Science 2025, January

The article discusses in detail the chemical structure of the amino acid cysteine. Several options for writing the structural formula of a substance are presented. Two schemes for the formation of tripeptides with the participation of cysteine are presented. Attention is paid to the thiol group. The synthesis of cysteine from methionine is considered. A table of foods with a high content of the substance is given. The biological role of cysteine is described. Last modified: 2025-01-10 15:01

The characteristic of the nitrite ion is given. The physical and chemical properties of nitrites, including redox ones, are described. Methods for the qualitative detection of nitrite ions and their quantitative determination by photometry with sulfanilic acid are presented. Examples of obtaining nitrites are given. Last modified: 2025-01-10 15:01

Quantitative analysis is a large section of analytical chemistry that allows you to determine the quantitative (molecular or elemental) composition of an object. It is used to determine the composition of ores (to assess the degree of their purification), the composition of soils, plant objects. In ecology, quantitative analysis methods determine the content of toxins in water, air, and soil. In medicine, it is used to detect counterfeit medicines. Last modified: 2025-01-10 15:01

The article gives the formula of isopropanol, describes the physical and chemical properties. The fact of high boiling point and solubility in water is explained by the presence of hydrogen bonds. The main physical characteristics of the substance are given. The reactions of obtaining isopropanol are given, the volumes and enterprises of production in Russia are indicated. The options for using the substance in various areas of the national economy are considered in detail. Briefly describe the harm of the substance. Last modified: 2025-01-10 15:01

Carbohydrates are an extensive group of organic substances that, together with proteins and fats, form the basis of the human and animal body. The totality of all reactions for the breakdown of food carbohydrates to glucose and the synthesis of new molecules from it, as well as other numerous transformations of these substances in the body, is called carbohydrate metabolism in biochemistry. Last modified: 2025-01-10 15:01

Gold. This mysterious and alluring metal has occupied the souls and minds of mankind since ancient times. All known civilizations revered gold, extolling it as something divine. Why is metal so attractive? What caused its boundless popularity?. Last modified: 2025-01-10 15:01

Nothing immerses you in the atmosphere of the Middle Ages like bright panels of coats of arms. Want to know more about them? Then get ready to figure out what heraldry is. Last modified: 2025-01-10 15:01

The name of Ivan Matveyevich Vinogradov is inscribed in golden letters in the history of world mathematics. The scientist made a significant contribution to the analytical theory of numbers and created the method of trigonometric sums. He is the only mathematician in Russia, in whose honor a memorial museum was organized during his lifetime. Last modified: 2025-01-10 15:01

Since the formation of the globe, the base of the surface has been constantly in motion. The earth's crust, when moving, can lead to terrible consequences in the form of such a phenomenon as an earthquake. When one plate crawls onto another, the internal stress of the continental crust accumulates; when passing through a critical point, the accumulated energy is released, causing terrible destruction. Last modified: 2025-01-10 15:01

Strontium (Sr) is a chemical element, an alkaline earth metal of the 2nd group of the periodic table. Used in red signal lights, phosphors and poses a major he alth hazard in radioactive contamination. Last modified: 2025-01-10 15:01

The biography of Democritus is very curious. The summary of his works is no less interesting. If you have not met this thinker yet, we invite you to do so. Democritus is an ancient Greek philosopher whose years of life are from about 460 to 360 BC. e. He is known for being the founder of the atomistic doctrine. According to Democritus, only emptiness and atoms exist in the world. Last modified: 2025-01-10 15:01

Sodium carboxymethylcellulose: description of the chemical compound, empirical and structural formulas. Methods for obtaining a substance. Physicochemical characteristics. Applications, impact on the human and animal body, hazard class. Last modified: 2025-01-10 15:01

The article discusses such a phenomenon as the parade of planets, and its influence on the fate, character and other traits of a person. Last modified: 2025-01-10 15:01

Are there many chemically pure substances in nature? What is sea water, milk, steel wire - individual substances, or do they consist of several components? In our article, we will get acquainted with the properties of solutions - the most common physico-chemical systems that have a variable composition. Last modified: 2025-01-10 15:01

Coal is a fairly complex substance from a chemical point of view. In fact, it does not consist of one substance, but of a whole multitude. But there are several types of coals, so their composition will be very different. This article describes the composition of each type of fossil coal, as well as charcoal and activated carbon. Last modified: 2025-01-10 15:01

The article describes such an organic substance as aniline. Such aspects as obtaining aniline, its physical and chemical properties are disclosed in detail. A little is told about its poisoning effect and help in case of intoxication. Last modified: 2025-01-10 15:01

The article describes such a substance as hydrogen chloride, and its aqueous solution - hydrochloric acid. The chemical and physical properties, methods of obtaining it in industry and laboratory, as well as safety precautions when working with it are analyzed in detail. Last modified: 2025-01-10 15:01

The article describes such a substance as nitrobenzene. Particular attention is paid to its chemical properties. Methods for its production (both in industry and in the laboratory), toxicology, structural formula. Last modified: 2025-01-10 15:01

The chromosome theory of heredity, or Morgan's chromosome theory, as it is also called, has become a key to the development of all modern genetics. Morgan's famous fruit fly experiments elucidated complex phenomena such as linked inheritance and crossing over. Learn more about this theory, its main provisions and features. Last modified: 2025-01-10 15:01

Throughout the long history of science, ideas about heredity and variability have changed. Even in the time of Hippocrates and Aristotle, people tried to conduct breeding, trying to bring out new types of animals, plant varieties. When carrying out such work, a person learned to rely on the biological patterns of inheritance, but only intuitively. Last modified: 2025-01-10 15:01

The word "demography" was formed from the words "demos" and "grapho". Translated from Greek, they mean "people" and "I write" respectively. Last modified: 2025-01-10 15:01

Where was the great mathematician Joseph Louis Lagrange born? How did his acquaintance with science begin, how did his career proceed? Answers to questions - in the article. Last modified: 2025-01-10 15:01

The beautiful and mysterious Moon excited the minds of ancient thinkers long before the advent of modern astronomy. Even then, people began to understand how the influence of the moon on the earth is expressed. So, already in the period of Antiquity, the relationship between the cycle of the night star and the tides was noticed. Today, science knows almost everything about the impact of the moon on our planet. Last modified: 2025-01-10 15:01

There are hysteresis magnetic, ferroelectric, dynamic, elastic. It is also found in biology, soil science, economics. Moreover, the essence of this definition is almost the same. But the article will focus on the magnetic, you will learn more about this phenomenon, what it depends on and when it manifests itself. This phenomenon is studied in universities with a technical focus, it is not included in the school curriculum, so not everyone knows about it. Last modified: 2025-01-10 15:01

The starry sky is mesmerizing. Although today the pleasure of seeing the Milky Way is very difficult - the dustiness of the atmosphere, especially in cities, significantly reduces the ability to see a star in the night sky. That is why a trip to the astronomical observatory becomes a revelation for the layman. And the stars again begin to instill hopes and dreams in a person. There are about 60 observatories in Russia, the most important ones will be discussed in this article. Last modified: 2025-01-10 15:01

Gravity collapse is the last stage of stellar evolution. Its consequence could be the formation of a neutron star or a black hole. Last modified: 2025-01-10 15:01

The average person's knowledge of the cosmos is rather superficial. Usually limited to the Sun, Moon, major planets and stars at night. And, of course, everyone knows that all space objects have an orbit and rotate. They move in a circle, which, however, with surprises. Last modified: 2025-01-10 15:01

Forests are essential in human life. They not only form the parameters of the air environment necessary for life, but also act as a source of a valuable resource - wood. And that's not to mention the role the forest plays in the overall ecosystem. Last modified: 2025-01-10 15:01

Soviet, and then Russian scientist, academician of the Russian Academy of Sciences, Zhukov Vasily Ivanovich in 2006 organized the Social University of Russia and became its first rector. All the activities of this party functionary took place in the field of social sciences and in the field of the Ministry of Education. It was here that Vasily Ivanovich Zhukov became an Honored Scientist of the Russian Federation and received an award from the Government of the Russian Federation. Last modified: 2025-01-10 15:01

The phenomenon of friction in human life plays both a positive and a negative role. On the one hand, without its presence, movement would be impossible, on the other hand, due to friction, huge losses of energy and working materials occur. In the article, we will consider from the point of view of physics what friction is, as well as how to find the coefficient of friction. Last modified: 2025-01-10 15:01

What is the effect of electromagnetic fields on the human body, and why is the invisible force manifested so strongly in the form of ailments and poor he alth? How is our biofield protected from magnetic waves? Will the "shell" of a person be destroyed if it is experimentally acted upon with special force?. Last modified: 2025-01-10 15:01

Bromothymol blue refers to laboratory chemicals. It is mainly used for titration of weak acids and alkalis. The color of the solution changes from yellow to intense blue. There are other areas of application. Last modified: 2025-01-10 15:01

The transformer is a versatile piece of equipment needed in power plants, businesses and even homes. Almost every electrical device provides for the presence of this device to lower the voltage coming from the outlet. Last modified: 2025-01-10 15:01

Outstanding biologist Alexei Yablokov was a man-epoch. He is known as an active world-famous environmentalist, political and public figure, professor and doctor of science. In 2005, the scientist created the Green Russia faction as part of the Yabloko party and led it until the last days of his life. Last modified: 2025-01-10 15:01

A quick glance at the state of science about the study of the mysteries of the human brain, you understand that technology is not yet fully able to dissolve the myths of a sophisticated reader. The size of the studies does not reflect the probability of the truth about our body, which can not be said about the psyche.. Last modified: 2025-01-10 15:01

What is the combustion temperature of diesel fuel. Consider the most established combustion model for a conventional diesel engine. This process is primarily controlled by mixing, which can occur due to the diffusion of fuel and air before ignition. Last modified: 2025-01-10 15:01

Metrology is the science of measurement. It establishes a common understanding of the units that are critical to the measurement of any human activity. Modern metrology dates back to the period of the French Revolution, when it was necessary to standardize units in France. Then a single length standard was proposed, taken from scientific sources. Last modified: 2025-01-10 15:01

A dog with two heads is an experiment of the 20th century that was left without much attention in the USSR, but caused a stir abroad. The procedure looks intimidating, but the results that Demikhov received stun every person. Last modified: 2025-01-10 15:01

Rose is one of the most popular flowers in the world. Many love it for its exceptional aroma and sophisticated beauty. When compiling a scientific description of this plant, usually, in addition to the appearance, they talk about growing conditions, a wide variety of rose varieties, their beneficial properties and breeding history. Last modified: 2025-01-10 15:01

No matter where you live in Russia, in any case, you can, raising your eyes to the sky, see the constellation called Crater (lat.), or Chalice. Astronomy lovers who often explore the celestial sphere know that the best time to study this constellation is March. If you are watching the Chalice from the Southern Hemisphere, you will be able to make sure that with the onset of April this constellation occupies the highest position above the horizon. It also has a mythical story about Apollo. Last modified: 2025-01-10 15:01