questions for amino acids and nucleotide biosynthesis

1. Which chemical reaction depicts nitrification?
A. N₂ ® NH₄⁺
B. NO₃^- ® NH₄⁺
C. NO₂^-® NO₃^-
D. NO₃^- ® N₂

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2. Glutamine is derived from which glycolysis or citric acid cycle intermediate?
A. pyruvate
B. a-ketoglutarate
C. oxaloacetate
D. 3-phosphoglycerate

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3. Newborn infants sometimes develop jaundice because of an accumulation of
A. heme.
B. biliverdin.
C. urobilin.
D. bilirubin.

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4. In the de novo pathway, what is the immediate precursor to dTMP?
A. dUMP
B. TMP
C. thymidine
D. dCMP

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5. Which of the following is true about the de novo synthesis of nucleotides?
A. Deoxyribonucleotides are precursors of ribonucleotides.
B. Pyrimidines are precursors of purines.
C. Bases are synthesized then attached to ribose or deoxyribose.
D. Amino acids are precursors of nucleotides.

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6. Plants carry out
A. reduction of nitrate.
B. denitrification.
C. nitrification.
D. nitrogen fixation.

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7. Which of the following molecules is not derived from glycine?
A. glutathione (GSH)
B. heme
C. serotonin
D. phosphocreatine

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8. The conversion of serine to glycine requires which of the following?
A. S-adenosylmethionine (adoMet)
B. 5-phosphoribosyl-1-pyrophosphate (PRPP)
C. NADH
D. tetrahydrofolate (H₄ folate)

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9. Nucleoside diphosphate kinase catalyzes which reaction?
A. ATP + AMP 2 ADP
B. ATP + dCDP ADP + dCTP
C. ATP + dGMP ADP + dGDP
D. ATP + UMP ADP + UDP

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10. Adenosine deaminase deficiency leads to
A. gout.
B. Lesch-Nyhan syndrome.
C. severe immunodeficiency disease.
D. porphyria.

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11. Which of the following molecules does not result from decarboxylation of an amino acid?
A. histamine
B. spermidine
C. g-aminobutyrate (GABA)
D. dopa

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12. Which of the following is true about the symbiotic relationship between leguminous plants and nitrogen-fixing bacteria?
A. Leguminous plants produce leghemoglobin to prevent oxygen from interfering with the bacterial electron-transfer system.
B. Nitrogen-fixing bacteria obtain citric acid intermediates from the leguminous plants.
C. Nitrogen-fixing bacteria are present on the leaves of the leguminous plants.
D. Leguminous plants produce the nitrogenase complex used by the bacteria to fix nitrogen.

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13. Chorismate is an intermediate in the synthesis of which amino acid?
A. phenylalanine
B. proline
C. serine
D. cysteine

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14. In the salvage pathway, how are nucleotides generated?
A. Free bases are attached to ribose, which is then phosphorylated to generate the corresponding NMPs.
B. Free bases exchange with the bases on NMPs.
C. Free bases react with 5-phosphoribosyl-1-pyrophosphate (PRPP) to generate the corresponding NMPs.
D. Purine and pyrimidine bases are built up while attached to ribose throughout the process.

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15. Parkinson's disease is associated with
A. an underproduction of dopamine.
B. an underproduction of g-aminobutyrate (GABA).
C. an overproduction of histamine.
D. an overproduction of dopamine.

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16. AMP is converted to adenosine by what enzyme?
A. nucleotidase
B. 5'-nucleotidase
C. adenosine deaminase
D. ribonucleotide reductase

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17. Which of the following occurs in the degradation pathway of AMP?
A. Adenine is converted to hypoxanthine.
B. The end product is urea.
C. AMP is converted to adenosine.
D. Adenosine is converted to adenine.

sources: http://bcs.whfreeman.com/lehninger/pages/bcs-main.asp?v=chapter&s=22000&n=00070&i=22070.01&o=|00510|00520|00530|00540|00550|00PRS