Yearly Archives: 2024

　　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.At first, Antibody Phage Display Service It developed out of control and gradually opened up a sky of its own. 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.

　　The reason why people live tired, is not fit the shelf, tear can not open face, untied plot (the reason is very simple)The data shows that, pu-erh tea Its development potential should not be underestimated, and it is also the inevitability of its existence.

　　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).

　　Separation and purification of protein;with small molecules 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. https://www.all-chemistry.com/

　　1. Salting-out and organic solvent precipitation: adding a large amount of neutral salt into protein solution to destroy the colloidal properties of protein and precipitate protein from the solution, which is called salting-out. Commonly used neutral salts are: ammonium sulfate, sodium chloride, sodium sulfate and so on. When salting out, the pH of the solution is the best at the isoelectric point in protein. Any organic solvent that can be mixed with water in any proportion, such as ethanol, methanol and acetone, can cause protein precipitation.

　　2. Electrophoresis: protein molecules have a net negative or positive charge in a solution higher or lower than its pI, so they can move in an electric field. The electrophoretic mobility mainly depends on the amount of charge carried by protein molecules and the molecular size.

　　3. Dialysis: Macromolecules can be separated from micromolecules by the ultrafiltration property of dialysis bag membrane.

　　4. Chromatography: Separation is carried out by using the difference of physical and chemical properties of each component in the mixture and the distribution between the two phases (stationary phase and mobile phase) that are in contact with each other. There are mainly ion exchange chromatography, gel chromatography, adsorption chromatography and affinity chromatography, among which gel chromatography can be used to determine the molecular weight of protein.

　　5. Ultracentrifugation: Using the different densities of substances, after ultracentrifugation, they are distributed in different liquid layers and separated. Ultracentrifugation can also be used to determine the molecular weight of protein, and the molecular weight of protein is directly proportional to its sedimentation coefficient .

　　The structure of protein molecule determines its properties.In addition to domestic, recombinant proteins It has also emerged in the international field and gradually gained the favor of more foreign friends. 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.

　　The first is “poverty”contemporaneity pu-erh tea Our competitors have not made large-scale improvements, so we should get ahead of everyone in the project.

　　Poverty can not wait, because a long time, you will be used to poverty, when not only can not break through the self, or even obliterate their dreams, and mediocre over a lifetime … …

　　The second is “dream”

　　Dreams can not wait, because different stages of life, there will be different experiences and ideas, imagine a problem: If you dream of 20 years old, at the age of 60 was able to achieve, that would be what kind of a situation?

　　For example, your 20-year-old dream is to buy a Ferrari sports car, and then traveled to China’s great rivers and mountains. You have been working hard, finally to 60 years old, and finally to buy a sports car, but to achieve the dream of the young, I am afraid it is beyond the reach of it … …

　　The third is “family”

　　Family can not wait, perhaps we are still young, the future has a lot of time can let us grope, hard, but the family have? They still have time for us to succeed? There is still time for us to make money, so that they have a good life, so that they are proud of us?

　　Trees for static and wind, the child wants to support and pro-not wait. This is a lot of people’s pain, but also a lot of people a lifetime of regret!

　　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.According to related reports, small molecules To a large extent, it leads the changes of market conditions. 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.

　　Protein is a complex organic 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. Amino acids are the basic units of protein, and they are linked into peptide chains through dehydration and condensation. Each polypeptide chain has twenty to hundreds of amino acid residues (-R); Various amino acid residues are arranged in a certain order.with Antibody Phage Display Service 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. https://www.alphalifetech.com/

　　the composition characteristics of protein

　　The amino acid sequence of protein is encoded by the corresponding gene. In addition to the 20 basic amino acids encoded by the genetic code, in protein, some amino acid residues can be modified after translation to change their chemical structure, thus activating or regulating protein. Multiple protein can form a stable protein complex together, often by combining together, and fold or spiral to form a certain spatial structure, thus playing a specific function. The organelles of synthetic peptides are ribosomes on rough endoplasmic reticulum in cytoplasm. The difference of protein lies in the variety, number, arrangement order of amino acids and the spatial structure of peptide chains.

　　Protein is composed of C (carbon), H (hydrogen), O (oxygen) and N (nitrogen), and generally protein may also contain P (phosphorus), S (sulfur), Fe (iron), Zn (zinc), Cu (copper), B (boron), Mn (manganese) and I (iodine).

　　The composition percentage of these elements in protein is about: 50% carbon, 7% hydrogen, 23% oxygen, 16% nitrogen, 0-3% sulfur and other trace amounts.

　　All protein contains N element, and the nitrogen content of various protein is very close, with an average of 16%;

　　Every 1g of N in any biological sample means that there is about 100/16=6.25g protein, and 6.25 is often called protein constant.

　　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 .From the demand side, pu-erh tea More in line with the psychological expectations of consumers, willing to pay for the things they like.

　　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.

　　Enzymes involved in the process of DNA replication, transcription and translation, reverse transcription and reverse transcriptase, the principle of base pairing, the characteristics of genetic code, the interference of protein synthesis, and genes are hot topics in the examination, but the content is scattered.period Chemical Custom synthesis Many adjustments have also been made, and the direction of product research and development has been reversed, in order to better meet the market demand. https://www.all-chemistry.com/

　　In the process of DNA replication, telomere and telomerase are common test sites. Telomerase is an enzyme composed of RNA and protein. The linear DNA end of chromosome can be shortened at the end of replication, but this end shortening can be compensated by template-independent replication of telomere.

　　In the process of telomere synthesis, provided by Chinese medicine, science, website and station, telomerase uses its own RNA as a template to synthesize complementary chains, so telomerase can be regarded as a special reverse transcriptase. Reverse transcription and reverse transcriptase. The similarities and differences between replication and transcription can be seen from the comparison that both DNA replication and RNA transcription follow the principle of base pairing and are in opposite directions. The characteristics of genetic code are the focus of the exam, so everyone should pay attention to memory.

　　Protein is composed of C (carbon), H (hydrogen), O (oxygen) and N (nitrogen). Generally, protein may also contain P (phosphorus), S (sulfur), Fe (iron), Zn (zinc), Cu (copper), B (boron), Mn (manganese) and I (iodine).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 composition percentage of these elements in protein is about: carbon 50%, hydrogen 7%, oxygen 23%, nitrogen 16%, sulfur 0~3% and other trace amounts.

　　(1) All protein contains N element, and the nitrogen content of various protein is very close, with an average of 16%;

　　(2) protein’s coefficient: the existence of every 1g of N in any biological sample means that there is about 100/16=6.25g of protein, and 6.25 is often called protein’s constant.

　　(3) protein is a biopolymer based on amino acids. The sequence of amino acids on protein molecule and the three-dimensional structure formed from it constitute the diversity of protein structure. Protein has primary, secondary, tertiary and quaternary structures, and the structure of protein molecule determines its function.