Nucleic acid

Question 1

What is Nomenclature?

Answer 1

A unit consisting of a base bonded to sugar is refferred to as a nucleoside

A nucleoside joined to one or more phosphate groups in nucleotide

names change based on phosphorylation

Question 2

Explain De novo synthesis

Answer 2

Nucleobase (or nucleoside) is synthesized from simpler starting materials, including amino acids

ATP hydrolysis is required for de novo synthesis

Common pathways with small variations to synthesise different nucleoside phosphates

Question 3

Explain Salvage pathways

Answer 3

Nucleobase is reattached to a ribose, activated in the form of 5-phosphoribosyl-1-pyrophosphate (PRPP).

Question 4

Explain the synthesis of ribonucleotides

Answer 4

DNA requires deoxyribonucleotides

All deoxyribonucleotides are synthesized from the corresponding ribonucleotides

Question 5

Explain Purine Nucleotide Biosynthesis

Answer 5

Three amino acids, formate and CO2 required

N1 Asparatate amino group

C2 and C8 from formate

N3 and N9 from glutamine amide group

C4, C5 and N7 from glycine

C6 from CO2 (as HCO3)