Molecules composed of amino acids that determine the structure and function of every living cell
Proteins are the "raw material of life". They are responsible for the shape and structure of cells and for all metabolic processes. Their tasks are manifold: There are structural proteins (e.g. collagen), enzyme proteins, transport proteins (e.g. haemoglobin), immune proteins, and hormone proteins.
Every human has tens of thousands of different proteins composed of chains of only twenty different amino acids. The amino acids are linked together in long chains folded into characteristic three-dimensional structures. Many proteins are made of more than one amino acid chain.
The properties of an organism essentially depend on the kind, composition, and structure of its proteins. The makeup of proteins is defined in the genetic code (DNA). Simplified: Each gene contains the "construction plan" for one protein. Genetic information is read and transmitted to the cell's protein factories (ribosomes). There, genetic information is translated into a protein product.