The main building material of the human body. Proteins are the main building material of the cells and tissues of the body. Nitrogen balance - positive and negative

Cells - construction material body. Tissues, glands, systems and, finally, the body are composed of them.

Cells

Cells are different forms and sizes, but for all of them there is a general structure scheme.

The cell consists of protoplasm, a colorless, transparent jelly-like substance, consisting of 70% water and various organic and inorganic substances. Most cells consist of three main parts: the outer shell, called the membrane, the center - the nucleus and the semi-liquid layer - the cytoplasm.

The cell membrane is made up of fats and proteins; it is semipermeable, i.e. allows substances such as oxygen and carbon monoxide to pass through.
The nucleus consists of a special protoplasm called the nucleoplasm. The nucleus is often called the "information center" of the cell because it contains all the information about the growth, development and functioning of the cell in the form of DNA (deoxyribonucleic acid). DNA contains the material necessary for the development of chromosomes, which carry hereditary information from the mother cell to the daughter cell. Human cells have 46 chromosomes, 23 from each parent. The nucleus is surrounded by a membrane that separates it from other structures of the cell.
The cytoplasm contains many structures called organelles, or "small organs", which include: mitochondria, ribosomes, the Golgi apparatus, lysosomes, the endoplasmic reticulum and centrioles:

Mitochondria are spherical, elongated structures often referred to as "energy centers" because they provide the cell with the power it needs to produce energy.
Ribosomes are granular formations, a source of protein that a cell needs for growth and repair.
The Golgi apparatus consists of 4-8 interconnected sacs that produce, sort and deliver proteins to other parts of the cell for which they are a source of energy.
Lysosomes are spherical structures that produce substances to get rid of damaged or worn parts of the cell. They are the "purifiers" of the cell.
The endoplasmic reticulum is a network of channels through which substances are transported within the cell.
Centrioles are two thin cylindrical structures arranged at right angles. They are involved in the formation of new cells.

Cells do not exist on their own; they work in groups of similar cells - tissues.

fabrics

epithelial tissue

The walls and integuments of many organs and vessels consist of epithelial tissue; There are two types: simple and complex.

Simple epithelial tissue consists of a single layer of cells, which are of four types:

Squamous: flat cells lie scale-like, edge to edge, in a row, like tiled floor. Scaly cover is found in parts of the body that are little subject to wear and damage, such as the walls of the alveoli of the lungs in the respiratory system and the walls of the heart, blood and lymph vessels in the circulatory system.
Cuboid: cubic cells arranged in a row form the walls of some glands. This tissue allows fluid to pass through during secretion, such as when sweat is released from the sweat gland.
Columnar: A series of tall cells that form the walls of many organs in the digestive and urinary systems. Among the columnar cells are goblet cells, which produce a watery liquid - mucus.
Ciliated: A single layer of squamous, cuboidal, or columnar cells that have projections called cilia. All cilia continuously undulate in the same direction, which allows substances such as mucus or unwanted substances to move along them. The walls of organs are formed from such tissue. respiratory system and reproductive organs. 2. Complex epithelial tissue consists of many layers of cells and there are two main types.

Layered - many layers of squamous, cuboidal or columnar cells from which a protective layer is formed. Cells are either dry and hardened or moist and soft. In the first case, the cells are keratinized, i.e. they dried up, and the result was a fibrous protein - keratin. Soft cells are not keratinized. Examples of hard cells: top layer of skin, hair and nails. Covers from soft cells - the mucous membrane of the mouth and tongue.
Transitional - similar in structure to non-keratinized stratified epithelium, but the cells are larger and rounded. This makes the fabric elastic; from which organs such as bladder, that is, those that should be stretched.

Both simple and complex epithelium must be attached to the connective tissue. The junction of the two tissues is known as the inferior membrane.

Connective tissue

It comes in solid, semi-solid and liquid. There are 8 types of connective tissue: areolar, adipose, lymphatic, elastic, fibrous, cartilaginous, bone and blood.

Areolar tissue - semi-solid, permeable, located throughout the body, being a binder and support for other tissues. It consists of the protein fibers collagen, elastin and reticulin, which provide its strength, elasticity and strength.
Adipose tissue is semi-solid, present in the same place as areolar tissue, forming an insulating layer. subcutaneous layer which helps keep the body warm.
Lymphatic tissue is semi-solid, containing cells that protect the body by engulfing bacteria. Lymphatic tissue forms those organs that are responsible for controlling the health of the body.
Elastic fabric - semi-solid, is the basis of elastic fibers that can stretch and, if necessary, restore their shape. An example is the stomach.
Fibrous tissue is strong and hard, made up of connective fibers made from the protein collagen. From this tissue, tendons are formed that connect muscles and bones, and ligaments that connect bones to each other.
Cartilage is a hard tissue that provides connection and protection in the form of hyaline cartilage that connects bones to joints, fibrous cartilage that connects bones to the spine, and elastic cartilages of the ear.
Bone tissue is hard. It consists of a hard, dense compact layer of bone and a somewhat less dense spongy substance of bone, which together form the skeletal system.
Blood is a liquid substance composed of 55% plasma and 45% cells. Plasma makes up the bulk of the liquid mass of blood, and the cells in it perform protective and connective functions.

Muscle

Muscle tissue provides movement to the body. There are skeletal, visceral and cardiac types of muscle tissue.

Skeletal muscle tissue is striated. It is responsible for the conscious movement of the body, such as movement when walking.
Visceral muscle tissue is smooth. It is responsible for involuntary movements such as the movement of food through the digestive system.
Cardiac muscle tissue provides the pulsation of the heart - the heartbeat.

nervous tissue

Nervous tissue looks like bundles of fibers; it is composed of two types of cells: neurons and neuroglia. Neurons are long, sensitive cells that receive and respond to signals. Neuroglia support and protect neurons.

Organs and glands

tissue in the body different types combine to form organs and glands. Organs have a special structure and functions; they are composed of tissues of two or more kinds. Organs include the heart, lungs, liver, brain, and stomach. The glands are composed of epithelial tissue and produce special substances. There are two types of glands: endocrine and exocrine. Endocrine glands are called endocrine glands, because. they release the produced substances - hormones - directly into the blood. Exocrine (exocrine glands) - into the channels, for example, sweat from the corresponding glands through the corresponding channels reaches the surface of the skin.

Body systems

Groups of interconnected organs and glands that perform similar functions form the systems of the body. These include: integumentary, skeletal, muscular, respiratory (respiratory), circulatory (circulatory), digestive, genitourinary, nervous and endocrine.

organism

In the body, all systems work together to ensure human life.

reproduction

Meiosis: A new organism is formed by the fusion of a male sperm and a female egg. Both the egg and the sperm contain 23 chromosomes each, in a whole cell - twice as many. When fertilization occurs, the egg and sperm fuse to form a zygote that
46 chromosomes (23 from each parent). The zygote divides (mitosis) and an embryo, a fetus, and finally a person is formed. In the process of this development, cells acquire individual functions (some of them become muscular, others become bone, etc.).

Mitosis- simple cell division - continues throughout life. There are four stages of mitosis: prophase, metaphase, anaphase, and telophase.

During prophase, each of the two centrioles of the cell divides, while moving to opposite parts of the cell. At the same time, the chromosomes in the nucleus pair up and the nuclear membrane begins to break down.
During metaphase, the chromosomes are placed along the axis of the cell between the centrioles, at the same time the protective membrane of the nucleus disappears.
During anaphase, the centrioles continue to expand. Individual chromosomes begin to move in opposite directions, following the centrioles. The cytoplasm in the center of the cell narrows and the cell shrinks. The process of cell division is called cytokinesis.
During telophase, the cytoplasm continues to shrink until two identical daughter cells are produced. A new protective membrane is formed around the chromosomes, and each new cell has one pair of centrioles. Immediately after division, there are not enough organelles in the resulting daughter cells, but as they grow, called interphase, they are completed before the cells divide again.

The frequency of cell division depends on its type, for example, skin cells multiply faster than bone cells.

Selection

Waste substances are formed as a result of respiration and metabolism and must be removed from the cell. The process of their removal from the cell follows the same pattern as the absorption of nutrients.

Motion

Small hairs (cilia) of some cells move, and whole blood cells move throughout the body.

Sensitivity

Cells play a huge role in the formation of tissues, glands, organs and systems, which we will study in detail as we continue our journey through the body.

Possible violations

Diseases result from the destruction of cells. With the development of the disease, this is reflected in tissues, organs and systems and can affect the entire body.

Cells can be destroyed for a number of reasons: genetic (hereditary diseases), degenerative (during aging), dependent on environment, for example at too high temperatures, or chemical (poisoning).

Viruses can only exist in living cells, which they capture and multiply in, causing infections such as colds (herpes virus).
Bacteria can live outside the body and are divided into pathogenic and non-pathogenic. Pathogenic bacteria are harmful and cause diseases such as impetigo, while non-pathogenic bacteria are harmless: they keep the body healthy. Some of these bacteria live on the surface of the skin and protect it.
Fungi use other cells to live; they are also pathogenic and non-pathogenic. Pathogenic fungi are, for example, foot fungi. Some non-pathogenic fungi are used in the production of antibiotics, including penicillin.
Worms, insects and mites are pathogens. These include worms, fleas, lice, scabies mites.

Microbes are contagious, i.e. can be transmitted from person to person during infection. Infection can occur through personal contact, such as touching, or through contact with an infected instrument, such as a hairbrush. When the disease can manifest symptoms: inflammation, fever, swelling, allergic reactions and tumors.

Inflammation - redness, heat, swelling, pain, and loss of ability to function normally.
Fever - increased body temperature.
Edema is swelling resulting from excess fluid in the tissue.
A tumor is an abnormal growth of tissue. It can be benign (not dangerous) or malignant (may progress, leading to death).

Diseases can be classified into local and systemic, hereditary and acquired, acute and chronic.

Local - diseases in which a certain part or area of \u200b\u200bthe body is affected.
Systemic - diseases in which the whole body or several parts of it are affected.
Hereditary diseases are present at birth.
Acquired diseases develop after birth.
Acute - diseases that occur suddenly and quickly pass.
Chronic diseases are long-term.

Liquid

The human body is 75% water. Most of this water found in cells is called intracellular fluid. The rest of the water is found in the blood and mucus and is called the extracellular fluid. The amount of water in the body is related to the content of adipose tissue in it, as well as to gender and age. Fat cells do not contain water, so thin people have a higher percentage of water in their bodies than those with a large body fat. In addition, women usually have more adipose tissue than men. With age, the water content decreases (most of the water in the bodies of infants). Most of the water is provided by food and drink. Another source of water is dissimilation in the process of metabolism. The daily human need for water is about 1.5 liters, i.e. as much as the body loses in a day. Water leaves the body with urine, feces, sweat and breathing. If the body loses more water than it receives, dehydration occurs. The balance of water in the body is regulated by thirst. When the body is dehydrated, the mouth feels dry. The brain responds to this signal with thirst. There is a desire to drink to restore the balance of fluid in the body.

Relaxation

Every day there is a time when a person can sleep. Sleep is rest for the body and mind. During sleep, the body is partially conscious, most of its parts temporarily suspend their work. The body needs this time of complete rest to “recharge the batteries”. The need for sleep depends on age, occupation, lifestyle and stress level. It is also individual for each person and varies from 16 hours a day for infants to 5 for the elderly. Sleep comes in two phases: slow and fast. Slow-wave sleep is deep, dreamless, it makes up about 80% of all sleep. During REM sleep, we dream, usually three or four times a night, lasting up to an hour.

Activity

Just like sleep, the body needs activity to stay healthy. In the human body there are cells, tissues, organs and systems responsible for movement, some of them are controllable. If a person does not take advantage of this opportunity and prefers sedentary image life, controlled movements become limited. As a result of insufficient physical activity mental activity may decrease, and the phrase “if you don’t use it, you lose it” applies to both the body and the mind. The balance between rest and activity is different for different systems organism and will be discussed in the relevant chapters.

Air

Air is a mixture of atmospheric gases. It is approximately 78% nitrogen, 21% oxygen, and another 1% other gases, including carbon dioxide. In addition, the air contains a certain amount of moisture, impurities, dust, etc. When we breathe in, we consume air using approximately 4% of the oxygen contained in it. When oxygen is consumed, carbon dioxide is produced, so the air we exhale contains more carbon monoxide and less oxygen. The level of nitrogen in the air does not change. Oxygen is necessary to sustain life, without it all creatures would die in a matter of minutes. Other components of the air may be harmful to health. The level of air pollution varies; breathing contaminated air should be avoided whenever possible. For example, when breathing air containing tobacco smoke, passive smoking occurs, which can have a negative effect on the body. The art of breathing is something that is most often greatly underestimated. It will develop so that we can make the most of this natural ability.

Age

Aging is a progressive deterioration in the body's ability to respond to maintaining homeostasis. Cells are capable of self-reproducing by mitosis; it is believed that they are programmed with a certain time during which they reproduce. This is confirmed by the gradual slowdown and eventually the cessation of vital processes. Another factor that influences the aging process is the effect of free radicals. Free radicals are toxic substances that accompany energy metabolism. These include pollution, radiation, and some food. They harm certain cells because they don't affect their ability to absorb nutrients and get rid of waste products. So, aging causes noticeable changes in human anatomy and physiology. In this process of gradual deterioration, the body's propensity for disease increases, physical and emotional symptoms appear, which are difficult to fight.

Color

Color is a necessary part of life. Every cell needs light to survive, and that contains color. Plants need light to produce oxygen, which humans need to breathe. Radioactive solar energy provides nourishment that is essential to the physical, emotional and spiritual aspects of human life. Changes in light entail changes in the body. Thus, the rising of the sun awakens our body, while the sunset and the associated disappearance of light cause drowsiness. Light has both visible and invisible colors. About 40% of the sun's rays carry visible colors, which become so due to the difference in their frequencies and wavelengths. Visible colors include red, orange, yellow, green, cyan, indigo and violet - the colors of the rainbow. Combined, these colors form light.

Light enters the body through the skin and eyes. The eyes, irritated by light, give a signal to the brain, which interprets the colors. The skin feels different vibrations produced by different colors. This process is mostly subconscious, but it can be brought to a conscious level by training the perception of colors with hands and fingers, which is sometimes called "color healing".

A certain color can produce only one effect on the body, depending on its wavelength and frequency of vibration, in addition, different colors are associated with different parts of the body. We will take a closer look at them in the following chapters.

Knowledge

Knowing the terms of anatomy and physiology will help you get to know the human body better.

Anatomy refers to the structure, and there are special terms that denote anatomical concepts:

Front - located in front of the body
Rear - located in the back of the case
Lower - pertaining to the lower part of the body
Upper - located above
External - located outside the body
Internal - inside the body
Lying supine - overturned on the back, face up
Prone - placed face down
Deep - below the surface
Surface - lying near the surface
Longitudinal - located along the length
transverse - lying across
Midline - the center line of the body, from the top of the head to the toes
Median - located in the middle
Lateral - remote from the middle
Peripheral - as far as possible from attachment
Near - closest to the attachment

Physiology refers to functioning.

It uses the following terms:

Histology - cells and tissues
Dermatology - integumentary system
Osteology - skeletal system
Myology - muscular system
Cardiology - heart
Hematology - blood
Gastroenterology - digestive system
Gynecology - female reproductive system
Nephrology - urinary system
Neurology - nervous system
Endocrinology - excretory system

Special Care

Homeostasis is a state in which cells, tissues, organs, glands, organ systems work in harmony with themselves and with each other.

This collaboration provides best conditions for the health of individual cells, its maintenance is a necessary condition for the well-being of the whole organism. One of the main factors affecting homeostasis is stress. Stress can be external, such as temperature fluctuations, noise, lack of oxygen, etc., or internal: pain, excitement, fear, etc. The body itself fights against daily stresses, it has effective countermeasures for this. And yet you need to keep the situation under control so that there is no imbalance. A serious imbalance caused by excessive prolonged stress can undermine health.

Cosmetic and wellness treatments help the client realize the effect of stress, possibly in time, and further therapy and specialist advice prevent imbalances and help maintain homeostasis.

elements of living organisms are:
a) N, O, H, S; b) C, H, N, O; c) S, Fe, O, C; d) O, S,
H, Fe

c) only proteins;

d) only water, carbohydrates, proteins and
nucleic acids.
4. At what level of organization
there is a difference between organic and
inorganic world?
a) atomic, b) molecular, c) cellular.
5. Water is contained more in the cells: a)
embryo, b) a young person, c) an old man.
6. Water is the basis of life:
a) it can be in three states
(liquid, solid, gaseous);
b) is a solvent providing
both the influx of substances into the cell and the removal
from it metabolic products;
7. Substances that are highly soluble in water,
are called: a) hydrophilic, b) hydrophobic,
c) amphiphilic.
8. To hydrophobic cell compounds
relate:
a) lipids and amino acids;
b) lipids;

a) starch; b) deoxyribose; c) ribose; G)
glucose.
a) storage and structural;

d) structural and protective.
12. Proteins are biopolymers with monomers,
which are: a) nucleotides; b)
amino acids; c) nitrogenous bases. thirteen.
Amino acids are:
a) an amino group, b) a carboxyl group; v)
radical.
a) only amino acids

d) amino acids and sometimes molecules
carbohydrates
13. The structure of the protein molecule, which
determines the sequence
amino acid residues: a) primary; b)
secondary; c) tertiary; d) quaternary. thirteen.
The secondary structure of a protein is associated with:
b) spatial configuration
polypeptide chain
c) number and sequence
amino acid residues
d) spatial configuration
spiralized polypeptide chain A 14.
14. Protein secondary structure is maintained
connections:
a) only peptide;
b) only hydrogen;
d) hydrogen and peptide;
15. Least Strong Structural Protein
is an:
a) primary and secondary
b) secondary and ternary
c) tertiary and quaternary
d) Quaternary and secondary
16. Protein catalase performs in the cell
function;
a) contractile;
b) transport;
c) structural;
d) catholic.
17. In case of incomplete protein denaturation of the first
the structure is destroyed: a) primary;
b) secondary;
c) only tertiary;

a) nucleosides;
b) nucleotides;
c) amino acids;

b) only nitrogenous bases and residues
sugars;
c) only nitrogenous bases and residues
phosphoric acids;
d) residues of phosphoric acids, sugars and
nitrogenous bases.
20. The composition of DNA nucleotides is different
content apart:
a) only sugars;

d) sugars, nitrogenous bases and residues
phosphoric acids.
21. DNA nucleotides contain nitrogenous
grounds:

2) only nitrogenous bases and residues
sugars;
3) only nitrogenous bases and residues
phosphoric acids;
4) residues of phosphoric acids, sugars and
nitrogenous bases.
23. Molecules, during the oxidation of which
a lot of energy is released: a)
polysaccharides; b) fats; c) proteins; G)
monosaccharides.

The main functions of the cell nucleus are: a) DNA replication b) RNA transcription c) storage of genetic information d) regulation of metabolic processes

flowing in the cell e) lysis of nutrients

Test "Chemical composition of the cell." 1 option.

I. The most common elements in the cells of living organisms are:
a) N, O, H, S; b) C, H, N, O; c) S, Fe, O, C; d) O, S, H, Fe
2. Nitrogen as an element is part of:
a) only proteins and nucleic acids;
b) nucleic acids, proteins and ATP;
c) only proteins;
d) proteins, nucleic acids and lipids;
3. Hydrogen as an element is part of:
a) only water and some proteins
b) only water, carbohydrates and lipids
c) all organic compounds of the cell
d) only water, carbohydrates, proteins and nucleic acids.
4. At what level of organization is there no difference between the organic and inorganic world?
a) atomic, b) molecular, c) cellular. 5. Water is contained more in the cells of: a) an embryo, b) a young person, c) an old man.
6. Water is the basis of life:
a) it can be in three states (liquid, solid, gaseous);
b) is a solvent that provides both the influx of substances into the cell and the removal of metabolic products from it;
c) cools the surface during evaporation.
7. Substances that are highly soluble in water are called: a) hydrophilic, b) hydrophobic, c) amphiphilic.
8. Hydrophobic cell compounds include:
a) lipids and amino acids;
b) lipids;
c) lipids and mineral salts;
d) amino acids and mineral salts.
9. Carbohydrate monosaccharides include:
a) starch; b) glycogen; c) glucose; d) maltose.
10. Carbohydrate polysaccharides include:
a) starch; b) deoxyribose; c) ribose; d) glucose.
II. The main functions of fats in the cell:
a) storage and structural;
b) structural and energy;
c) energy and storage;
d) structural and protective.
12. Proteins are biopolymers with monomers, which are: a) nucleotides; b) amino acids; c) nitrogenous bases. 13. Amino acids differ:
a) an amino group, b) a carboxyl group; c) a radical.
12. The composition of protein molecules includes:
a) only amino acids
b) amino acids and sometimes metal ions
c) amino acids and sometimes lipid molecules
d) amino acids and sometimes carbohydrate molecules
13. The structure of a protein molecule, which is determined by the sequence of amino acid residues: a) primary; b) secondary; c) tertiary; d) quaternary. 13. The secondary structure of a protein is associated with:
a) spiralization of the polypeptide chain
b) the spatial configuration of the polypeptide chain
c) the number and sequence of amino acid residues
d) the spatial configuration of the spiralized polypeptide chain A 14. 14. The secondary structure of the protein is supported by bonds:
a) only peptide;
b) only hydrogen;
c) disulfide and hydrogen;
d) hydrogen and peptide;
15. The least durable structural protein is:
a) primary and secondary
b) secondary and ternary
c) tertiary and quaternary
d) Quaternary and secondary
16. The catalase protein performs a function in the cell;
a) contractile;
b) transport;
c) structural;
d) catholic.
17. In case of incomplete protein denaturation, the structure is destroyed first: a) primary;
b) secondary;
c) only tertiary;
d) Quaternary, sometimes tertiary.
18. Monomers of DNA molecules are:
a) nucleosides;
b) nucleotides;
c) amino acids;
19 DNA nucleotides are made up of:
a) only nitrogenous bases;
b) only nitrogenous bases and sugar residues;
c) only nitrogenous bases and phosphoric acid residues;
d) residues of phosphoric acids, sugars and nitrogenous bases.
20. The composition of DNA nucleotides differs from each other in the content of:
a) only sugars;
b) only nitrogenous bases;
c) sugars and nitrogenous bases;
d) sugars, nitrogenous bases and phosphoric acid residues.
21. DNA nucleotides contain nitrogenous bases:
a) cytosine, uracil, adenine, thymine;
b) thymine, cytosine, guanine, adenine;
c) thymine, uracil, adenine, guanine;
d) uracil, cytosine, adenine, thymine.
22. RNA nucleotides consist of:
1) only nitrogenous bases;
2) only nitrogenous bases and sugar residues;
3) only nitrogenous bases and phosphoric acid residues;
4) residues of phosphoric acids, sugars and nitrogenous bases.
23. Molecules, during the oxidation of which a lot of energy is released: a) polysaccharides; b) fats; c) proteins; d) monosaccharides.

Fill in the missing words in the text.
Proteins are complex organic compounds...
They are made up of monomers...
Amino acids are located in a protein molecule in a certain sequence, which determines its .... structure. "
The main biological function of proteins in the cell
Substances that are reaction products of the combination of glycerol and liquid fatty acids - ....
The monomer of the starch molecule is.....
The five-carbon sugar that makes up the DNA molecule is...

Free response questions.
1. What does the similarity in the structure of the cells of organisms of all kingdoms of living nature testify to?
2. Why do proteins come first in terms of their importance in the cell? 3. What underlies the ability of the DNA molecule to duplicate itself?

This is outstanding work! A lot of questions ... Help, please! I only put half in here. Answer please! Prokaryotes, unlike eukaryotes, have

Choose one answer: a. mitochondria and plastids b. plasma membrane c. nuclear substance without a shell d. many large lysosomes Participate in the intake and movement of substances in the cell Select one or more answers: a. endoplasmic reticulum b. ribosomes c. liquid part of the cytoplasm d. plasma membrane e. cell center centrioles Ribosomes are Select one answer: a. two membrane cylinders b. rounded membranous bodies c. microtubule complex d. two non-membrane subunits A plant cell, unlike an animal cell, has one answer: a. mitochondria b. plastids c. plasma membrane d. Golgi apparatus Large molecules of biopolymers enter the cell through the membrane Select one answer: a. by pinocytosis b. by osmosis c. by phagocytosis d. by diffusion When the tertiary and quaternary structure of the protein molecules in the cell cease to function Select one answer: a. enzymes b. carbohydrates c. ATP d. lipids Question text

What is the relationship between plastic and energy metabolism

Choose one answer: a. energy exchange supplies oxygen for plastic b. plastic exchange supplies organic matter for energy c. plastic exchange supplies ATP molecules for energy d. plastic metabolism supplies minerals for energy

How many ATP molecules are stored during glycolysis?

Choose one answer: a. 38 b. 36 c. 4 d. 2

In the reactions of the dark phase of photosynthesis involved

Choose one answer: a. molecular oxygen, chlorophyll and DNA b. carbon dioxide, ATP and NADPH2 c. water, hydrogen and tRNA d. carbon monoxide, atomic oxygen and NADP+

The similarity of chemosynthesis and photosynthesis is that in both processes

Choose one answer: a. solar energy is used to form organic matter b. the formation of organic substances uses the energy released during the oxidation of inorganic substances c. organic substances are formed from inorganic d. the same metabolic products are formed

Information about the sequence of amino acids in a protein molecule is rewritten in the nucleus from DNA molecule to molecule

Choose one answer: a. rRNA b. mRNA c. ATP d. tRNA Which sequence correctly reflects the way of realization of genetic information Choose one answer: a. trait --> protein --> mRNA --> gene --> DNA b. gene --> DNA --> trait --> protein c. gene --> mRNA --> protein --> trait d. mRNA --> gene --> protein --> trait

The totality of chemical reactions in a cell is called

Choose one answer: a. fermentation b. metabolism c. chemosynthesis d. photosynthesis

The biological meaning of heterotrophic nutrition is

Choose one answer: a. consumption of inorganic compounds b. synthesis of ADP and ATP c. obtaining building materials and energy for cells d. synthesis of organic compounds from inorganic

All living organisms in the process of life use energy, which is stored in organic substances created from inorganic

Choose one answer: a. plants b. animals c. mushrooms d. viruses

In the process of plastic exchange

Choose one answer: a. more complex carbohydrates are synthesized from less complex b. fats are converted to glycerol and fatty acids c. proteins are oxidized with the formation of carbon dioxide, water, nitrogen-containing substances d. release of energy and synthesis of ATP

The principle of complementarity underlies the interaction

Choose one answer: a. nucleotides and the formation of a double-stranded DNA molecule b. amino acids and the formation of the primary structure of the protein c. glucose and the formation of a cellulose polysaccharide molecule d. glycerol and fatty acids and the formation of a fat molecule

The importance of energy metabolism in cellular metabolism lies in the fact that it provides synthesis reactions

Choose one answer: a. nucleic acids b. vitamins c. enzymes d. ATP molecules

Enzymatic breakdown of glucose without the participation of oxygen is

Choose one answer: a. plastic exchange b. glycolysis c. preparatory stage exchange d. biological oxidation

The breakdown of lipids to glycerol and fatty acids occurs in

Choose one answer: a. oxygen stage of energy metabolism b. the process of glycolysis c. the course of plastic exchange d. preparatory stage of energy metabolism

As in any other scientific field, in cell biology there are some postulates, which at one fine moment turn out to be not postulates at all, but just theorems. This happened, for example, with stem cells and scientists' ideas about what these cells are capable of.

The biotech company Genzyme has made a very high-profile -- and so far controversial -- claim that there are far fewer different types of stem cells in the adult human body than previously thought.

More precisely, Genzyme claims that the two most promising stem cell types for the treatment of all complex diseases are, in fact, one and the same.

Now some details.

Stem cells are cells that can transform into various types of biological tissues in the body. In other words, such cells are the main "building material" for the formation and regeneration of the body.

For a long time, the scientific world assumed that only embryonic stem cells were capable of creating any type of tissue. As for their close relatives present in the body of an adult, their capabilities are limited only to certain types of tissues - within the limits of their cellular specialization.

Embryonic stem cells can form any type of tissue, while the potential of adult stem cells has long been considered limited.

Naturally, stem cells derived from the human body can be used to treat diseases associated with severe tissue damage - including some heart ailments and brain diseases.

In this regard, at some point, the term "therapeutic cloning" appeared - that is, cloning aimed at obtaining these precious stem cells from embryos (10 days old) for subsequent cultivation, roughly speaking, biological "patches" for a damaged organism .

Alas, obtaining these cells would inevitably entail the destruction of the embryo. As it is easy to understand, these plans immediately ran into fierce resistance from the opponents of cloning as such, and in general from all those who believe that human life is not something that is a toy.

From the point of view of all Christian churches, for example, a person's life begins at the moment of conception, not birth from the womb. In other words, there is not much difference between the destruction of an embryo - a stem cell donor, abortion and "ordinary" murder for religious people.

Therefore, scientists have been looking for ways to obtain stem cells from other sources.

As already mentioned, for a long time it was believed that stem cells present in an adult organism are not universal, and are capable of producing only some types of living tissue specific to a given cell type.

Gradually, however, it became clear that the same cells can form several types of tissues at once.

And in 2002, a certain Catherine Verfaillie (Catherine Verfaillie) from the University of Minnesota (University of Minnesota), announced the discovery of a certain universal type of adult stem cells - (multipotent adult progenitor cells - MAPC).

Another "promising" type of stem cell appears to be mesenchymal stem cells (MSCs), discovered by the biotech company Osiris Therapeutics.

Yes, it was also quite a significant discovery.

Now, big biotech company Genzyme (a giant, as New Scientist dubbed it) claims that MSC and MAPC are one and the same.

How can this be, you ask? It's very simple, says Dr. Ross Tubo of Genzyme. In his opinion, different scientific institutions (in this case, the University of Massachusetts and Osiris) simply used different equipment - that's why the results of their MSC and MAPC studies turned out to be "so different from each other."

This became clear when Genzyme staff began to study the results obtained by other scientists. So Teubo's team set out to develop a standard way of assessing the potential of adult stem cells.

But first, fragments of bone marrow tissue were taken from a number of volunteers, and, following the methods of Osiris, Dr. Werfely and others, stem cells were obtained from it. As it turned out, each time on the surface of the received different ways cells, the same 12 proteins were observed. Moreover, regardless of the method of obtaining cells, they behaved the same way when the process of transformation into nervous or cartilage tissue was initiated.

Based on these indicators, Tubo concluded that we are talking about the same cells.

There is one more “but”: the technology for obtaining MAPC implies that the grown cells from the bone marrow must be at a great distance from each other.

Tubo's team didn't achieve anything this way, so the cell density they grew was very high...

Therefore, according to the employees of Athersys, which licensed the technology for obtaining MAPC from bone marrow, Tubo actually received not MAPC, but MSC. Getting MAPC without deviating from the original technology is difficult, but possible, according to Athersys employees. And then these cells are very different from MSC.

Question 1. What is an organ?

An organ is a part of the body that performs specific functions. They have a specific shape and location.

Question 2. What is the fabric?

Question 3. What is the educational tissue of plants?

Educational tissues are also called meristems. This structure consists of small, multifaceted cells with thin walls. They are tightly closed to each other. Under a microscope, you can see that they have a large nucleus and many small vacuoles. A feature of this tissue is the ability of its cells to constantly divide. This is what ensures the constant growth of the plant.

Question 4. What are they intended for? different types cells? How are stem cells different?

Different types of cells are designed to perform different functions.

Stem cells are undifferentiated (immature) cells found in many species. multicellular organisms. Stem cells are capable of self-renewal, forming new stem cells, dividing through mitosis and differentiating into specialized cells, that is, turning into cells of various organs and tissues.

Question 5. What cells are combined into a tissue? What types of tissue does the human body consist of?

Cells that are similar in structure and perform a specific function are combined into a tissue. The human body consists of 4 types of tissues: epithelial, connective, muscle and nervous.

Question 6. Think about what types of tissues no organ can do without.

No organ can do without connective tissue. Fibrous connective tissue is present in all organs.

Question 7. What is the biological meaning of combining tissues into an organ?

Organs are formed from tissues - body parts that have a certain shape and structure are placed in a certain place in the body and are adapted to perform certain functions. The eyes, the brain, the heart, the kidneys, the liver are all organs. Each of them is formed by several types of tissues, but one of them always prevails, determining the main function of the organ. For example, the heart is mainly made up of muscle tissue, while the brain is made up of nervous tissue. All organs are permeated with blood vessels and nerves. Organs, interconnected and combined to perform a vital task, form physiological system organs.

Question 8. Why is the muscle layer in the stomach wall much thicker than in the intestinal wall?

The main function of the stomach is the digestion of food. The muscular membrane provides the peristalsis of the stomach, which makes it possible to achieve the rhythmic movement of food. Therefore, the muscle layer in the stomach is thicker than in the intestinal wall.

Question 1. What is fabric?

Tissue - a system of cells and intercellular substance, united by a common origin, structure and functions.

Question 2. What types of tissues are isolated in the human body?

The human body consists of 4 types of tissues: epithelial, connective, muscle and nervous.

Question 3. What is general structure organ?

Each organ has its own shape and certain place in the human body. Organs that perform common physiological functions are combined into an organ system. Organs are composed of various tissues - epithelial, connective, muscle. They also have nerve endings.

Question 4. Why does medicine consider the study of stem cells one of its most important tasks?

Stem cells are the basis for the birth of a person. They form the human body at the stage of pregnancy and after birth form it further. But the essence is different, or rather, in two alleged uses of stem cells: the regeneration of damaged organs (both internal and external) and the cure of diseases (so far predominantly cancer). Based on the regenerative functions of these cells, the scientists decided to use them for the above "operations". Animal experiments have shown the effectiveness of treatment with this method, but there is still one big task - the artificial production of these cells, because. get a large number of human is extremely problematic. At the moment, everything is on the synthesis of cells.

Question 5. Why is the section of the paragraph on the structure of tissues called "Strength in unity"?

This section is called so because only with the coordinated work of all organs can the body function as a whole.

Question 6. What is the biological meaning of the separation of organs from each other?

Separating organs from each other improves the functioning of each organ, as they have a separate space for their growth. Thus, the organs do not interfere with each other.

"Protein structure" - Links: Quaternary protein structure. Food protein. Hemoglobin (found in red blood cells). Losses to the external environment. Performing mechanical work. Hemoglobin + carbon dioxide (formed in the capillaries of the systemic circulation). Fish. Without proteins, the growth of plants, animals and humans is impossible. The structure of the protein.

"Squirrel and Strelka" - Belka and Strelka were one of the most adapted dogs-applicants. After some time, Strelka had puppies. Belka and Strelka lived to a ripe old age and died a natural death. Squirrel at the Museum of Cosmonautics. During their flight, Belka and Strelka covered a distance of 700 thousand km. All six puppies were healthy.

"Amino acids and proteins" - Something similar happens in proteins. Squirrels. Amino acid device. For example, reds are attracted to yellows. Recent set for different organisms different. Energy value of some products. Protein helps us digest food and fight disease. Amino acids. Proteins and amino acids.

"Proteins and their functions" - Chemical properties proteins. The concept of proteins. Energy function. catalytic role. Contractile proteins cause all movement. Blood vessels, tendons, and hair are built from proteins. Each protein has its own specific structure. Secondary structure Tertiary structure Quaternary structure.

"Protein biology" - Isoleucine. Rice. 2 Peptide bonds in protein structure. Classification of proteins. What is the reverse reaction of protein hydrolysis called? The structure of proteins. Toxins. Valin. transport proteins. What compounds are formed during the hydrolysis of proteins? 3. By function. Alanine. Hormones. 2. By structure. Theme of the lesson: "Proteins are the biopolymers of life."

"Organisms and cells" - Endoplasmic reticulum. hereditary diseases. It was discovered in 1945 by the English scientist K. Porter. Electron microscope. Mitochondria. This is how amoeba, ciliates, and other protozoa feed. Functions of the endoplasmic reticulum. SCHWANN Theodor (1810 - 1882). Found in every cell of all organisms. The pyrimidine base is complementary to the purine base.