Protein

PROTEIN Proteins are polymers composed of amino acids. Proteins are important components or main components of animal and human cells. Because cells are the building blocks of our body, the protein contained in food functions as the main substance in the formation and growth of the body. Protein is part of all living cells and is the largest part of the body after water. All enzymes, various hormones, transporters of nutrients and blood, intra-cellular matrices and so on are proteins. Proteins has a unique function that cannot be replaced by other nutrients, namely building and maintaining cells and body tissues. One polypeptide called monomeric proteins formed protein and those that are formed from several polypeptides, for example hemoglobin, are also known as multimeric proteins. Proteins are involved in the immune system as antibodies, control systems in the form of hormones, as storage components (in seeds) and also in nutrient transport. As a source of nutrition, protein acts as a source of amino acids for organisms that are unable to form these amino acids (heterotrophs). Protein was discovered by Jons Jakob Berzelius in 1838. Natural protein biosynthesis is the same as genetic expression. The genetic code carried by DNA is transcribed into RNA, which acts as a template for translation carried out by ribosomes. Until this stage, protein is still "raw", only composed of proteinogenic amino acids. Through posttranslational mechanisms, proteins are formed that have full biological functions. Presence of enzymes as one of protein types play an important role which is chemical processes in the body can take place well because of the presence of enzymes that function as biocatalysts. One of protein types is hemoglobin in red blood cells or erythrocytes which functions as a transporter of oxygen from the lungs to all parts of the body is a type of protein.  Protein Macromolecules Protein as one of biomolecules namely the basic material or macromolecules that make up cells or living organisms. Apart from that, protein biomolecules are the most abundant chemical components in living organisms, this is related to the biological function of proteins which have multiple structural functions in cells, tissues and organs, as enzymes, biocatalysts, and as regulatory substances . Proteins are said to be macromolecules because proteins have the following characteristics : 1. Proteins have a molecular weight ranging from 5,000 – more than 1 million, which is why proteins are classified as macromolecules. 2. The chemical compounds of protein compound components consisting of peptides as submacromolecules, amino acids as molecular units and as components of protein chemical elements consisting of several elements. 3. There are 100.0000 types of protein in human body with its own physiological function. 4. Proteins have a high molar mass 5. Protein is composed of 20 Amino Acids The table below shows the molecular weight and number of protein chains that make up a cell or living organism.  Protein uniqueness Proteins stated to be unique due to several factors, including: 1. Protein can be analogous to a sentence, and amino acids are the alphabet that makes up the sentence. Look at the following 2 sentence examples: a. Rangga likes eating outside the house b. Rangga likes to play outside the house. Number and alphabetical order of the two sentences different so they have different meanings. 2. Protein accompanied by a unique number and sequence of amino acids. 3. Protein acts as an enzyme. 4. Composed of 20 types of amino acids.  Typical protein reactions Millon reaction Millon's reagent is a solution of mercury and mercury nitrate in nitric acid. When this reagent is added to a protein solution it will produce a white precipitate which can turn red by heating. Basically this reaction is positive for enol-phenol because the formation of mercury compounds with colored hydroxyphenyl groups. Proteins containing tyrosine will give positive results. Xanthoprotein reactions The concentrated nitric acid solution was carefully added to the protein solution. After mixing, a white precipitate occurs which can turn yellow when heated. The reaction that occurs is nitration of the benzene nucleus contained in the protein molecule. So this reaction is positive for proteins containing tyrosine, phenylalanine, and tryptophan. Sakaguchi's reaction The reactants used are naphthol and sodium hypobromite. So arginine or proteins containing arginine can produce a red color. This reaction gives positive results if there is a guanidine group.