So, now we've made mRNA in the nucleus. As you recall from the Central Dogma of Molecular Genetics , the next step after transcription is translation , the process of making proteins. Now let's review what amino acids are.
Amino acids are the building blocks of proteins.
Everything your DNA codes for is protein, so your DNA codes for amino acids. There are only 20 amino acids total, but each one has a generalized structure. Each of the 20 different amino acids shares the amino group, the carboxyl group, the Hydrogen atom, and the central Carbon atom. R is simply a symbol for the side group. There is the specialized apparatus for making proteins called the ribosome .