De novo synthesis - Wikipedia De novo synthesis This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( December 2009 ) De novo synthesis refers to the synthesis of complex molecules from simple molecules such as sugars or amino acids, as opposed to recycling after partial degradation. For example, nucleotides are not needed in the diet as they can be constructed from small precursor molecules such as formate and aspartate. Methionine, on the other hand, is needed in the diet because while it can be degraded to and then regenerated from homocysteine, it can not be synthesized de novo. De novo is a Latin phrase, literally translating to `` from the new, '' but implying `` anew, '' `` from scratch, '' or `` from the beginning. '' Contents 1 De novo DNA synthesis 2 De novo pathways 3 External links 4 References De novo DNA synthesis De novo DNA synthesis is DNA replication without the need for precursor template DNA. It 's also referred to as artificial gene synthesis. Primase is an RNA polymerase, and it can add a primer to an existing strand awaiting replication. DNA polymerase can not add primers, and therefore, needs primase to add the primer de novo. De novo pathways De novo pathways do not use free bases : adenine ( abbreviated as A ), guanine ( G ), cytosine ( C ), thymine ( T ), or uracil ( U ). The purine ring is built up one atom or a few atoms at a time and attached to ribose throughout the process. Pyrimidine ring is synthesized as orotate and attached to ribose phosphate and later converted to common pyrimidine nucleotides. De novo synthesis enzymes are predicted to be present as large multienzyme complexes, although this hypothesis has yet to be thoroughly proven. External links Purine and pyrimidine Metabolism De novo synthesis of purine nucleotides References This cell biology article is a stub. You can help Wikipedia by expanding it. This article related to Latin words and phrases is a stub. You can help Wikipedia by expanding it. Retrieved from `` https://en.wikipedia.org/w/index.php?title=De_novo_synthesis&oldid=791949696 '' Categories : Cell biology Latin biological phrases Cell biology stubs Latin words and phrases stubs Hidden categories : Articles needing additional references from December 2009 All articles needing additional references All stub articles Talk Contents About Wikipedia Deutsch Hrvatski Nederlands Српски / srpski Srpskohrvatski / српскохрватски 中文 Edit links This page was last edited on 23 July 2017, at 13 : 49. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: where does de novo synthesis of purine occur
Answer: attached to ribose