Quick Biochemistry - Nucleic Acids (Section 1)

  • 1
    What components combine to form a nucleoside?
    Răspuns
    (B)
    A purine or pyrimidine base and a sugar
  • 2
    Which of the following best describes the composition of a nucleotide?
    Răspuns
    (B)
    A purine and pyrimidine base, a sugar, and phosphorous
  • 3
    Which of the following is classified as a purine nucleotide?
    Răspuns
    (A)
    AMP
  • 4
    Which option represents a pyrimidine nucleotide?
    Răspuns
    (C)
    CMP
  • 5
    Adenine is also known as:
    Răspuns
    (A)
    6-Amino purine
  • 6
    What is the other name for 2, 4-Dioxypyrimidine?
    Răspuns
    (C)
    Uracil
  • 7
    What is the chemical designation for guanine?
    Răspuns
    (B)
    2-Amino-6-oxypurine
  • 8
    In what units are the concentrations of nucleotides and nucleic acids frequently expressed?
    Răspuns
    (D)
    OD at 260 nm
  • 9
    Which pyrimidine nucleotide is involved in high-energy intermediate reactions?
    Răspuns
    (C)
    UDPG
  • 10
    In a nucleotide, what carbon position on the pentose molecule is involved in an ester bond with phosphate?
    Răspuns
    (D)
    C₅
  • 11
    What molecule results from the combination of uracil and ribose?
    Răspuns
    (A)
    Uridine
  • 12
    Which nucleotide is most prevalent in a free state within animal cells?
    Răspuns
    (A)
    ATP
  • 13
    Approximately what is the average intracellular concentration of ATP in a mammalian cell?
    Răspuns
    (A)
    1 mM
  • 14
    Which base is present in messenger RNA but absent in deoxyribonucleic acid?
    Răspuns
    (D)
    Uracil
  • 15
    What is the function of 'Caps' in an RNA molecule?
    Răspuns
    (B)
    Are unique to eukaryotic mRNA
  • 16
    How does prokaryotic mRNA differ from eukaryotic mRNA?
    Răspuns
    (A)
    Can be polycistronic
  • 17
    What is the approximate size range of small stable RNA molecules?
    Răspuns
    (C)
    90-300 nucleotides
  • 18
    What is the approximate range of small stable RNAs found within a single cell?
    Răspuns
    (C)
    1,00,000-10,00,000
  • 19
    What is the approximate molecular weight of heterogenous nuclear RNA (hnRNA)?
    Răspuns
    (A)
    More than 107
  • 20
    In RNA, why isn't the guanine content always equal to cytosine, and adenine always equal to uracil?
    Răspuns
    (A)
    Single strand molecule
  • 21
    Which nitrogenous base is found in RNA?
    Răspuns
    (B)
    Uracil
  • 22
    Which of the following is NOT a component of RNA?
    Răspuns
    (C)
    Thymine
  • 23
    What type of sugar is found in RNA?
    Răspuns
    (C)
    Ribose
  • 24
    Which statement accurately describes base pairing in an RNA molecule?
    Răspuns
    (D)
    Guanine content does not necessarily equal its cytosine content.
  • 25
    In which type of RNA are methylated purines and pyrimidines typically found?
    Răspuns
    (C)
    tRNA
  • 26
    Where is Thymine typically found?
    Răspuns
    (A)
    tRNA
  • 27
    What is the approximate number of nucleotides in a tRNA molecule?
    Răspuns
    (C)
    75
  • 28
    In a typical cell, what is the minimum number of different tRNA molecules present?
    Răspuns
    (B)
    20
  • 29
    What shape does a tRNA molecule resemble?
    Răspuns
    (C)
    Clover leaf
  • 30
    In tRNA molecules, the CCA sequence is always located at the:
    Răspuns
    (A)
    3' Termini
  • 31
    What is the basis for classifying Transfer RNAs?
    Răspuns
    (D)
    Extra arm
  • 32
    Which modified base is found in the D arm of a tRNA molecule, giving it its name?
    Răspuns
    (A)
    Uridine
  • 33
    How many base pairs are typically found in the acceptor arm of a tRNA molecule?
    Răspuns
    (B)
    7 Base pairs
  • 34
    How many base pairs does the anticodon arm of a tRNA molecule typically possess?
    Răspuns
    (A)
    5 Base pairs
  • 35
    What sequence is typically found in the TΨC arm of a tRNA molecule?
    Răspuns
    (A)
    T, pseudouridine and C
  • 36
    Who put forth the double helical structure model of DNA?
    Răspuns
    (C)
    Watson and Crick
  • 37
    Which of the following is NOT found in DNA?
    Răspuns
    (C)
    Uracil
  • 38
    What is the type of sugar molecule found in DNA?
    Răspuns
    (A)
    Deoxyribose
  • 39
    DNA segments with a high concentration of A-T pairs are stabilized by how many hydrogen bonds?
    Răspuns
    (B)
    2 Hydrogen bonds
  • 40
    Which statement accurately describes the base composition in a DNA molecule?
    Răspuns
    (D)
    Guanine content equals cytosine content
  • 41
    DNA with a high proportion of G-C pairs tend to have what characteristic regarding hydrogen bonds?
    Răspuns
    (C)
    3 Hydrogen bonds
  • 42
    Given that DNA carries an organism's genetic code, what can be logically inferred about its base composition across different tissues?
    Răspuns
    (C)
    DNA from different tissues in the same organism should usually have the same base composition
  • 43
    What is the approximate width of the B-form DNA double helix in nanometers?
    Răspuns
    (B)
    2
  • 44
    How many base pairs are typically found in a single complete turn of the B-form DNA molecule?
    Răspuns
    (C)
    10
  • 45
    What is the distance, in nanometers, covered by one full turn of B-form DNA?
    Răspuns
    (D)
    3.4 nm
  • 46
    If the thymine concentration in a DNA molecule is 30%, what is the predicted concentration of guanosine?
    Răspuns
    (B)
    20%
  • 47
    If the guanosine content in a DNA molecule is 40%, what would be the percentage of adenine?
    Răspuns
    (A)
    10%
  • 48
    What factor leads to a higher melting temperature in duplex DNA?
    Răspuns
    (C)
    Cytosine + Guanine
  • 49
    What condition is often treated with the synthetic nucleotide analogue, 4-hydroxypyrazolopyrimidine?
    Răspuns
    (B)
    Gout
  • 50
    Which synthetic nucleotide analogue is frequently used in cancer and viral infection treatment?
    Răspuns
    (A)
    Arabinosyl cytosine