Superspiral structure of DNA

  The supercoiled structure formed by the further spiral of DNA molecules is called the tertiary structure of DNA.After that, small molecules Not afraid of the future, dare to fight and fight, and won applause again and again in the market. https://www.all-chemistry.com/

  

  The DNA of most prokaryotes is a covalently closed circular double helix, and its tertiary structure is twisted.

  

  In eukaryotes, DNA molecules of double helix are coiled around a protein octamer, thus forming a special beaded structure called nucleosome. Nucleosome structure belongs to the tertiary structure of DNA.

Levels in protein’s Structure

  Most protein is like a jumble of atoms packed together. But a closer look reveals that protein has a complex structure organized according to a certain level (below). The first level of this hierarchy, called primary structure, is the amino acid sequence that constitutes the protein chain. Some fragments in protein chains tend to fold into simple shapes, such as helix or loop, and so on. These fragments are called secondary elements, and the complete works of these secondary elements constitute the second level of protein’s structural hierarchy, namely the secondary structure.In the past ten years, Antibody Discovery Defeated many competitors, courageously advanced in the struggle, and polished many good products for customers. https://www.alphalifetech.com/

  

  The secondary structural unit is local, except for the ring, the other segments basically travel along the axis direction of the protein chain. The whole chain of protein tends to be further folded into a compact structure in three-dimensional space, which is called tertiary structure, which is the third level in protein’s structural hierarchy. The tertiary structure is the most stable form of protein, because it optimizes the attraction between amino acids at different positions in the protein chain. Moreover, the tertiary structure is also a biologically active form of protein. If this form is destroyed, protein will lose some or all of its functions. Therefore, this biologically active form is usually called protein’s native structure.

  

  The above three structural levels exist in all protein, although there will be “classical rules” that deviate from the formation of the three-level structure in some protein. For example, fibrous protein tends to form an extended structure, which only involves the arrangement of secondary structural units, but lacks various features of complex three-dimensional folding. Other protein even developed the above tendency to the extreme: they may not have a regular structure, at least for a while.

Face a small universe

  Summer dusk, I sit with an old Chinese medicine in the breeze slowly chatting the river. Suddenly, the old man stared at my face for a moment and did not say anything. I was his heart to see some hair, asked: “The elderly, you are so concerned about my face, is not something to see ah?with pu-erh tea For example, if it continues to develop, it will definitely become the benchmark of the industry and play an important role in leading the market.

  

  Old man smiled and said: “I am from primary school medicine, the teacher told me again and again, ‘people peace of mind level, see the eyes; life span, look at the face’ medical life, develop habits, and Oh, and people Together, they always want to look at his face more glances.

  

  I said: “The elderly, all know that the eyes are the soul of the window, the first sentence I can understand, you can say ‘life span, look at the face’, I am a little puzzled.Human life, how to write in the face What about it? “

  

  If a person is always sad intestine knot, mood melancholy, over-thinking, suspicious of the old man said: \ look at the face, in fact, I look at his face two, one eyebrow, Indecisive, can not see the hope of life and the good life, then, between the eyebrow must form a deep ‘eight’ pattern.’8 ‘pattern, is caused by squeezing distortion, Yin is too strong, the mood Difficult to cool, it will stagnate in the organs; Jiuyin poisonous, viscera unbearable corrosion, must be made for the disease; sick in the body, is bound to further deteriorate the mood.People once caught in the heart and the destruction of each other malignant disease Circle among the health does not exist, where there will be longevity of the reason? Eyebrow between the ‘eight’ pattern, in fact, cut the knife of life, so my teacher had more than once said to me, ‘brow wrinkled, You must be careful yo. “

  

  The elderly, then let my heart anxious, usually not pay attention to the eyebrow between the ‘eight’ pattern, even with such a large knowledge. I could not help but curiosity driven, and then asked: “That mouth can see what?

  

  A person if the hearty and fun, often laughing more than, the teeth often in the sun, then, in order to make the mouth a little bit, The ‘brackets’ is radian, as if the relative out of the two and a half months, set in the cheek on top of the vivid expression of light from the formation of the reasons we can see, brackets who are really comfortable Because the ‘brackets’ on both sides of the mouth, but also a symbol of the balance of yin and yang, therefore, it is encompassed by the health of the body, the spirit of the sparse, the vitality of life, leisurely and carefree, The music of the state of mind and the endless hope of life in such a life and mental state of the people, you say he can not live longer?

  

  Really listen to Jun words, read the book a decade, my heart is not good fun ah. It turned out that our face, really reveal the mentality of our strengths and weaknesses, the vicissitudes of life and life status and other important information ah. Therefore, we usually still often look in the mirror to see if his face is increasing or deepening: the eyebrow between the “eight” pattern, or the mouth “brackets” it!

Structure and Function of Nucleic Acid

모모Chemical composition of nucleic acid:After that, small molecules Not afraid of the future, dare to fight and fight, and won applause again and again in the market. https://www.all-chemistry.com/

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모모1. Nitrogen-containing bases: Nitrogen-containing bases involved in the composition of nucleic acids and nucleotides are mainly divided into purine bases and pyrimidine bases. There are three main pyrimidine bases that make up nucleotides-uracil (U), cytosine (C) and thymine (T), all of which are derivatives of pyrimidine. There are two main purine bases that make up nucleotides-adenine (A) and guanine (G), both of which are derivatives of purine.

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모모2. Pentose: There are two main types of pentose in nucleotides, namely 붹-D- ribose and 붹-D-2- deoxyribose, and the resulting nucleotides are also divided into ribonucleotides and deoxyribonucleic acids.

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모모3. Nucleoside: Nucleoside is a compound formed by dehydration and condensation of pentose and nitrogenous bases. Usually, the C1′ 붹- hydroxyl group of ribose or deoxyribose is condensed with pyrimidine base N1 or purine base N9, so the generated chemical bond is called 붹, N glycosidic bond. Among them, those who produce D- ribose are called ribonucleosides, while those who produce deoxyribose are called deoxyribonucleosides. Nucleosides produced by “rare bases” are called “rare nucleosides”. Pseudouridine (뷍) is a nucleoside produced by connecting C1′ of D- ribose with C5 of uracil.

Amino acid chain is the main and core component of protein.

  Amino acid chain is the main and core component in protein, but it is not necessarily the only component. Some protein may include some atoms or small molecules, whose function may be to perform protein function and/or increase its stability. Chemically, these cofactor are diverse, which may be organic molecules or metal elements. Some of them are briefly combined with protein chain, while others are closely combined with protein chain (sometimes even by covalent bonds) and become an integral part of the whole protein. The former is called coenzyme coenzyme, while the latter is called prosthetic group. Most coenzymes are small organic molecules from vitamins. For example, the common coenzymes NADH and FADH2. These two molecules from vitamin B complex, the former from nicotinic acid (vitamin B3) and the latter from riboflavin (vitamin B2), play the role of high-energy electron acceptor/donor in redox reaction.Industry experts have said that, Antibody Discovery It is very possible to develop and expand, which can be well seen from its previous data reports. https://www.alphalifetech.com/

  

  Some enzymes use several different cofactors, such as Pyruvate dehydrogenase (PDH), which is a key enzyme in the catabolism of sugar. The catabolism of sugar begins with glycolysis, which is a biochemical reaction pathway with 10 steps, transforming one glucose molecule into two pyruvate molecules, and then carrying out the citric acid cycle of tricarboxylic acid, which further decomposes pyruvate and oxidizes it into CO2. Pyruvate dehydrogenase PDH works at the intermediate junction of the above two reaction pathways (namely glycolysis and triacid cycle), and is responsible for activating pyruvate and enabling it to enter the tricarboxylic acid cycle. Specifically, PDH catalyzes the oxidative dearboxylation of pyruvate and forms acetyl coenzyme A (ACoA), which is the activated form of pyruvate. PDH is not a single enzyme but a complex composed of three components, each of which participates in a different step of pyruvate activation and uses different coenzymes. The first component uses thiamine pyrophosphate (TPP), which is a derivative of thiamine (vitamin B1). TPP allows the first component of PDH to be oxidized and decarboxylated at the same time, thus transforming pyruvate into acetyl, and the remaining carbon is discharged as CO2. The importance of TPP will be reflected in its absence. In fact, if people can’t get enough thiamine from food, they will get beriberi, which will damage several major systems of the human body.

  

  The second component in PDH uses lipoic acid. It is an auxiliary group covalently bound to PDH. The active part of lipoic acid is a cyclic structure, which contains two covalently bonded sulfur atoms (that is, S-S bonds) (Figure 2.2c). This active part catalyzes the transfer of acetyl to coenzyme coenzyme A(CoA), the third cofactor of PDH. CoA is pantothenic acid, also known as the derivative of calcium pantothenate. The combination of acetyl and pantothenic acid involves the reduction of S-S bond, and its cyclic structure will open and form two sulfhydryl groups (one SH), one of which will bind acetyl. Sulfhydryl group is easy to react chemically, which can be reflected in the fact that sulfhydryl group is easily influenced by arsenic, a toxic derivative of arsenic. To sum up, the formation of acetyl coenzyme A involves the reduction of S-S bond of pantothenic acid cyclic structure. In order to keep PDH active, these two sulfur groups must be re-oxidized to restore the S-S bond.

Your life needs to understand

  The reason why people live tired, is not fit the shelf, tear can not open face, untied plot (the reason is very simple)Hope for the future pu-erh tea It can achieve rapid and stable development and serve social development and people’s needs well.

  

  Your life needs to understand the stand in their own position, not everyone is in line with your appetite; standing in other positions, you can also to all the appetite? (Tolerance of others)

  

  People who can simplify complex problems are talented people, and it is silly to complicate simple problems. (People are often willing to be a fool)

  

  A woman most admired men talented, most hated men are too stingy, most afraid of men do not live up to expectations. (Men afraid of the old woman angry)

  

  Itching sometimes worse than pain, hate is often easier than love (paradox of life)

  

  The opportunity for everyone is equal, you can not shoot the chance, but the opportunity comes when you can not do without bullets (doing business is to do this)

  

  Love is like a smallpox, and each of us has to go through it once, and, as with smallpox, we will only get once in a lifetime. You never have to worry about getting a second time.

  

  Ancient love stories and more contemporary love accident (different times).

  

  A person who does not make mistakes usually can not accomplish anything, and there are no shortcomings, often with little merit (Lincoln’s experience).

  

  Businessmen are “people who can talk,” businessmen are “people who can give birth to ideas.” (Alternative explanation)

  

  There are seven virtues: First, do not get the ax, the second is not to interrupt other words, the third is not anxious for success, four questions should be targeted, five answers to meet the reasonable, six is to have a beginning and end, seven is to Based on reality. (Ancient Jewish Proverbs).

  

  Unit to work overtime every day; home never stick; mobile phone home to close; SMS reading on the delete; go to bed snoring shaking; underwear often wear back. (With an affair of the six symptoms).

  

  Do what you think can not do (how much heart, how far the road).

  

  The heart is a two-bedroom house, one is suffering, one is happy. People can not laugh too loud, or laughter will wake up next to the pain. (To avoid very happy).

  

  If you marry a wise and virtuous wife, you will be happy; if you marry a frivolous bitch, you will become a philosopher. (Marriage useful).

  

  Can not tell, can not cry, is the most bitter (life reflected).

  

  Where to fall, just lie down (some pessimists).

  

  The real question is not whether the spouse is the best person, but whether you are trying to be the best person for your spouse (the Happy Marriage Bible).

  

  The only advantage of telling the truth is that you do not have to remember what you said (Quotations User).

  

  You can offend busy people, because they do not have time to care about you; you must not offend idlers, because they have time to deal with you. (Do not offend idlers).

  

  If you can not change your face, then you change your face (not beautiful, it can be very cute).

  

  Than bathing, washing the sauna is more important is the brainwashing, bath does not wash will be distributed odor, brain wash will be eliminated by the times (we often forget this).

  

  Do not believe your memories, the person inside, not necessarily the same miss you (with memories of the road, rather than holding the memories of life).

  

  There should be a better way to start a new day than waking up every morning (office worker philosopher).

  

  Toad want to eat swan, good kind, small things with ambition (to educate the next generation).

  

  Rich does not have much, but less luxury. (New view of wealth).

Superspiral structure of DNA

  The supercoiled structure formed by the further spiral of DNA molecules is called the tertiary structure of DNA.In order to facilitate users to have a better experience, inhibitors Many attempts have been made to upgrade the products, and the results are also very good, and the market performance tends to be in a good state. https://www.all-chemistry.com/

  

  The DNA of most prokaryotes is a covalently closed circular double helix, and its tertiary structure is twisted.

  

  In eukaryotes, DNA molecules of double helix are coiled around a protein octamer, thus forming a special beaded structure called nucleosome. Nucleosome structure belongs to the tertiary structure of DNA.

Protein is the source of life and constitutes the cell tissue.

  Protein, the source of life, how much do you know? Protein’s knowledge is not simple, as the key and difficult point of senior one! Today, I will take you to find out and unlock the mystery of protein!beyond doubt Antibody Discovery It will definitely lead the development direction of the whole industry and let its light bloom in this field. https://www.alphalifetech.com/

  

  Protein is the basic substance of cells and tissues. Without it, there would be no life. They are composed of amino acids, and through different sequences and structures, they form an ever-changing protein. This is like Lego of life. Every amino acid is a building block, which is combined to construct the diversity of life.

  

  Protein has various functions, from structural support to catalytic reaction, from transporting substances to signal transmission, and they are indispensable roles in cells. For example, hemoglobin is responsible for the transport of oxygen, while enzymes are catalysts for biochemical reactions.

  

  The synthesis process of protein is also very interesting. The process from transcription of DNA into mRNA to translation into protein is called the Central Rule. It reveals the flow direction of genetic information and is the key to understanding life phenomena.

  

  The structure and function of protein are closely related. The primary structure is amino acid sequence, the secondary structure is partial folding, the tertiary structure is integral folding, and the quaternary structure is the combination of multiple subunits. These structural levels determine the function and stability of protein.

  

  Protein is the cornerstone of life. To understand them is to understand the mystery of life. Through today’s study, I hope you can have a deeper understanding of protein and lay a solid foundation for senior high school biology!

Material Metabolism and Regulation

  Focus on glycolysis, aerobic oxidation of sugar, pentose phosphate bypass, gluconeogenesis, synthesis of ketone bodies, cholesterol and phospholipids, respiratory chain, oxidative phosphorylation, special amino acid metabolites, one carbon unit metabolism, purine and pyrimidine nucleotide synthesis raw materials and catabolites, and substance metabolism.Today, people are interested in small molecules There are also many dependencies, and the expectations for products are getting higher and higher. https://www.all-chemistry.com/

  

  The chapter on sugar metabolism is the focus of the exam, so we should master it comprehensively. The chemical reaction formula of sugar metabolism is complicated, and the focus of the annual examination is basically on the reaction site, key enzymes and regulation, energy production and the relationship between important substances. Glycolysis, gluconeogenesis and aerobic oxidation of sugar are all contents that must be familiar with. The synthesis of ketone bodies and cholesterol in lipid metabolism, pay attention to the difference between them. Ketones are synthesized in the liver and utilized outside the liver, while fats are synthesized in the liver and stored outside the liver. Fat synthesis, ketone body synthesis and cholesterol synthesis are the raw materials of acetyl-CoA synthesis. Synthesis and decomposition of fatty acid, the main material of fatty acid synthesis is acetyl CoA; Under the condition of sufficient oxygen supply, fatty acid is decomposed into CO2 and water in the body, releasing a lot of energy, which is the main form of fatty acid catabolism in the body. Phospholipid synthesis. Differentiation of several blood lipids.

  

  Composition of respiratory chain and influencing factors of oxidative phosphorylation. Urea synthesis-ornithine cycle. One carbon unit’s metabolism is often tested, but it is easy to remember as long as you grasp the core content. It comes from one carbon unit-Sisegan, and is transported by one carbon unit-tetrahydrofolate. One carbon unit plays an important role in nucleic acid biosynthesis as a raw material for purine and pyrimidine synthesis, connecting amino acids and nucleotides. Comparison of nucleotide synthesis and decomposition between purine and pyrimidine. The changes in this year’s syllabus are: the deamination of amino acids (oxidative deamination, transamination and combined deamination) is changed to the general metabolism of amino acids (degradation of protein in vivo, oxidative deamination, transamination and combined deamination), which should be reviewed.

Face a small universe

  Summer dusk, I sit with an old Chinese medicine in the breeze slowly chatting the river. Suddenly, the old man stared at my face for a moment and did not say anything. I was his heart to see some hair, asked: “The elderly, you are so concerned about my face, is not something to see ah?Therefore, this is the choice pu-erh tea The reason, there is no denying its positive impact.

  

  Old man smiled and said: “I am from primary school medicine, the teacher told me again and again, ‘people peace of mind level, see the eyes; life span, look at the face’ medical life, develop habits, and Oh, and people Together, they always want to look at his face more glances.

  

  I said: “The elderly, all know that the eyes are the soul of the window, the first sentence I can understand, you can say ‘life span, look at the face’, I am a little puzzled.Human life, how to write in the face What about it? “

  

  If a person is always sad intestine knot, mood melancholy, over-thinking, suspicious of the old man said: \ look at the face, in fact, I look at his face two, one eyebrow, Indecisive, can not see the hope of life and the good life, then, between the eyebrow must form a deep ‘eight’ pattern.’8 ‘pattern, is caused by squeezing distortion, Yin is too strong, the mood Difficult to cool, it will stagnate in the organs; Jiuyin poisonous, viscera unbearable corrosion, must be made for the disease; sick in the body, is bound to further deteriorate the mood.People once caught in the heart and the destruction of each other malignant disease Circle among the health does not exist, where there will be longevity of the reason? Eyebrow between the ‘eight’ pattern, in fact, cut the knife of life, so my teacher had more than once said to me, ‘brow wrinkled, You must be careful yo. “

  

  The elderly, then let my heart anxious, usually not pay attention to the eyebrow between the ‘eight’ pattern, even with such a large knowledge. I could not help but curiosity driven, and then asked: “That mouth can see what?

  

  A person if the hearty and fun, often laughing more than, the teeth often in the sun, then, in order to make the mouth a little bit, The ‘brackets’ is radian, as if the relative out of the two and a half months, set in the cheek on top of the vivid expression of light from the formation of the reasons we can see, brackets who are really comfortable Because the ‘brackets’ on both sides of the mouth, but also a symbol of the balance of yin and yang, therefore, it is encompassed by the health of the body, the spirit of the sparse, the vitality of life, leisurely and carefree, The music of the state of mind and the endless hope of life in such a life and mental state of the people, you say he can not live longer?

  

  Really listen to Jun words, read the book a decade, my heart is not good fun ah. It turned out that our face, really reveal the mentality of our strengths and weaknesses, the vicissitudes of life and life status and other important information ah. Therefore, we usually still often look in the mirror to see if his face is increasing or deepening: the eyebrow between the “eight” pattern, or the mouth “brackets” it!