Podcast
Questions and Answers
Which of the following is the first committed step in purine nucleotide biosynthesis?
Which of the following is the first committed step in purine nucleotide biosynthesis?
Which enzyme catalyzes the formation of 5-phosphoribosylamine in purine biosynthesis?
Which enzyme catalyzes the formation of 5-phosphoribosylamine in purine biosynthesis?
Which molecule serves as the precursor for the ribose sugar in purine biosynthesis?
Which molecule serves as the precursor for the ribose sugar in purine biosynthesis?
What is the source of the nitrogen in the formation of 5-phosphoribosylamine?
What is the source of the nitrogen in the formation of 5-phosphoribosylamine?
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Which purine base is formed first during de novo synthesis?
Which purine base is formed first during de novo synthesis?
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What is the function of PRPP in purine biosynthesis?
What is the function of PRPP in purine biosynthesis?
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Which amino acid contributes both nitrogen and carbon atoms to the purine ring?
Which amino acid contributes both nitrogen and carbon atoms to the purine ring?
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The enzyme IMP dehydrogenase is responsible for the conversion of IMP to which compound?
The enzyme IMP dehydrogenase is responsible for the conversion of IMP to which compound?
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GMP is synthesized from which intermediate in the purine biosynthesis pathway?
GMP is synthesized from which intermediate in the purine biosynthesis pathway?
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Which enzyme catalyzes the conversion of adenosine to inosine in purine catabolism?
Which enzyme catalyzes the conversion of adenosine to inosine in purine catabolism?
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What is the final product of purine catabolism in humans?
What is the final product of purine catabolism in humans?
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Xanthine oxidase is involved in the conversion of xanthine to which compound?
Xanthine oxidase is involved in the conversion of xanthine to which compound?
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What is the major clinical condition associated with excess uric acid production?
What is the major clinical condition associated with excess uric acid production?
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The conversion of AMP to IMP during purine degradation is catalyzed by which enzyme?
The conversion of AMP to IMP during purine degradation is catalyzed by which enzyme?
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Which compound is a substrate for the enzyme purine nucleoside phosphorylase?
Which compound is a substrate for the enzyme purine nucleoside phosphorylase?
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Hypoxanthine is converted to xanthine by which enzyme?
Hypoxanthine is converted to xanthine by which enzyme?
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Which of the following is NOT an intermediate in purine catabolism?
Which of the following is NOT an intermediate in purine catabolism?
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Which molecule acts as a feedback inhibitor of PRPP synthetase?
Which molecule acts as a feedback inhibitor of PRPP synthetase?
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What is the salvage pathway for purine nucleotides?
What is the salvage pathway for purine nucleotides?
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A key feature of purine nucleotide synthesis is that it occurs mainly in:
A key feature of purine nucleotide synthesis is that it occurs mainly in:
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The purine ring is assembled on which molecule?
The purine ring is assembled on which molecule?
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Which of the following is true about purine catabolism in humans?
Which of the following is true about purine catabolism in humans?
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Purine nucleotides consist of which nitrogenous bases?
Purine nucleotides consist of which nitrogenous bases?
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What does PRPP stand for in purine metabolism?
What does PRPP stand for in purine metabolism?
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Which amino acid is the primary nitrogen donor in purine biosynthesis?
Which amino acid is the primary nitrogen donor in purine biosynthesis?
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The purine ring structure is built on which sugar molecule?
The purine ring structure is built on which sugar molecule?
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Which of the following is a precursor for both purine and pyrimidine synthesis?
Which of the following is a precursor for both purine and pyrimidine synthesis?
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Which of the following is NOT involved in purine biosynthesis?
Which of the following is NOT involved in purine biosynthesis?
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Which organ in humans is primarily responsible for purine synthesis?
Which organ in humans is primarily responsible for purine synthesis?
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What is the main purpose of the salvage pathway in purine metabolism?
What is the main purpose of the salvage pathway in purine metabolism?
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Study Notes
Purine Anabolism (Synthesis)
- First committed step: Formation of 5-phosphoribosylamine
- Enzyme catalyzing 5-phosphoribosylamin formation: Amidophosphoribosyltransferase
- Precursor for ribose sugar: Ribose-5-phosphate
- Nitrogen source for 5-phosphoribosylamine: Glutamine
- Enzyme converting IMP to AMP: Adenylosuccinate synthetase
- Enzyme converting IMP to GMP: IMP dehydrogenase
Purine Catabolism (Breakdown)
- Final product in humans: Uric acid
- Enzyme converting xanthine to uric acid: Xanthine oxidase
- Enzyme converting AMP to IMP: AMP deaminase
- Enzyme converting adenosine to inosine: Adenosine deaminase
- Intermediate in purine catabolism (besides hyoxanthine, xanthine and uric acid): IMP
- Enzyme that converts Hypoxanthine to Xanthine: Hypoxanthine-guanine phosphoribosyltransferase
Purine Salvage Pathway
- Purpose: Recycling free purine bases into nucleotides
- Role of PRPP: Essential molecule in the salvage pathway
Regulation and Disorders
- Feedback inhibitor of PRPP synthetase: ATP, GMP, IMP
Other Questions
- Purine nucleotide components: Adenine and Guanine
- Primary nitrogen donor in purine biosynthesis: Glutamine
- Primary organ for purine synthesis: Liver
- Major clinical condition associated with excess uric acid production: Gout
- Sugar molecule on which purine ring is built: Ribose
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Description
This quiz focuses on the processes of purine anabolism, catabolism, and the salvage pathway. It covers essential enzymes and intermediates involved in the synthesis and breakdown of purines. Test your understanding of how these biochemical pathways function and their significance in human metabolism.
