January 19, 2022
Protein (蛋白質, cultural language: egg cow) is a macromolecular organic substance that composes the body of an organism in biochemistry. It is also called white matter. Protein The English name protein is derived from the Greek word proteios (important). As can be seen from the Chinese character for protein, dan (蛋) means bird egg, protein is the main component that makes up the white of bird eggs such as eggs. The Chinese word for protein comes from the German word Eiweißstoff (German: Eiweißstoff), which literally means "white matter". Polypeptide is a linkage of numerous amino acids, in which 20 different amino acids are long linked by chemical bonds called peptide bonds. It is only called a protein when various polypeptide chains form a quaternary structure and have unique functions. Although a protein and a polypeptide are technically different molecules, they are sometimes used without distinction in some cases. In general, if the molecular weight is relatively small, it is called a polypeptide, and if the molecular weight is very large, it is called a protein. Proteins play important roles in various forms, such as components in living organisms, catalysis of various chemical reactions in cells (enzymes), and immunity by forming antibodies. The formula is (NH2CHRnCOOH)n. Proteins are digested by the action of a proteolytic enzyme called trypsin. However, soybeans contain a protein called a soytrypsin inhibitor that interferes with the activity of trypsin, so eating raw soybeans is difficult to digest. However, when soybeans are heated, this protein component is denatured and the inhibitory function is lost. In the end, trypsin is activated, making it easier for digestive enzymes to invade. Protein denaturation is caused by physical factors (heating, drying, stirring, pressure, X-rays, ultrasonic waves, vibrations, freezing) or chemical factors (acids, bases) of natural proteins. , urea, organic solvents, heavy metals, surfactants) or the action of enzymes, etc.