From genes to proteins

Proteins - not genes - are the building blocks of life. They make up muscle fibre, nerve cells or hormones, for example, and also regulate metabolic processes in the form of enzymes or are used as structural proteins in animal or plant cells.

In the cell, proteins are synthesized in the cytoplasm, not in the cell nucleus. The ribosomes or protein factories of the cell are located here. To do their job, the ribosomes need a "production order" from the cell nucleus: this is done by transcribing the genetic code of a gene on the DNA into a chemically closely related molecule.

The transcript acts as messenger RNA. When the gene has been read in the cell nucleus, the messenger RNA travels to the ribosomes, where the genetic code is read out by linking one amino acid to another in accordance with the sequence of bases until a complete three-dimensional protein chain unfolds. The language of the bases is translated into the language of the protein building blocks in this step. It is consequently known as translation.

The triplet code is read from the inside outwards, with each triplet coding for one of 20 amino acids.