Molecule based on a carbon atom bonded to two functional groups: a carboxylic acid group COOH and an amine group NH2 to a hydrogen atom, and a variable lateral part also called radical R, different for each of the 20 amino acids.
There are nine apolar or hydrophobic amino acids and 11 polar or hydrophilic amino acids six of which are not electrically charged and five are electrically charged three of which are basic and two are acidic.
Amino acids constitute the basic unit of a protein. Proteins are constituted by the assembly of amino acids through a peptide bond that links the CO carboxyl group of an amino acid to the NH amine group of the next amino acid. The organization of the different amino acids in the macromolecule is characteristic of each protein and controlled by the genes. Proteins are present in all the tissues of a living organism.
Among the 20 amino acids, eight are considered indispensable for man and are respectively:
six apolar amino acids: valine, leucine, isoleucine, L-methionine, phenylalanine and tryptophan;
one unionized polar amino acid: theronine;
and one ionized amino acid: lysine.
They are indispensable because they cannot be synthesized by the organism and must therefore come from food. Meat is particularly rich in very high-quality proteins, it contains all the indispensable amino acids in variable proportions.
Molecule based on a carbon atom bonded to two functional groups: a carboxylic acid group COOH and an amine group NH2 to a hydrogen atom, and a variable lateral part also called radical R, different for each of the 20 amino acids.
There are nine apolar or hydrophobic amino acids and 11 polar or hydrophilic amino acids six of which are not electrically charged and five are electrically charged three of which are basic and two are acidic.
Amino acids constitute the basic unit of a protein. Proteins are constituted by the assembly of amino acids through a peptide bond that links the CO carboxyl group of an amino acid to the NH amine group of the next amino acid. The organization of the different amino acids in the macromolecule is characteristic of each protein and controlled by the genes. Proteins are present in all the tissues of a living organism.
Among the 20 amino acids, eight are considered indispensable for man and are respectively:
six apolar amino acids: valine, leucine, isoleucine, L-methionine, phenylalanine and tryptophan;
one unionized polar amino acid: theronine;
and one ionized amino acid: lysine.
They are indispensable because they cannot be synthesized by the organism and must therefore come from food. Meat is particularly rich in very high-quality proteins, it contains all the indispensable amino acids in variable proportions.
