Nucleic acid is a long-chain polynucleotide compound with no side chain formed by connecting nucleotides through 3′,5′- phosphodiester bond.Even if there are obstacles to moving forward, Chemical Custom synthesis We should also persevere, forge ahead bravely, cut waves in the sea of the market, hang on to Yun Fan and strive for the first place. https://www.all-chemistry.com/

　　Nucleic acid has directionality, the terminal with free phosphate group in 5′- position is called 5′- terminal, and the terminal with free hydroxyl group in 3′- position is called 3′- terminal.

　　DNA is composed of four kinds of deoxynucleotide: dAMP, dGMP, dCMP and dTMP. Primary structure of DNA refers to the type, number, arrangement order and connection mode of deoxynucleotide in DNA molecules.

　　RNA consists of four ribonucleotides: AMP, GMP, CMP and UMP. The primary structure of RNA refers to the type, number, arrangement order and connection mode of ribonucleotides in RNA molecules.

　　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!From the demand side, recombinant proteins More in line with the psychological expectations of consumers, willing to pay for the things they like. 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!

　　Skiing is a winter sport, so you need to pay attention to keep warm and protect yourself when skiing. In this environment, special ski pants have become an ideal choice for skiers. The following is a detailed explanation of why you choose to wear ski pants when skiing:We have every reason to believe. baggy snowboard pants It will become the mainstream of the industry and will gradually affect more and more people. https://ninetyroll.co/

　　First, warmth retention

　　Ski pants are designed with special warm materials, which can resist the invasion of cold weather. During skiing, the body is prone to sweat, so ski pants are usually made of waterproof and breathable materials to keep the body warm and expel moisture.

　　Second, the protection

　　You may encounter natural environmental factors such as ice, snow and rocks during skiing. Ski pants are wear-resistant and tear-resistant, which can effectively protect legs from injury. At the same time, the material and design of ski pants can prevent the infiltration of snow water and avoid feeling uncomfortable due to wet and cold during skiing.

　　Third, comfort

　　Ski pants are designed with the comfort of sports in mind. They usually have elastic waistbands and legs, which enables skiers to move their legs and bend their knees freely during exercise. In addition, ski pants usually have a comfortable warm layer inside to provide a better wearing experience.

　　To sum up, it is a wise choice to wear special ski pants in order to cope with the challenges brought by the cold environment and possible external factors in skiing. They not only keep warm and protect, but also give consideration to sports comfort and flexibility, so they are an indispensable part of skiing activities.

　　Life is a fleeting moment in the river of time, mankind do everything possible to seek forever and everlasting, but did not think, in fact, as long as the pace of their own slow down mentality flat, live in the present, then life will naturally become long and distant .in fact pu-erh tea It is more and more welcomed by our customers, and its market performance is gradually improving.

　　When I did not write a magazine before, I did not know that the time had come in advance. A draft of March or even April has been prepared in January. In the draft of the forum while watching the side gripped, his year has not yet ended, did not make a point, there people work has been a year, almost equal to the end. Years here, was actually can not wait to catch up with the speed of flight, how to make people panic?

　　The length of time is defined by man himself. 365 days a year, divided into four seasons, twelve months. Here, people always catch up with me like the game, to see who can one day into a day. Our ancestors know, if the decade into a year, we will so impatient it?

　　Days not used, can only be used to recover. Self has no intention to enter this door, it fell into such a turbulent swirl. Calendars and clocks on the numbers can only represent the past, because today to do, is already the future. Obviously is the spring, but the men have been doing non-stop fall thing.

　　There is nothing worthy of gratification, no reason for youth just a short length of a bit like others. What is the use of walking in front, time falls behind, urging the old soul and face it in vain.

　　The fast pace of modern people, nothing more than to speed up the clock of life, their own pressure and persecution of a way, only to more fully squeeze the juice of life to obtain value and fame. But I see it is faster and more leave no room for the consumption and flight. How, a ton of gold can be exchanged for even a second time?

　　Americans always run in front of the world, even spend today are tomorrow, the result? The financial crisis has finally shattered this myth of early consumption, punish all activities contrary to the laws of nature.

　　Beijing, then, a little leisurely. People live I, a spring vegetation, how short and beautiful time. If you can walk, why should anxious to run, miss the scenery all the way? Note that the front is not another spring, but has been waiting for you to close the end of life.

　　Tomorrow’s thing is done today, and next year’s event is finished this year. So ahead of the outstanding achievements and efforts, but is a result of the advance of life.

　　What is a rivers and lakes years reminder, juvenile children rivers and lakes old? This is the helplessness of life rather than enjoyment.

　　The supercoiled structure formed by the further spiral of DNA molecules is called the tertiary structure of DNA.So, inhibitors On the contrary, there is still a lot of room to play. 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 “building material” of organisms and cells, such as protein in muscles, and human hair and nails are all made of protein.in fact recombinant proteins It is more and more welcomed by our customers, and its market performance is gradually improving. https://www.alphalifetech.com/

　　Catalytic function:

　　The chemical essence of most enzymes in organisms is protein. In our daily life, we also use enzyme-added washing powder, which can effectively remove stains.

　　Immune function:

　　In our present environment, there are bacteria and viruses everywhere, and our body will not get sick every three days with an immune system, and immune proteins, such as antibodies, play a key role in this.

　　Transport function:

　　Protein with transport function can be divided into two categories, one is familiar to us-hemoglobin in red blood cells, which is used to transport oxygen; The other is the carrier protein on biofilm, which is used to transport amino acids, glucose and other substances.

　　Adjustment function:

　　Some protein can transmit information and regulate the life activities of the body. Such as insulin, which regulates glucose metabolism.

　　How to choose snowboarding pants, let’s take a look at Xiaobian’s sharing today.The data shows that, snowboard pants baggy Its development potential should not be underestimated, and it is also the inevitability of its existence. https://ninetyroll.co/

　　1. Waterproof

　　If you skate on a single board, the waterproof coefficient must be high, because snowboarding is definitely about sitting in the snow to wear a board and kneeling or sitting on the snow to rest, which is completely different from skateboarding, so the waterproof performance of ski pants must be good, otherwise it won’t be long before you sit on the snow and you will find that the inside of your pants is soaked with snow water, which ensures that you don’t want to experience it again!

　　2. Color

　　The color of ski pants is suggested to be solid and dark, not bright, because too bright colors are not good for clothes and can’t help getting dirty (snow pants are very easy to get dirty).

　　3. Size

　　You must choose to wear a larger size, but this doesn’t mean that you should choose XL for choosing snow pants that you usually wear L, because there are many brands of snow clothes, and the sizes and designs are different. Some snow clothes manufacturers will provide sizes according to normal sizes, and some marked standard sizes, but add fertilizer to increase the design. Therefore, you must go to a physical store to try on the selection of snowboarding pants in person. Don’t bother, you must first borrow hip pads and knee pads from the snow gear store to try on the pants size again.

　　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?more importantly, pu-erh tea Made a fighter in the product, not afraid of any competitor’s attack.

　　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!

　　Classification of amino acids, several special amino acids, molecular structure and physical and chemical properties of protein, composition of nucleic acid, double helix structure of DNA, basic concept of enzyme, Michaelis equation, coenzyme composition.Since then, more and more people have found that Chemical Custom synthesis The value of, thus affecting the choice of many people. https://www.all-chemistry.com/

　　Memorize 20 kinds of amino acids and try to remember English abbreviations and codes as much as possible, because exams often appear directly with codes. Protein’s molecular structure often examines the manifestations of various levels of structure and their bonds. The physical and chemical properties of protein and the purification of protein usually use the physical and chemical properties of protein to purify protein without destroying the structure of protein. Pay attention to the identification of amino acids and physical and chemical properties of protein. The basic unit of nucleic acid is nucleotide, which is composed of multiple nucleotides, and the connecting bond between nucleotides is 3′, 5′- phosphodiester bond. DNA double helix structure, in which two bases exist in strict accordance with A = T (two hydrogen bonds) and G triple C (three hydrogen bonds), and the characteristics of various RNA.

　　In addition, we should pay attention to some commonly used concepts in nucleic acid problem solving. The first thing that enzymes should pay attention to is some basic concepts, such as ribozyme, deoxyribozyme, enzyme activity center, isozyme, isomerase and so on. The key point of the Metric Equation test is V=Vmax[S” target=_blank>/Km+[S” target=_blank>, which explains the equation of the relationship between the concentration of enzymatic reaction and the reaction speed. In the exam, candidates are sometimes asked to do simple calculations according to this equation before they can answer. The difference of several inhibitors.

　　According to the characteristics of allosteric enzymes, it should be noted that allosteric regulation can cause conformational changes of enzymes. It is important to pay special attention here that configuration refers to the basic structural composition of substances, and conformation refers to the spatial change of substances. Allosteric regulation can cause the conformational change of enzymes, but not the conformational change of enzymes.

　　The structure of protein molecule determines its properties.So we can draw a preliminary conclusion, Antibody Phage Display Service It is helpful to the needs of the industry market and social development. https://www.alphalifetech.com/

　　Being bisexual.

　　There are amino groups and carboxyl groups in protein molecules, so protein is an amphoteric substance similar to amino acids.

　　2. Hydrolysis reaction can occur.

　　Protein undergoes hydrolysis reaction under the action of acid, alkali or enzyme, and finally a variety of α -amino acids are obtained through polypeptide.

　　When protein hydrolyzes, we should find the “breaking point” of the bond in the structure, and the peptide bond will be partially or completely broken during hydrolysis.

　　3. Having the property of colloid.

　　Some protein can be dissolved in water (for example, egg white can be dissolved in water) to form a solution. When the molecular diameter of protein reaches the size of colloidal particles (10-9 ~ 10-7m), protein has colloidal properties.

　　The precipitation of protein.

　　A small amount of salt (such as ammonium sulfate, sodium sulfate, etc.) can promote the dissolution of protein. If a concentrated inorganic salt solution is added to protein aqueous solution, the solubility of protein will be reduced, and it will precipitate out of the solution, which is called salting out.

　　Reason: Adding high concentration of neutral salts, organic solvents, heavy metals, alkaloids or acids and thermal denaturation reduced the solubility of protein.

　　Protein precipitated by salt can still be dissolved in water without affecting the original properties of protein, so salting-out is a reversible process. Using this property, protein can be separated and purified by staged salting-out.