77 



AMINO ACID 



CH 3 CH COOH 



NH 



NUCLEOTIDE 



NH- 



N 



O 

 = P 



o 



H 



O 



CH- 



/ 

 \ 



C 



^ 



N 

 C. 



N 



N^ 



C C H 



\ ,» « / 



OH OH 



Figure V-l.— Shown are representative examples of an amino acid, a nucleotide. 

 Amino acids are the building blocks of the proteins, while the nucleotides are 

 the building blocks of the nucleic acids. A complete set of these molecules used 

 in biology can be found in the appendix. 



related to the 20 amino acids. For example, the triplet GGG stands 

 for the amino acid glycine. In summary, the "central dogma," which 

 can be stated DNA -+ RNA -> Protein, dictates that the synthesis of 

 proteins is controlled by the nucleic acid and that the genetic code 

 describes the relationship of the simple molecules that make up the 

 strand of nucleic acids and proteins to each other. But where did 

 these simple molecules come from and how were they organized? 



