Origin of the name protein
The name proteins comes from its properties in living organisms, specifically its egg-white-like nature. Specifically, scientists have observed that there is a class of substances in living organisms that, when heated, solidify like egg whites. Based on this observation, chemists named these substances “proteins”, a word derived from the Greek word “πρωτεινα” (prÅteios) meaning “first”, because proteins are essential for life. The word “protein” was chosen because proteins are indispensable for life's activities. The name “protein” was chosen to emphasize the importance of these biomolecules in maintaining life and performing vital functions. Proteins are involved in structural support, enzymatic reactions, cell signaling, immune responses, transport and many other biological processes. They are made up of amino acids linked together by peptide bonds to form long chains that fold into specific three-dimensional structures to fulfill their functions.
Basic Properties of Proteins
Proteins are the main bearers of life activities, the basic organic matter that constitutes cells and the material basis of life. Without proteins, there is no life. The basic unit of protein is amino acid, which are combined in different proportions to form various proteins, which are constantly metabolized and renewed in the body. Proteins account for 16% to 20% of the body's weight, and for a 60-kilogram adult, his or her body contains about 9.6 to 12 kilograms of proteins.
Chemical Properties of Proteins
Proteins are composed of carbon, hydrogen, oxygen and nitrogen, and may also contain elements such as phosphorus, sulfur, iron, zinc, copper and manganese. Proteins are amphoteric, can undergo hydrolysis reactions, and have colloidal properties when dissolved in water. In high concentrations of neutral salts, organic solvents or acids, proteins are prone to precipitation. In addition, proteins are susceptible to denaturation, which can be caused by physical factors such as heating, pressurization, shock, ultraviolet irradiation, or chemical factors such as strong acids, strong bases and heavy metal ethanol.
Functions of proteins
Proteins are the main components that make up the cell, accounting for about 50% or more of the cell's dry weight. They are not only the material for presenting the genetic information of DNA, but also determine the shape and structure of the cell and carry out the functions of the cell. Proteins are macromolecular compounds, with molecular weights mostly above 10,000, consisting of tens to hundreds of amino acids or more. The order of amino acids in proteins is the basis of their structure, but proteins exist in their unique three-dimensional conformation and perform a variety of complex biological functions.
Conclusion
In summary, proteins are called “proteins” because they exhibit properties in living organisms that are similar to egg whites that solidify when heated. This name reflects the importance of proteins in life activities and their unique chemical properties.
