Proteins play an important role in the functioning of the human body. What they consist of, what are their structure and properties, read the article.
General information about proteins and their classification
The value of proteins was determined in the nineteenth century. Scientists have given the name these substances "proteins", which means "first, main." Chemical reactions occurring in a protein have an important feature. They form the basis for the creation of new cells.
Due to the complex structure of protein molecules and the large number of functions performed, it is very difficult for scientists to create a single classification. Therefore, knowledge of proteins was classified according to several criteria:
- According to the composition of chemicals, proteins are simple and complex. What are simple and complex proteins made of? The first includes only amino acids. In complex proteins , non-protein compounds are added to them.
- According to the functional purpose, proteins, organic compounds, differ in several classes:
- Catalytic proteins are enzymes that perform the function of accelerating chemical reactions. Without their participation, processes that are called synthesis and decay are impossible.
- Transport proteins bind hormones, fatty acids and many other compounds of organic and inorganic origin. Then they enter the bloodstream and are transferred to the area of the body where they are needed. These proteins actively transport substances using biological membranes of sugars, lipids, ions and amino acids.
- Proteins that perform a supporting function. With their participation, the cell skeleton is formed. The most common are: collagen, which performs the connective function of tissues, keratin of nails and hair, vascular cell elastin and others. In combination with lipids, they represent the structural basis of membranes.
- Protective function of proteins. Antibodies (immunoglobulins) bind pathogens that enter the body and then neutralize their effect on the human body. Without the participation of thrombin and fibrinogen, blood coagulation is impossible.
- Regulatory function - the protein maintains in a normal state the activity of the body, organs, cells and all processes occurring in the body.
- Proteins give muscle cells the ability to contract, due to which movement is carried out. Using protein receptors, cells in the body perceive information from the external environment, transmit nervous excitement.
What are proteins?
These are high molecular weight compounds of organic composition. What are proteins made of? Twenty types of amino acid residues are involved in their construction, which are connected in series, forming long chains. Prior to scientific research, protein was called the substance of bird eggs, which, when heated, coagulates, and an insoluble mass of white color is formed.
Later, this name was given to many substances of plant and animal origin that have similar properties. The amount of protein in all living organisms prevails over other compounds. Their dry weight is more than half of the total protein mass.
Presumably, in nature there are up to tens of billions of these compounds for individual use. For example: the bacterium of E. coli contains three thousand proteins of various kinds. Proteins include enzymes that are involved in chemical transformations that occur in cells.
Protein composition
Proteins are non-periodic polymers. What simple organic compounds make proteins? Their monomers are twenty types of amino acids. Amino acids are interchangeable and indispensable, depending on the ability to be synthesized in the body. The former have the ability to be synthesized, while the latter do not; moreover, their presence in the body is associated with food intake.
What simple organic compounds make proteins? The composition of amino acids distinguish between full and inferior proteins. The first group is characterized by the content of all amino acids, and the second is distinguished by the absence of any of them.
Proteins containing only amino acids are called simple. If, in addition to amino acids, other components are present - complex. They can be metals, carbohydrates, lipids, nucleic acid.
Simple squirrels
What simple organic compounds make proteins? Read about their composition below. Proteins are called proteins. According to their characteristic properties, they are divided into the following groups:
- Albumin - have the property of dissolving in water, coagulating when heated, not precipitating with solutions of various salts.
- Globulins - do not dissolve in water, but only in solutions of salts of low concentration.
- Histones - are the main nature of the protein in the form of nucleoproteins. The location is white blood cells and blood balls.
- Protamines - they do not contain sulfur. The basic properties are manifested to a great extent. The protein contains nucleoproteins. They are rich in sperm fish.
- Prolamins - well soluble in alcohol. They contain cereal grains. The representative of prolamins is gliadin - the main component of gluten.
- Scleroproteins have the property of not dissolving. Contained in the outer cover of animal bodies, the skeleton and connective tissues. Represented by collagen, keratin, fibroin, elastin.
What simple organic compounds make proteins? They consist of different types of amino acids; there are twenty of them in the protein.
What are the functions of proteins?
Organic compounds (proteins) perform a number of functions:
- Provide metabolic and regulatory processes.
- Perform the delivery of protein to the blood, which provides the necessary substances to all organs.
- Muscle fibers are formed.
- They are the basis of bone and connective tissue.
- Regulate the process of digestion, energy exchange.
- Control the actions of genes.
- Protect the body, strengthening immunity.
Carbohydrates
These are organic compounds of natural origin that charge the body with energy. They are widespread in nature. Their share in plants is seventy to eighty percent of the total mass of all dry substances, in animals - only two. The composition of carbohydrates includes a carbonyl group and a small part of hydroxyl. These compounds are an integral part of tissues and cells in the body. What chemicals are called carbohydrates? The composition of carbohydrates includes oxygen, hydrogen, carbon. Although derivatives of the latter substance differ in their content of other elements, nitrogen, for example.
Carbohydrates are a product of photosynthesis. Without them, biosynthesis in plants is impossible, since they are the starting material for this process. Carbohydrates, being a class of organic compounds, are very diverse. Their role has multifaceted aspects.
Carbohydrate functions
Organic compounds have the following functions:
- Energy - products of the oxidation of compounds (glucose, glycogen, starch) enter the cells, charging them with energy. About sixty percent of the energy expended is compensated by carbohydrates, which supply it to the blood cells. Energy enters the brain, improving its activity.
- Plastic function - compounds are an integral part of many structures at the cellular level; all cells of the body contain them: biological membranes, organelles of cells. With their help, enzymes, nucleoproteins and others are formed.
- Protective function - mucus secreted by the glands protects the internal walls of many organs from various undesirable effects: mechanical, chemical, bacterial. This is achieved due to the high content of carbohydrates in viscous secrets.
- Regulatory function - carbohydrates regulate peristalsis, since the use of fiber with its rough structure irritates the mucous membrane of the digestive tract.
- A specific function - carbohydrates are different. With the help of some of them antibodies are formed, the specificity of blood groups is ensured, and nerve impulses are carried out.