From the amino acid residues molecules of what are constructed?

Of the amino acid residues, protein molecules have been constructed. Such polymers are high molecular weight natural materials. They contain such chemical elements as carbon, there are hydrogen, oxygen atoms, and nitrogen. Nucleic acids contain phosphorus, and many proteins contain sulfur.

Features of the structure

Since molecules of protein molecules are constructed from amino acid residues, they have a high relative molecular mass. They are called macropolymers. Examples of low molecular weight compounds include alcohols, carboxylic acids, nucleotides, monosaccharides, amino acids.

Macromolecules

It is from the amino acid residues that the protein molecules necessary for the vital functions of living organisms are built. On average, their relative molecular weight is represented in the range of several thousand to one million. In molecules of protein compounds, nucleic acids, polysaccharides, a certain number of repeating units is assumed.

Monomers are simple molecules that are the basis for the formation of a polymer molecule. Which molecules are built of amino acid residues? The answer to this question is familiar to any high school student. Monomer for them are amino acids. For polysaccharides, monosaccharides are needed, and nucleotides are necessary for the construction of nucleic acids.

The importance of biopolymers

So, from the amino acid residues are built protein molecules, which perform several functions at once. It is necessary to note their construction function. It allows to build protein molecules, specific for an individual living organism. In addition, protein molecules are a source of energy, so proteins are included in the daily diet. The cells contain different amounts of organic compounds. For example, for animals, predominance of lipids and proteins is characteristic, and in plants - a sufficient amount of carbohydrates.

Molecules of animal proteins have been constructed from amino acid residues. Such "bricks", which are amphoteric chemical compounds, line up in a protein molecule in a certain sequence. At present, there is information about the existence of two hundred amino acids, but only twenty of them are used to form natural proteins. They are called protein-forming. For example, proteins can be constructed by alternations from alanine, leucine, lysine, aspartic acid, valine, methionine, glutamine, threonine. When asked about the molecules from which amino acids are built, schoolchildren give examples of animal proteins.

Features of chemical structure

In amino acids that are capable of forming macromolecules, the amino group and the carboxyl group are linked to one carbon atom. It is this feature that combines the above-mentioned number. Amino acid residues differ in the composition of the radical. It can be hydrophilic or hydrophobic, polar or non-polar, which gives amino acids specific properties.

Most of the amino acids capable of forming protein molecules have one carboxyl group (it contains hydroxyl and carbonyl) and one amino group, so they are considered neutral molecules.

There are also basic amino acids that have several amino groups, as well as acidic amino acids, which contain several carboxyl groups. For example, sulfur atoms are in the molecule of cysteine.

Synthesis Options

Autotrophic organisms synthesize amino acids from nitrogen-containing inorganic substances, as well as from products of photosynthesis.

Heterotrophic organisms use food as the main source of amino acids. In the human body, some amino acids are synthesized from metabolic products. Such compounds are considered interchangeable. As a source of essential amino acids, unable to synthesize in the human body, a certain food is used. What acids are called irreplaceable for humans? These are lysine, phenylalanine, leucine, valine, isoleucine, tryptophan, methionine. For the child's body there are two more essential amino acids: histidine and arginine.

Since amino acids are amphoteric compounds, they are highly reactive. Between the amino group of one acid and the carboxyl group of the second molecule, a chemical bond is formed called a peptide (amide) bond.

As a result of this chemical reaction, a linear structure of the peptide is formed. One end of the new compound has an amino group, and the second has a free carboxyl group. This structure allows the dipeptide to interact with other amino acid molecules, to form polypeptide compounds.

Conclusion

Peptides are of particular importance for human life. Polypeptides in their structure are toxins, antibiotics, and also part of hormones. Polypeptide chains can contain thousands of amino acid residues in a sequence. If there are only amino acid residues in the protein macromolecules, they are called simple amino acids.

If in the structure of the protein molecule there are not only amino acid components, but also cations of iron, manganese, zinc, sugar, nucleotides, lipids, in this case the molecules are called complex proteins. As common simple proteins, we select fibrin, albumins of blood, enzymes.

Complex proteins are considered to be antibodies (immunoglobulins), enzymes. There are four types of structural organization of protein molecules. The primary structure is a linear sequence of amino acid residues connected by peptide (amide) bonds.

It determines the functions, properties, as well as the shape of the protein. On the basis of the primary structure, other variants of structures are created. Each organism has its own unique primary structure, which creates certain problems for synthesis. For example, problems arise in the selection of pharmaceuticals for specific people.