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.
There are 20 amino acids which make up the proteins, distinguished by the R-group. The simplest of the amino acids, glycine, has just H as an R-group. Amino acids are the structural elements from which proteins are built. When amino acids bond to each other, it is done in the form of an amide, making a connection which is called a peptide linkage. This can be illustrated with the two simplest amino acids, glycine and alanine.