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.
Proteins. Proteins are made of C, H, O, N and S. The building units of proteins are amino acids. Each amino acid contains an amino group, a carboxyl group, a central carbon and hydrogen, and an R group. Variation on R group defines different amino acids. There are 20 different amino acids.