Purines

               Purines are one of the two groups of nitrogen-containing organic molecules: the nitrogenous bases. The molecules of this family are non-polar and planar. Nitrogenous bases are, mostly, involved in the structure of the genetic material in living organisms.

                All purines are considered heterocyclic molecules, which have a double-ring structure that consists of a pyrimidine ring fused to an imidazole ring.  Each purine’s ring has two nitrogen atoms, which are located in the same place in all purines. The other positions within the rings are occupied by carbon atoms.  The purine ring is encircled by hydrogen atoms, which can be replaced by other atoms or groups of atoms, generating other forms of purines.

                This group of nitrogenous bases is very abundant in nature. We can find it in the nucleic acids: adenine (6-amino purine) and guanine (2-amino-6-oxypurine) are two of the five bases of DNA and RNA structure.  Caffeine and theobromine are also purines, present in plants, known because of their stimulant proprieties.

                We don’t find this kind of molecules only in DNA or RNA in our cells. They also have an important role in metabolic processes. Take the example of ATP, adenosine triphosphate, which derives from adenine.  Its ability to store and transfer energy, which also happens with GTP and coenzyme A, allows this molecule to interfere in almost every metabolic processes. 

Curso: Bioquímica 2ºano
UC: Biologia Molecular
Ano letivo: 2013/2014
Grupo de trabalho 5:
Ana Raquel Bertão A67384
Ana Margarida Pacheco A67372
Helena Rodrigues A67383
Renata Oliveira A67356