Acer executives promote the company's new BYOC strategy. Acer CEO Jason Chen is on far left. Acer Chairman Stan Shih is second to the left. Although the new cloud apps are free, the company wants to include extra features users can choose to pay for.
All proteins are made up of combinations of 20 different amino acids. The RNA code (like DNA) is written in just four different chemical 'letters' - bases. How can a code with four letters identify 20 different amino acids? By reading it three letters at a time - CAU, CAG, GGA, etc.
Protein molecules are often very large and are made up of hundreds to thousands of amino acid units. The 20 amino acids are combined in different ways to make up the 100,000 or so different proteins in the human body. Some of these proteins are in solution in the blood and other fluids of the body, and some are in solid form as the framework of tissue, bone and hair. Shipman, et al. suggests that they make up about 75% of the dry weight of our bodies. Proteins can be characterized as extremely long-chain polyamides.