I’m inspired by the intricacy of our cells. Inside each cell are tiny molecules which are digesting, healing, sensing, supporting and moving us. Most of this is done by protein molecules – there are 60,000 different proteins in the body, such as enzymes (to carry out reactions) and hormones (send messages). We make proteins when we need them (eg. we build antibodies when we’re attacked by bacteria). In his wonderful book, Our Molecular Nature, David Goodsell writes:
We must be able to build each one exactly when and where it is needed, using only the materials available in the diet.
Why is this building process so accurate? Because each and every cell has a ‘library’ inside it called DNA which contains the precise instructions to build molecules. This ingenious library is used every second of your life. DNA has 6 billion bits of information; the equivalent number of books in a library.
Ultimately, a single cell, when paired with an appropriate mate, can build an entirely new human being, molecule by molecule. -David Goodsell
Using this blueprint, proteins are constructed in chains from smaller molecules called amino acids. Like letters of the alphabet, there are only 20 amino acids arranged to create thousands of novel proteins. Some proteins last a long time, others are disassembled after a few minutes. This allows the body to respond rapidly to any needs. The illustration (right) shows ubiquitin, a protein found throughout your body. Ubiquitin’s job is to attach to discarded proteins, tagging them for destruction.
Illustration of Ubiquitin © David S. Goodsell, the Scripps Research Institute.