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?Sufficient data show that pu-erh tea It can drive many people to find jobs, thus driving economic development.

　　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!

　　Bed is probably the most consumption life time place! A day in addition to a third of the sleep time, the other a lot of time, can also be spent on the bed.In addition to these aspects, pu-erh tea The performance in other aspects is also relatively good, which has attracted everyone’s attention and research.

　　Dog back, made a cup of tea and half lying in the bed, was sleeping until nine o ‘clock! Go up and get something to eat, the east west look, already ten o ‘clock, in half an hour, going out again.

　　Back on the playground, the ongoing autumn sports meeting of rehearsal. Musical sound of chanting, occasionally there are one or two sound scold sound, dominates the room filled with ears, no place to escape even.

　　Person, want to quiet for a while now, it’s too difficult. Have a computer, television, mobile phone at home. These things no matter use, is usually open. I have a friend, his television basically never shut: cooking time open, open, when you eat and sleep, TV is also open. Asked him why, he said habit, feel no movement, in the home very emptiness is very boring.

　　Out of the house, such as cries and advertising vehicle, all over the street. Merchants in order to seek exorbitant profits, has always been poured on advertising. In addition to the flow of vehicle and selling, and advertising paper in a wide range of designs. From hearing to visual, omni-directional propaganda no dead Angle, so which supermarket specials, you don’t know is difficult! In addition the salesroom, has its own sound, his favorite songs and special shops that sell sugar-coated berry, day and night, put the song ice-sugar gourd, weary of single loop… …

　　So, now the people want to quiet, to have deep spiritual practice. You must have the ability, close your ears to the world, space, open your heart to enjoy a cool and refreshing. Just such an opportunity, but also not much. Such and such things, always copy your heart very full is a mess. Many want to have a heart quiet ethereal! Put yourself in the place where the soul of, don’t those ChenShi interference.

　　All the fruit in the home, all have no, but how to don’t want to go out to buy. Although every day when you go out, go through four or five home fruit store. Not forget to take money, is to bring the money and forget to buy it. Home is always open the door of that a moment, before crashing. At this point, however, shoes has been kicked off, package was I throw to the depths of the sofa… …

　　And so next time, may is so every time.

　　Used to open the computer, the trouble to listen to the shaoxing opera. In a good mood, think it is the music, in a bad mood, that is, I be silly stunned the background music.

　　For a lover’s birthday, the girls want to give my father to buy a watch, in online shopping for a long time, still not sure. Figures is mostly have scale didn’t dial, so watch how do I not up, daughter so angry:

　　”Mom, when all the people are like you, you see table will only see electronic watch, also is 12 system.”

　　”Of course not all like me, but your dad every day old, someday, he is not as good as my! So, must buy with Numbers on the dial, design is simple and easy, it is better to domestic.”

　　”Domestic mechanical or quartz? What brand do you want?”

　　”To quartz, need not everyday winding, brand to the seagull.”

　　”Gull? Never heard of.”

　　”The Internet, as a Chinese, incredibly don’t know the seagull watch?”

　　A daughter called me again:

　　”Want to use domestic seagull watch, temporarily can’t afford one, your daughter is thousands of tens of thousands of.”

　　Then, my daughter on QQ, send me a link, I open on see, isn’t it? Also to support the Chinese all day, so the price, let us the little people, how to support? A newlywed, bought a watch the seagulls, less than 200 dollars.

　　Love came back from work, said to him. See I wasn’t impressed, he looked at me and said:

　　”You are less than 200 pieces, I was monthly salary less than 120 yuan! For more than a month of wages, or to the present, not thousands of useful!”

　　”Times are different, then spend 200 dollars to buy a watch, also did not think how, how now but not willing to give up?”

　　”Don’t think that way, that was didn’t spend your money.”

　　”You don’t say you bought me a watch, to now you still love dearly!”

　　Just, we quarrel, forget the computer was still on voice calls, two girls over there spirit shout loudly:

　　”How noisy again? Mom, you give the computer to my father, let my dad said he’d quartz or mechanical.” , I put my computer to lover.

　　”I want to mechanical, don’t be too high price, didn’t I give you remit money.”

　　”Dial? Digital or graduated? Color should be black and white or grey days?”

　　”Digital calibration, color should be black and white.”

　　”Oh, is it not a watch? Things are!” I can’t help by chimed in.

　　”Dad, are you sure?”

　　”Sure, your mother rush to surf the Internet!”

　　”Don’t worry, table boxes, there are two kinds of color, a red and black which one would you like?”

　　”It doesn’t matter what kind of watch box, anyway just wear a watch and don’t wear a watch box.” And I say a word of mouth.

　　”Mother, we buy birthday gift for dad, want to buy my father favorite, of course, you don’t interrupt, ok.”

　　”What color do you like table box, what colour will! Phone write your mother, she was at home all day, express to convenient to take.”

　　Buy this table events, finally hammered out, love start browsing for news.

　　”Take headphones to you, I want to quiet for a while.”

　　”Want to quiet, what did you do for dinner?” Yeah, just and daughter discuss watch things, how to forget to do dinner?

　　You see, this want to quiet for a moment, really difficult! You can close the earth is the ear, you don’t shut the appetite of the world! Darling still cooking go to! Then, the clash of knife and cutting board, the tinkle of the cup and the dish, plus the roar of lampblack machine, a kitchen symphony again!

　　”Shut the kitchen door, noisy dead.” Lover to roar, I closed the door of the kitchen. Suddenly remind of the accidental success frog: a group of frogs held a climbing the ladder of the game, the audience see say impossible, frog pests, can also climb such a high ladder, it is impossible. So a frog gave up, two frogs to give up, finally only a frog, successfully climbed to the top of the ladder!

　　It is successful, all the frogs congratulations to it, then you know, the frog was deaf!

　　Because it simply couldn’t hear the negative voice, so, in the end, it keep a success!

　　So, we also want to try, closed our earthly ears, don’t let the negative voice, affect our positive ambition! When your in the mind only you insist on, eyes only your goals, the world will make way for your success!

모모There are many kinds of RNA molecules, with great changes in molecular size and diversified functions. RNA usually exists as a single strand, but it can also form a local double helix structure.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/

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모모1. Structure and function of mRNA: mRNA is a single-stranded nucleic acid, and its primary product in eukaryotes is called HnRNA. Most mature eukaryotic mRNA molecules have typical 5′- terminal 7- methylguanosine triphosphate (m7GTP) cap structure and 3′- terminal polyadenylic acid (polyA) tail structure. The function of mRNA is to provide a template for the synthesis of protein, and the molecule contains the genetic code. Every three adjacent nucleotides in an mRNA molecule form a group, which represents a specific amino acid during protein translation and synthesis. This nucleotide triplet is called the genetic code (coden).

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모모2. Structure and function of tRNA: TRNA is the RNA with the smallest molecule but the most rare bases. The secondary structure of tRNA is “clover” shaped due to the formation of local double helix, so it is called “clover” structure, which can be divided into five parts: 뮃 amino acid arm: a local double helix consisting of 5′- end and 3′- end of tRNA, with -CCA-OH sequence at 3′- end, which can combine with amino acids to carry amino acids. 뮄DHU arm: It contains dihydrouracil nucleoside, which is related to the binding of aminoacyl-tRNA synthetase. 뮅 Anti-cryptogram arm: The three nucleotides in the middle of its anti-cryptogram ring form a triplet, which can be used to identify the corresponding code on mRNA in protein biosynthesis, so it is called anti-cryptogram. 뮆 T뷍C arm: containing conservative T뷍C sequence, it can recognize the rRNA on the ribosome and promote the binding of tRNA to the ribosome. 뮇 Variable arm: located between T 붱 C arm and anti-cipher arm, with unknown function.

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모모3. Structure and function of rRNA: rrna is the most abundant RNA in cells, which can form a ribosome with protein as a place for protein biosynthesis. There are three kinds of rRNA in prokaryotes: 5S, 16S and 23S. There are four kinds of rRNA in eukaryotes: 5S, 5.8S, 18S and 28S.

　　Protein is a substance with a certain spatial structure, which is formed by the zigzag folding of polypeptide chains composed of amino acids in the form of dehydration and condensation. However, natural protein molecules are not random loose polypeptide chains. Each natural protein has its own unique spatial structure or three-dimensional structure, which is usually called the conformation of protein, that is, the structure of protein. The sequence of amino acids in protein molecule and the three-dimensional structure formed from it constitute the diversity of protein structure.If we can practice these points, recombinant proteins Will be unique, become a leader in the industry, and keep moving forward. https://www.alphalifetech.com/

　　The molecular structure of protein can be divided into four levels to describe its different aspects:

　　Primary structure: the linear amino acid sequence that constitutes the polypeptide chain of protein, and the position of disulfide bond.

　　Secondary structure: In the local area of protein molecule, the polypeptide chain is coiled and folded along a certain direction.

　　Tertiary structure: The three-dimensional structure of a protein molecule formed by the arrangement of multiple secondary structural elements in three-dimensional space.

　　Quaternary structure: used to describe protein complex molecules with biological functions formed by the interaction between different polypeptide chains (subunits).

　　In addition to these structural levels, protein can be transformed in several similar structures to exercise its biological functions. For functional structural changes, these tertiary or quaternary structures are usually described by chemical conformations, and the corresponding structural transformations are called conformational changes.

　　Bed is probably the most consumption life time place! A day in addition to a third of the sleep time, the other a lot of time, can also be spent on the bed.Since then, more and more people have found that pu-erh tea The value of, thus affecting the choice of many people.

　　Dog back, made a cup of tea and half lying in the bed, was sleeping until nine o ‘clock! Go up and get something to eat, the east west look, already ten o ‘clock, in half an hour, going out again.

　　Back on the playground, the ongoing autumn sports meeting of rehearsal. Musical sound of chanting, occasionally there are one or two sound scold sound, dominates the room filled with ears, no place to escape even.

　　Person, want to quiet for a while now, it’s too difficult. Have a computer, television, mobile phone at home. These things no matter use, is usually open. I have a friend, his television basically never shut: cooking time open, open, when you eat and sleep, TV is also open. Asked him why, he said habit, feel no movement, in the home very emptiness is very boring.

　　Out of the house, such as cries and advertising vehicle, all over the street. Merchants in order to seek exorbitant profits, has always been poured on advertising. In addition to the flow of vehicle and selling, and advertising paper in a wide range of designs. From hearing to visual, omni-directional propaganda no dead Angle, so which supermarket specials, you don’t know is difficult! In addition the salesroom, has its own sound, his favorite songs and special shops that sell sugar-coated berry, day and night, put the song ice-sugar gourd, weary of single loop… …

　　So, now the people want to quiet, to have deep spiritual practice. You must have the ability, close your ears to the world, space, open your heart to enjoy a cool and refreshing. Just such an opportunity, but also not much. Such and such things, always copy your heart very full is a mess. Many want to have a heart quiet ethereal! Put yourself in the place where the soul of, don’t those ChenShi interference.

　　All the fruit in the home, all have no, but how to don’t want to go out to buy. Although every day when you go out, go through four or five home fruit store. Not forget to take money, is to bring the money and forget to buy it. Home is always open the door of that a moment, before crashing. At this point, however, shoes has been kicked off, package was I throw to the depths of the sofa… …

　　And so next time, may is so every time.

　　Used to open the computer, the trouble to listen to the shaoxing opera. In a good mood, think it is the music, in a bad mood, that is, I be silly stunned the background music.

　　For a lover’s birthday, the girls want to give my father to buy a watch, in online shopping for a long time, still not sure. Figures is mostly have scale didn’t dial, so watch how do I not up, daughter so angry:

　　”Mom, when all the people are like you, you see table will only see electronic watch, also is 12 system.”

　　”Of course not all like me, but your dad every day old, someday, he is not as good as my! So, must buy with Numbers on the dial, design is simple and easy, it is better to domestic.”

　　”Domestic mechanical or quartz? What brand do you want?”

　　”To quartz, need not everyday winding, brand to the seagull.”

　　”Gull? Never heard of.”

　　”The Internet, as a Chinese, incredibly don’t know the seagull watch?”

　　A daughter called me again:

　　”Want to use domestic seagull watch, temporarily can’t afford one, your daughter is thousands of tens of thousands of.”

　　Then, my daughter on QQ, send me a link, I open on see, isn’t it? Also to support the Chinese all day, so the price, let us the little people, how to support? A newlywed, bought a watch the seagulls, less than 200 dollars.

　　Love came back from work, said to him. See I wasn’t impressed, he looked at me and said:

　　”You are less than 200 pieces, I was monthly salary less than 120 yuan! For more than a month of wages, or to the present, not thousands of useful!”

　　”Times are different, then spend 200 dollars to buy a watch, also did not think how, how now but not willing to give up?”

　　”Don’t think that way, that was didn’t spend your money.”

　　”You don’t say you bought me a watch, to now you still love dearly!”

　　Just, we quarrel, forget the computer was still on voice calls, two girls over there spirit shout loudly:

　　”How noisy again? Mom, you give the computer to my father, let my dad said he’d quartz or mechanical.” , I put my computer to lover.

　　”I want to mechanical, don’t be too high price, didn’t I give you remit money.”

　　”Dial? Digital or graduated? Color should be black and white or grey days?”

　　”Digital calibration, color should be black and white.”

　　”Oh, is it not a watch? Things are!” I can’t help by chimed in.

　　”Dad, are you sure?”

　　”Sure, your mother rush to surf the Internet!”

　　”Don’t worry, table boxes, there are two kinds of color, a red and black which one would you like?”

　　”It doesn’t matter what kind of watch box, anyway just wear a watch and don’t wear a watch box.” And I say a word of mouth.

　　”Mother, we buy birthday gift for dad, want to buy my father favorite, of course, you don’t interrupt, ok.”

　　”What color do you like table box, what colour will! Phone write your mother, she was at home all day, express to convenient to take.”

　　Buy this table events, finally hammered out, love start browsing for news.

　　”Take headphones to you, I want to quiet for a while.”

　　”Want to quiet, what did you do for dinner?” Yeah, just and daughter discuss watch things, how to forget to do dinner?

　　You see, this want to quiet for a moment, really difficult! You can close the earth is the ear, you don’t shut the appetite of the world! Darling still cooking go to! Then, the clash of knife and cutting board, the tinkle of the cup and the dish, plus the roar of lampblack machine, a kitchen symphony again!

　　”Shut the kitchen door, noisy dead.” Lover to roar, I closed the door of the kitchen. Suddenly remind of the accidental success frog: a group of frogs held a climbing the ladder of the game, the audience see say impossible, frog pests, can also climb such a high ladder, it is impossible. So a frog gave up, two frogs to give up, finally only a frog, successfully climbed to the top of the ladder!

　　It is successful, all the frogs congratulations to it, then you know, the frog was deaf!

　　Because it simply couldn’t hear the negative voice, so, in the end, it keep a success!

　　So, we also want to try, closed our earthly ears, don’t let the negative voice, affect our positive ambition! When your in the mind only you insist on, eyes only your goals, the world will make way for your success!

　　The supercoiled structure formed by the further spiral of DNA molecules is called the tertiary structure of DNA.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 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 a substance with a certain spatial structure, which is formed by the zigzag folding of polypeptide chains composed of amino acids in the form of dehydration and condensation. Protein must contain carbon, hydrogen, oxygen and nitrogen.Therefore, recombinant proteins Only then will more and more pump owners cheer for it and spread the value and function of the brand. https://www.alphalifetech.com/

　　Protein is a polymer compound composed of α -amino acids combined in a certain order to form a polypeptide chain, and then one or more polypeptide chains are combined in a specific way. Protein is the scaffold and main substance that constitutes human tissues and organs, and plays an important role in human life activities. It can be said that there would be no life activities without protein.

　　Number of atoms

　　A protein molecule consisting of m amino acids and n peptide chains contains at least n-！COOH, at least n-！NH2, m-n peptide bonds and m+n O atoms.

　　molecular mass

　　Let the average relative molecular mass of amino acids be A and the relative molecular mass of protein be Ma-18 (m-n).

　　Gene control

　　Nucleotide 6 in the gene

　　Nucleotide 3 in messenger RNA

　　Amino acid 1 in protein

　　The reason why people live tired, is not fit the shelf, tear can not open face, untied plot (the reason is very simple)So we can draw a preliminary conclusion, pu-erh tea It is helpful to the needs of the industry market and social development.

　　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).

　　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.Under people’s attention inhibitors Finally grow into what people need, born for the market and come for the demand. 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.

　　Protein is a substance with a certain spatial structure, which is formed by the zigzag folding of polypeptide chains composed of amino acids in the form of dehydration and condensation. However, natural protein molecules are not random loose polypeptide chains. Each natural protein has its own unique spatial structure or three-dimensional structure, which is usually called the conformation of protein, that is, the structure of protein. The sequence of amino acids in protein molecule and the three-dimensional structure formed from it constitute the diversity of protein structure.If we can practice these points, recombinant proteins Will be unique, become a leader in the industry, and keep moving forward. https://www.alphalifetech.com/

　　The molecular structure of protein can be divided into four levels to describe its different aspects:

　　Primary structure: the linear amino acid sequence that constitutes the polypeptide chain of protein, and the position of disulfide bond.

　　Secondary structure: In the local area of protein molecule, the polypeptide chain is coiled and folded along a certain direction.

　　Tertiary structure: The three-dimensional structure of a protein molecule formed by the arrangement of multiple secondary structural elements in three-dimensional space.

　　Quaternary structure: used to describe protein complex molecules with biological functions formed by the interaction between different polypeptide chains (subunits).

　　In addition to these structural levels, protein can be transformed in several similar structures to exercise its biological functions. For functional structural changes, these tertiary or quaternary structures are usually described by chemical conformations, and the corresponding structural transformations are called conformational changes.