Quick Biochemistry - Nucleic Acids (Section 6)

• 1

  Which of the following is NOT a characteristic of orotic aciduria?

  回答

  (A)

  Enhanced production of pyrimidine nucleotides
• 2

  A genetic lack of adenosine deaminase leads to

  回答

  (C)

  Weakened immune system
• 3

  A total lack of hypoxanthine guanine phospharibosyl transferase results in

  回答

  (D)

  Lesch-Nyhan syndrome
• 4

  Increased excretion of orotic acid in urine can be caused by a deficiency in

  回答

  (D)

  Any of the options listed
• 5

  Which of the following is NOT a typical symptom of Lesch-Nyhan syndrome?

  回答

  (C)

  Delayed growth
• 6

  A hereditary deficiency in purine nucleoside phosphorylase is most likely to cause

  回答

  (C)

  Immune system problems
• 7

  Deoxyribonucleotides are produced through the reduction of

  回答

  (C)

  Ribonucleoside diphosphates
• 8

  What other compound can orotate phosphoribosyl transferase use?

  回答

  (D)

  Adenine
• 9

  Why is gout less common in mammals other than higher primates?

  回答

  (D)

  They have uricase enzyme
• 10

  Low levels of uric acid can occur in individuals with

  回答

  (A)

  Xanthine oxidase deficiency
• 11

  The process of creating a DNA copy is also termed

  回答

  (B)

  Replication
• 12

  The method by which DNA is replicated is described as

  回答

  (B)

  Semi-conservative
• 13

  In what direction is new DNA generally assembled

  回答

  (A)

  5' to 3'
• 14

  In the DNA synthesis process, what usually comes before

  回答

  (A)

  Replication
• 15

  Short segments found in DNA replication consist of

  回答

  (C)

  Both RNA and DNA
• 16

  Which of the following molecules has its assembly that results in Okazaki fragments

  回答

  (D)

  DNA
• 17

  When the replication fork appears

  回答

  (B)

  One strand is made continuously, the other with breaks
• 18

  About how many units make up one Okazaki fragment

  回答

  (C)

  1,000 Units
• 19

  Which enzyme is responsible for creating the RNA primer

  回答

  (B)

  Primase
• 20

  In RNA, what base pairs with adenine

  回答

  (D)

  Uracil
• 21

  In the process of duplication, where does the original DNA strand separate?

  回答

  (C)

  At several locations
• 22

  In DNA replication, what molecule initiates the separation of the double helix?

  回答

  (B)

  DnaB protein
• 23

  To separate the double-stranded DNA, what is needed?

  回答

  (A)

  Energy from ATP
• 24

  What action do helicase and DnaB protein perform?

  回答

  (C)

  Unwinding DNA and requires ATP
• 25

  After the DNA strands separate, how are they kept apart?

  回答

  (A)

  Single strand binding protein
• 26

  What enzyme adds deoxyribonucleotides to the RNA primer?

  回答

  (C)

  DNA polymerase III holoenzyme
• 27

  Which enzyme replaces the RNA primer's ribonucleotides with deoxyribonucleotides?

  回答

  (A)

  DNA polymerase I
• 28

  What is used to join DNA fragments together?

  回答

  (B)

  DNA ligase
• 29

  What introduces negative supercoils into the DNA structure?

  回答

  (C)

  DNA gyrase
• 30

  Which of the following contains reverse transcriptase activity in eukaryotic cells?

  回答

  (C)

  Telomerase
• 31

  What function does the DNA polymerase III holoenzyme perform?

  回答

  (D)

  3'→5' Exonuclease and polymerase activities
• 32

  What is a characteristic function of DNA polymerase I?

  回答

  (D)

  All of these
• 33

  What is the role of the 3'→5' Exonuclease activity of DNA polymerase I?

  回答

  (C)

  Corrects errors in replication
• 34

  Which of the following statements about RNA-dependent DNA polymerase is incorrect?

  回答

  (D)

  It is present in all the viruses
• 35

  What reaction does reverse transcriptase facilitate?

  回答

  (C)

  Synthesis of DNA
• 36

  What type of DNA does the DNA A protein specifically bind to?

  回答

  (B)

  Negatively supercoiled DNA
• 37

  What reaction does DNA topoisomerase I of E. coli catalyze?

  回答

  (A)

  Relaxation of negatively supercoiled DNA
• 38

  During which phase of the mammalian cell cycle does DNA synthesis take place?

  回答

  (A)

  S phase
• 39

  At what temperature does the melting of DNA occur?

  回答

  (D)

  Native double helical DNA is denatured
• 40

  What factor increases the melting temperature of DNA?

  回答

  (B)

  G and C content
• 41

  The factor that enhances the buoyant density of DNA is related to its

  回答

  (B)

  Guanine and Cytosine base composition
• 42

  The ratio of Guanine and Cytosine to Adenine and Thymine within DNA can be calculated by examining its

  回答

  (C)

  Both methods
• 43

  Mitochondria in certain cell types contain some amount of DNA in

  回答

  (B)

  More complex cells
• 44

  Which characteristic is observed in satellite DNA?

  回答

  (A)

  Highly recurring sequences
• 45

  What is the process of creating RNA using a DNA blueprint called?

  回答

  (C)

  RNA creation
• 46

  In which direction is RNA generally synthesized?

  回答

  (A)

  Five prime to three prime
• 47

  DNA-dependent RNA polymerase has how many protein subunits?

  回答

  (D)

  Four
• 48

  For effective operation, DNA-dependent RNA polymerase requires

  回答

  (C)

  Either ion
• 49

  Which element identifies the transcription starting point?

  回答

  (C)

  Sigma factor
• 50

  The location where transcription concludes is determined by

  回答

  (D)

  Rho factor