Module 5 Exam
Questions and Complete
Solutions Graded A+
Denning [Date] [Course title]
,purines - Correct Ans: have a double ring structure with a six-membered ring fused to a five-membered
ring.
Pyrimidines - Correct Ans: have a single six-membered ring structure.
5'-3' phosphodiester bonds - Correct Ans: DNA nucleotides that are part of a polynucleotide chain have
one phosphate residue attached to the hydroxyl group of the 5' carbon of one sugar of one nucleotide
and the hydroxyl group of the 3' carbon of the sugar of the next nucleotide.
dNMPs - Correct Ans: nucleotides that are part of a polynucleotide chain and called collectively
deoxynucleoside monophosphates where N can refer to any of the four nucleotide bases.
dNTPs - Correct Ans: free reactive DNA nucleotides called deoxynucleotide triphosphates that are not
part of a polynucleotide chain carry a string of three phosphate groups at the 5' carbon
DNA polymerase - Correct Ans: catalyzes the formation of a phosphodiester bond between the 3'
hydroxyl group of one nucleotide and the 5' phosphate group of an adjacent nucleotide.
sugar-phosphate backbone - Correct Ans: alternating sugar and phosphate groups throughout a
polynucleotide chain
antiparallel orientation - Correct Ans: 3' end of one strand faces the 5' end of the other strand so that
the partial charges of complementary nucleotides come into alignment to form hydrogen bonds.
hydrogen bond - Correct Ans: A type of weak chemical bond formed when the slightly positive hydrogen
atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar
covalent bond in another molecule.
3.4 angstroms - Correct Ans: Each base pair nucleotide is separated from the other base pair by a
distance of _______
1 angstrom - Correct Ans: ________is equal to .1 nano meter (nm)
, Major groove - Correct Ans: N7 and C6 groups of purines and the C4 and C5 groups of pyrimidines face
into the ___________
Minor groove - Correct Ans: H-bond donors and acceptors are in the ____________
B-form DNA - Correct Ans: is the most common and stable in which molecular configuration spirals to
the right
A-form DNA - Correct Ans: compact with about 11 base pairs per complete helical twist and a higher
degree of tilt of the base pairs relative to the backbone. Found in dehydrated samples.
Z-form DNA - Correct Ans: a rarer Left-handed helical structure found in DNA bound to certain proteins.
Chargaff's Rules - Correct Ans: DNA from any cell of all organisms should have a 1:1 ratio (base pair rule)
of pyrimidine and purine bases specifically that the amount of G is equal to C and the amount of A is
equal to T.
semi-conservative - Correct Ans: each of the two parental DNA strands acts as a template for new DNA
to be synthesized; after replication, each double-stranded DNA includes one parental or "old" strand
and one "new" strand.
bidirectional - Correct Ans: DNA replication is ___________ meaning progressing in both directions.
origins of replication - Correct Ans: particular positions in chromosomes where specialized initiator
proteins bind to DNA to start the process of replication.
Bacterial chromosomes - Correct Ans: contain only one single origin of replication
eukaryotic chromosomes - Correct Ans: contain multiple origins of replication
eukaryotes - Correct Ans: Multiple origins are necessary in _________ because they have much larger
genomes and replication forks move slower.