2. What is purine biosynthesis
• Purines are biologically synthesized as nucleotides and ribosides, i.e. bases
attached to ribose 5-phosphate. Purine metabolism refers to the metabolic
pathways to synthesize and break down purines that are present in many
organisms.
3.
4. Significance of purine synthesis
Purines serve as building blocks of nucleic acids.
ATP plays an important role in energy transformation.
ATP, ADP, and AMP may function as allosteric regulators and participate in regulation of
many metabolic path-ways.
ATP involves in covalent modification of enzymes. ways.
GMP are secondary messengers.
Salvage pathways are used to recover bases and nucleosides that are formed during
degradation of RNA and DNA.
In comparison to de novo pathway, salvage pathway is energy-saving.
In brain and bone marrow tissues salvage pathway is the only pathway of nucleotide
synthesis.
5. What is pyrimidine synthesis
De novo pyrimidine nucleotide biosynthesis which is also referred to as the
orotate pathway is usually defined as the formation of UMP from carbamoyl
phosphate (CP).
6.
7. Significance of pyrimidine synthesis
The action of purine nucleotides on pyrimidine formation is important
because it establishes a balance between the production of both types of
nucleotides, especially for DNA synthesis.
