Every living organism can be seen as protein structures filled with water and sometimes bones.
It is estimated that the human body may contain more than two million proteins, encoded by just 20,000 to 25,000 genes. The total number found in Terran biological organisms must exceed ten million, but no one knows for sure. Data is available on just over a million of them, drawn primarily from information found in more than 100 genomes that have been fully sequenced.
Useful genetic information found in DNA codes for a corresponding protein.
The field that analyzes proteins in general and aims to comprehensively characterize all those in the human body is called proteomics. Many see the next logical step after the completion of the Human Genome Project to be the start of a Human Proteome Project. The Human Proteome Organization was founded to pursue this goal.
Proteins are long molecular chains made of the 20 basic building blocks of life, amino acids. The oldest known, titin, also known as connectin, contains 26,926 amino acids. Titin is found in muscles and contributes to their passive stiffness. Since the 20 amino acids can be connected in arbitrary sequences, the total space of possible proteins is exponential, with a value of approximately 20 50,000 – a tremendous number. In that space, there may be cures for every disease or ailment, but locating them in such vast numbers is a profound computational and theoretical challenge.
Scientists have discovered that there are 20,000-25,000 protein-coding genes in the human genome.
The word protein comes from the Greek prota, which means “of primary importance”. This is a fitting name, as its central importance in the human body cannot be overestimated. All biological organisms can be seen fundamentally as water-filled protein structures and sometimes supported by mineralized tissues called bones. For almost everyone, there is another one that can break it down. Sometimes they coalesce into mutually cooperative units called complexes, which perform useful biological functions. Each section of useful genetic information, found in DNA and some RNA, encodes a corresponding protein that fulfills a useful biological role.