Chapter 4 Study Guide: Nucleic Acids
What are the three basic parts of a nucleic acid?
What is a phosphodiester linkage? By what type of reaction is it formed? Does this reaction result in
an increase or decrease in entropy? Why?
What is the basic difference between RNA and DNA from a sugar backbone standpoint? How does
this affect their reactivities? From an evolutionary standpoint, why is this important?
Does a strand of nucleic acid have directionality? Why?
From a nitrogenous base standpoint, what is/are the difference(s) between the basic structures of
RNA and DNA?
What is the “backbone” of a strand of DNA or RNA composed of?
What does it mean to say that a nucleic acid has become activated? Why is this important?
How was X-ray crystallography used to determine the structure of DNA? (Hint: See Bioskills 8 in the
back portion of the textbook)
Who determined the secondary structure of DNA?
What three pieces of information did the researchers who determined the secondary structure of
DNA have at their disposal?
What are Chargaff’s rules? What two concepts in the secondary structure of DNA can you relate them
to?
What determines the secondary structure of DNA? (Hint: what molecular interactions bind the two
strands together?)
What does it mean to say that “DNA is an information containing molecule”
How is a copy of a DNA molecule made? (Hint: what happens to the individual strands?)
Regarding RNA structure, what is a hairpin? What two simpler structures make up a hairpin? Why do
these form?
What does the phrase “complementary base pairing” refer to when discussing secondary structure of
DNA? Why are the two DNA strands antiparallel?
Adenine pairs with __________.
Cytosine pairs with __________.
In an RNA molecule uracil pairs with _________ because _________ is absent in RNA.
