Tutorial Practice Questions - Week 2 Flashcards
Polynucleotide chains have a 5’ & 3’ end. Which groups are found at each of these
ends?
a) 5’ sugars, 3’ phosphates
b) 3’ OH, 5’phosphates
c) 3’ base, 5’phosphates
d) 5’phosphates, 3’ OH
d
How many phosphates can a nucleotide have?
1, 2 or 3 phosphates
What distinguishes nucleotides from nucleosides?
a) Nucleosides lack the sugar group.
b) Nucleosides lack the phosphate group.
c) Nucleosides lack a nitrogenous base.
b
Can nucleotides exist in a monomeric from?
Yes. Nucleotides can exist as separate entities. E.g. ATP (energy)
DNA contains many hydrogens bonds.
a) Are hydrogen bonds stronger or weaker than covalent bonds?
b) What are the consequences of this difference in strength?
weaker
Strong enough to hold complementary strands together but can be easily
broken by enzymes or temperature to facilitate functional activities such as
replication, or transcription.
What is the function of a DNA polymerase?
a) It degrades DNA in cells
b) It adds RNA nucleotides to a new strand
c) It coils DNA around histones to form chromosomes
d) It adds DNA nucleotides to a replicating new strand
d
The nucleotide sequence of DNA is which level of structure: primary, secondary,
tertiary, or quaternary?
Primary
Which one is true about structural differences between RNA and DNA
a) Bases, pentose, and the phosphodiester linkage
b) Bases, pentose, and the secondary structure
c) Bases, pentose, and the glycosidic bond
b
In eukaryotes, DNA is wrapped around
a) Single-stranded binding proteins
b) Polymerases
c) Ribosomes
d) Histones
d
mRNA splicing is required to remove _____ from pre-mRNA and initiate ______
a) Introns, translation
b) Exons, transcription
c) Exons, translation
d) Introns, transcription
a
T/F: The synthesis of a polypeptide chain occurs in the cytoplasm and involves direct
interactions between DNA, mRNA, tRNA and amino acids.
False (DNA is not in the
cytoplasm, and it is not directly involved in the synthesis of a polypeptide chain)
T/F: tRNA contains double-stranded portions, a codon, and the respective amino acid.
False (tRNA has an anticodon: sequence of 3 bases that are complementary to the
codon in the mRNA sequence)
T/F: More than one codon can code for the same AA.
True
(Redundancy)
T/F: A mature mRNA transcript with 300 nucleotides codes for a sequence of 30 amino
acids.
False (3 nucleotides code for 1 amino acid; therefore, 300 nucleotides code for
100 amino acids).
T/F: The synthesis of a polypeptide chain is initiated by a starting codon, AUG, which
codes for the amino acid Methionine (Met).
True
