Test
Purines and Pyrimidines
Preguntas del test (19)
1A rapidly dividing cell will have a greater abundance of which nucleotide?
- AGuanine and Adenine because purine synthesis is more important for a developing cell
- BCytosine and Thiamine because pyrimidine synthesis is less taxing and therefore proceed more quickly
- CThe concentration of pyrimidines and purines will be equal regardless of the conditions
- DPurines are critical for DNA replication, so purine concentration will be higher
2Which of the following is a nucleotide?
- A
- B
- C
- D
- A
3For the previous question why was the correct answer the only nucleotide?
- AIt was the only answer that consisted of a nucleoside bound to a phosphate group
- BAll of the other answers were sugars
- CAll of the other answers were bases
- DNone of the other answers were biologically important molecules
4Which of the following is not a biological function of Nucleotides?
- AThey are precursors to glycogen and other phosphoglycerides
- BNucleotides exclusively compromise the universal energy currency
- CThey serve as metabolic regulators and mediate the action of many hormones
- DNucleotides entirely make up three major co-enzymes: NADH, FAD, and CoA
5cAMP is a nucleotide that mediates hormones
- AVerdadero
- BFalso
6Purine biosynthesis involves which of the following precursors?
- AGlycine
- BGlutamine
- CAspartate
- Dcarbon dioxide
- EFormyltetrahydrofolate
- FAll of the above are required atom contributors
7PRPP (Phosphoribosylpyrophosphate) is the source of the ribose sugar in...
- Apurine de novo synthesis and purine salvage pathways
- Bpurine de novo synthesis
- Cpurine salvage
- Dpurine and pyrimidine de novo synthesis
8Which describes the committed step for purine de novo synthesis?
- AGlutamine-PRPP amido-transferase is the active enzyme
- BPRPP feeds into the committed step
- CGlutamine feeds into the step and becomes glutamate
- DAll of the above
9THF is an enzyme that performs which of the following actions?
- AEliminates an amide group
- BTransfers one carbon from N10-Formyl THF to the growing purine precursor
- CAllosterically activates HGRPT
- DFacilitates a Glutamine dependent nitrogen tranfer
- EFacilitates ring closure of the growing purine
10The base hypoxanthine is described by which of the following statements?
- AInosinic Acid (IMP) is the nucleoside form of hypoxanthine
- BHypoxanthine is critical only to the conversion of IMP to GMP not IMP to AMP
- CHypoxanthine is reduced to xanthine during the purine synthesis pathway
- DThe oxidation of hypoxanthine to xanthine is blocked by allpurinol
11PRPP impacts which of the following?
- ADe novo synthesis of purines
- BDirect production of IMP through PRPP's reaction with Hypoxanthine
- CDirect production of GMP through PRPP's reaction with Guanine
- DAll of the above are catalyzed by HGPRT and all are true in healthy cells
12Which of the following is deficient in Gout?
- AHGPRT
- BADA (adenosine deaminase)
- CPNP (purine nucleoside phosphorylase)
- DYou have to be more specific, gout could be the result of numerous enzyme deficiencies
- EXO (xanthine oxidase)
13Lesch Nyhan Syndrome is caused by a deficiency in which of the following?
- APRPP
- BXO (xanthine oxidase)
- CADA (adenosine deaminase)
- DHGPRT
- EYou have to provide more information, Lesch Nyhan Syndrome could be caused by the deficiency of a number of different enzymes
14Which is the committed step of Pyrimidine synthesis?
- AAspartate Transcarbamoylase ATCase
- BDihydroorotase
- COPRT
- DCTP synthetase
15Familial Orotic Aciduria can be treated using which of the following methods?
- AThere is no curative treatment, simply a management of symptoms
- BDelivery of large doses of orally administered uridine to simply bypass the early steps of pyrimidine synthesis
- CDelivery of large doses of the missing/deficient orotate phosphoribosyltransferase (OPRT)
- DDelivery of fully synthesized pyrimidines for uptake into the cell
16Which of the following are made by a two enzyme complex (Thymidylate Synthetase and Dihydrofolate reductase) after ribonucleotide reductase acts on freshly minted purines and pyrimidines?
- AdADP
- BdGDP
- CdCDP
- DdUDP
- EdTTP
17dATP is the master negative regulator of Ribonucleotide Reductase.
- AVerdadero
- BFalso
18Which of the following enzymes should I know really well?
- ARibosomyl Reductase
- BPRPP Synthetase
- CXanthine Oxidase
- DDihydrofolate Reductase
- EHGPRT
- FAmidophosphoryl Transferase ATase = glutamine PRPP amidotransferase
- GI should probably know all of these
19Why do we use "De Novo" instead of saying from scratch?
- ABecause Carl Sagan's famous Apple Pie from scratch comment makes it too awesome to use in any setting other than musing about the universe
- BBecause De Novo is more descriptive
- CTo confuse those who are sadly lacking in medical jargon
- DBecause fancy language is awesome
Información
- Descripción
- CMB Final Test sobre Purines and Pyrimidines , creado por Peter Seymour el 18/09/2014.
- Autor
- Peter Seymour
- Idioma
- English
- Visitas
- 228
- Etiquetas
- Valoración
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