Nucleic Acids Metabolism

A collection of flashcards summarizing key concepts about nucleic acids and their metabolism.

What are nucleic acids primarily made of?

Nucleotides.

What are the two main processes of nucleic acid metabolism?

Biosynthesis (anabolism) and degradation (catabolism).

What is a significant focus within nucleic acid metabolism?

Purine metabolism and regulation.

What essential cellular functions depend on nucleic acid metabolism?

Replication, transcription, and translation.

How does nucleic acid metabolism relate to cancer therapy?

Targeting nucleic acid metabolism pathways has led to chemotherapeutic agents that inhibit DNA synthesis or repair.

What role does nucleic acid metabolism play in genetic disorders?

It aids in the diagnosis and treatment of genetic diseases and enables gene therapy approaches.

What type of treatments utilize nucleoside analogs?

Antiviral treatments for viral infections.

What is personalized medicine in relation to nucleic acids?

It tailors treatments based on individual genetic profiles, influenced by advances in genomics and RNA sequencing.

What do nucleic acids dictate in proteins?

Amino acid sequence.

From where do nucleic acids provide information?

Chromosomes, passed from parent to offspring.

What is the central dogma of molecular biology?

Replication, transcription, translation.

What is the purpose of reverse transcription in the context of HIV?

It converts viral RNA into DNA.

What do fusion inhibitors like Enfuvirtide target?

The CD4 receptor in HIV treatment.

What is the function of nucleotides?

They provide the building blocks for nucleic acids.

What structure do nucleotides form when linked?

Nucleic acids.

How is the primary structure of nucleic acids determined?

By the nucleotide sequence.

What linkage connects nucleotides in nucleic acids?

3’-5’ phosphodiester linkage.

What is ribose in the context of nucleic acids?

A sugar component of nucleotides.

What is a key regulatory step in purine biosynthesis?

Conversion of PRPP to 5-Phosphoribosyl-1-amine.

What inhibits Amidophosphoribosyl transferase?

The end products IMP, AMP, and GMP.

What are the major regulatory enzymes in purine nucleotide biosynthesis?

PRPP synthetase, Glutamine phosphoribosyl amidotransferase, adenylosuccinate synthetase, IMP dehydrogenase.

What is the significance of IMP in purine metabolism?

It is the precursor for AMP and GMP.

Which drug is a competitive inhibitor of dihydrofolate reductase?

Methotrexate.

What contributes to purine nucleotide synthesis regulation?

Feedback inhibition and feedforward activation.

What are salvage pathways?

Reutilization of bases from dietary or catabolic sources.

What is the end product of purine metabolism in humans?

Uric acid.

What is Orotic aciduria?

An inherited disorder caused by a deficiency of orotate-phosphoribosyltransferase.

How does LLVM inhibitors impact purine synthesis?

By inhibiting enzymes in nucleotide synthesis pathways.

What common condition is associated with high uric acid levels?

Gout.

What is Lesch-Nyhan syndrome?

A genetic disorder due to deficiency of HGPRT, leading to cognitive deficits and hyperuricemia.

What role do enzymes play in nucleic acid metabolism?

They catalyze the reactions necessary for nucleic acid synthesis and degradation.

What is the role of PRPP in nucleotide synthesis?

It acts as a ribose-5-phosphate donor.

What does the drug allopurinol inhibit?

Xanthine oxidase.

What is a potential outcome of poor purine metabolism?

The development of kidney stones.

What is the regulatory control mechanism in pyrimidine biosynthesis?

Feedback inhibition by CTP and activation by ATP.

How are nucleosides formed from nucleotides?

By dephosphorylation through nucleotidase.

What is a common characteristic of purine and pyrimidine catabolism?

Degradation leads to nitrogenous waste products like uric acid.

How is uric acid metabolized in primates?

It is excreted as the end product of purine metabolism.

What happens in pyrimidine metabolism in the context of nucleotide salvage?

Recycling of free pyrimidine bases back into nucleotides.

What is the action of nucleoside phosphorylase?

It converts nucleosides into bases and ribose-1-phosphate.

What is the impact of de novo and salvage pathways on nucleotide metabolism?

De novo pathways create nucleotides from scratch, while salvage pathways recycle existing bases.

Which enzyme is targeted in methotrexate therapy?

Dihydrofolate reductase.

What do ribonucleoside diphosphates differentiate from deoxyribonucleotides?

They contain a hydroxyl group at the 2' position of the sugar.

What are feedback inhibitors in purine synthesis?

AMP, GMP, and IMP that regulate various enzymes in the pathway.

How does acyclovir function as an antiviral drug?

It inhibits viral DNA polymerase by being converted to its triphosphate form.

What disease is associated with HGPRT deficiency?

Lesch-Nyhan syndrome.

What enzyme catalyzes the conversion of IMP to AMP?

Adenylosuccinate synthetase.

Which molecules are the primary substrates in pyrimidine de novo synthesis?

Carbamoyl phosphate and aspartate.

How are urates managed in humans with high levels?

They can form urate crystals and may be treated with allopurinol.

What factors regulate the activity of purine biosynthesis enzymes?

Nucleotide concentrations and metabolic feedback.

What are protease inhibitors used for in viral treatments?

To prevent the maturation of viral proteins.

What are the consequences of disrupted purine metabolism?

Gout, kidney stones, and associated pain.

What is the importance of FAD in xanthine oxidase activity?

It acts as a cofactor required for the enzyme's function.

What role do methotrexate and sulfonamides play in cancer treatment?

They inhibit nucleotide synthesis critical for rapidly dividing cells.

What is the function of dihydropteroate synthase?

It catalyzes the formation of dihydropteroic acid in folate metabolism.

What is the relevance of FLUOROURACIL in cancer therapy?

It inhibits thymidylate synthase, affecting DNA synthesis.

How are uric acid levels managed when treating cancer patients?

By using allopurinol to prevent high uric acid due to cell lysis.

What metabolic pathway is disrupted in Von Gierke's disease?

Glycogen metabolism and glucose production.

What characterizes pyrimidine catabolism?

Dephosphorylation of nucleotides and degradation to bases.

How is uridine utilized therapeutically?

To bypass deficiencies in pyrimidine metabolism.

What vital function do purines and pyrimidines serve?

They are fundamental components of DNA and RNA.

What is the primary product of adenine degradation?

Uric acid.

Which enzyme is essential in the salvage pathway of pyrimidines?

Pyrimidine phosphoribosyl transferase.

What is the clinical application of mycophenolic acid?

An immunosuppressant to prevent organ rejection.

How does glucokinase differ in its function compared to other kinases?

It is specific for glucose and plays a role in metabolic regulation.

What type of regulatory control is seen in both purine and pyrimidine biosynthesis?

Feedback inhibition based on product accumulation.

What is the significance of ribose-5-phosphate in nucleotide synthesis?

It is a precursor for the formation of nucleotides through PRPP.

What does adenosine deaminase catalyze in the degradation pathway?

The conversion of adenosine to inosine.