phosphorus salt
4) lithium salt

3. The starch contained in potato tubers is

1) protein
2) fat
3) carbohydrate
4) nucleic acid

4. The main source of substances in the cell is

1) proteins
2) carbohydrates
3) mineral salts
4) nucleic acids

5. The transmission of hereditary characteristics from parents to children is carried out

1) fats
2) carbohydrates
3) nucleic acids
4) mineral salts

6. Are the following statements true?

A. Living organisms are made up of cells.
B. The chemical element carbon is widespread in living nature.

1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect

7. Are the following statements true?

A. The percentage of different chemical elements in a cell is different.
B. Chemical elements found in living nature are widely distributed in inanimate nature.

1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect

8. Are the following statements true?

A. Proteins make up about half of all organic substances in the cell.
B. Fats are part of inanimate bodies.

1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect

9. The picture shows a mollusk shell. Identify the chemical compound that is part of the shell.

1) fats
2) proteins
3) calcium salts
4) nucleic acids

10. Establish a correspondence between chemical compounds and the group of substances to which they belong.

Chemical compounds

1. Carbohydrates
2. Water
3. Mineral salts
4. Nucleic acids

Group of substances

A. Organic substances
B. Inorganic substances

11. Analyze the tabular data.

Prevalence of chemical elements in inanimate nature

Answer the questions.

1. Are there chemical elements that are found only in living organisms?
2. Which one chemical element widespread in inanimate and living nature?

Answer to a biology test: Chemical composition of a cell
1 option
1-1, 2-2, 3-3, 4-4, 5-1, 6-1, 7-2, 8-3, 9-1
10-AABB
11.
1. O, C, H, N - together they make up 98% of the contents of the cell.
2. They are part of bone tissue and mollusk shells.
Option 2
1-2, 2-2, 3-3, 4-2, 5-3, 6-3, 7-3, 8-1, 9-3
10-ABBA
11.
1. No. Elements that are found in living nature are also found in inanimate nature.
2. Oxygen.

1. What external stimuli do protozoa react to (mechanical, chemical, light, sound)?
2. How does the slipper ciliate differ from the amoeba (presence of pseudopods, mouth, cilia, chloroplasts, two nuclei)?
3. What cell organelles perform the digestive function in protozoa (Golgi apparatus, ribosomes, lysosomes, mitochondria)?
4. What are the functions of mitochondria in protozoa (protein synthesis, ATP synthesis, food breakdown, respiration)?
5. What is the function of the small nucleus in the ciliate slipper (responsible for the processes of synthesis and growth, carries hereditary information, participates in the sexual process)?
6. What is the essence of the sexual process in the ciliate slipper (reproduction, exchange of hereditary information, growth)?
7. What protozoa have a mineral skeleton (amoebas, sporozoans, radiolarians, ciliates)?
8. Which protozoa are the most ancient on Earth (amoebas, flagellates, ciliates, ciliates)?
9. Without what could the amoeba die (without food, without water, without air, without algae)?
10. Where does food digestion occur in ciliates (in the vacuole, in the cell mouth, in the stomach, in the nucleus)?

2Bacterial cells have a nucleus.

3 "bacterion" means "rod".

4 Mushrooms are plants lacking chlorophyll.

5 Mycology is the science of mushrooms.

6Fungal cells have nuclei.

7Lichens are symbiont organisms.

8Algae are the oldest photosynthetic organisms on Earth.

9The body of algae is divided into vegetative organs.

10All mosses have roots.

11Rhizoids are a type of roots.

12Gametophyte is the sexual generation of plants.

13 Horsetail leaves are of stem origin.

14Ferns have no roots.

18The main characteristic of angiosperms is the presence of a seed.

19Flowering plants are capable of forming complex communities.

20The main feature of dicotyledonous plants is the presence of two cotyledons in the seed.
write + or -

carbon dioxide, water and mineral salts), the plant feeds. 3. In the fields, after harvesting, minerals absorbed by plants do not return to the soil. 4. In the forest, mineral salts absorbed by plants return to the soil with fallen leaves and needles. 5.The feeding of a plant with air is called aerial nutrition. 6.Using chlorophyll from carbon dioxide and water in the leaf, organic substances (sugar) are formed. 7. Autotrophs are organisms capable of independently synthesizing organic substances from inorganic ones. 8.Green plants absorb energy sunlight and convert it into the energy of chemical bonds. 9. The role of green plants is called cosmic because they receive the energy of sunlight from space. 10. The energy from sunlight received from space is stored by green plants in the form of carbohydrates, fats and proteins. 11.With the appearance of green plants on Earth, atmospheric oxygen was formed. 12. Oxygen is a substance necessary for photosynthesis and plant respiration. 13. Respiration is the breakdown of complex organic substances into simpler, inorganic ones, and the release of the energy of chemical bonds. 14. Water flow in a plant depends on the suction capacity of root hairs. 15. Metabolism is the nutrition and respiration of plants.