Problem 1
What are the four nitrogenous bases found in RNA?
a. Cytosine, guanine, thymine, uracil (C, G, T, U)
b. Adenine, cytosine, guanine, thymine (A, C, G, T)
c. Adenine, cytosine, guanine, uracil (A, C, G, U)
d. Alanine, cysteine, glycine, threonine (A, C, G, T)
Problem 2
What determines the primary structure of a DNA molecule?
a. Stem-and-loop configuration
b. Complementary base pairing
c. Deoxyribonucleotide sequence
d. Hydrophobic interactions and hydrogen bonding
Problem 3
Evaluate the following statements related to the synthesis of nucleic acids. Select True or False for each statement.
T/F Ribonucleotides are added to the 3′ end of a DNA strand.
T/F Polymerization of nucleic acids occurs by the formation of phosphodiester bonds.
T/F Complementary pairing between sugars is required for copying nucleic acids.
T/F Strands in a double helix are synthesized in an antiparallel orientation.
Problem 4
Single strands of nucleic acids are directional, meaning that there are two different ends. What functional groups define the two different ends of a strand?
Problem 5
What is responsible for the increased stability of DNA compared to RNA?
Problem 6
If nucleotides from the DNA of a human were quantified and 30 percent of them contained the base adenine, what percentage of them would contain the base guanine?
a. 20 percent
b. 30 percent
c. 40 percent
d. 70 percent
Problem 7
What would be the sequence of the strand of DNA that is made from the following template: 5′-GATATCGAT-3′? (Your answer must be written 5'→3'.) How would the sequence be different if RNA were made from this DNA template?
Problem 8
According to the RNA world model, a ribozyme would replicate by creating a double-stranded RNA intermediate. Would you expect the intermediate to have the same catalytic activity as the original ribozyme? Justify your answer with an explanation.
Problem 9
Make a concept map that relates DNA's primary structure to its secondary structure. Your diagram should include deoxyribonucleotides, base-stacking interactions, purines, pyrimidines, phosphodiester linkages, DNA's primary structure, DNA's secondary structure, complementary base pairing, and antiparallel double helix.
- In the field of nanotechnology, DNA is used like Velcro to assemble tiny particles into structures that are < 0.0001 mm in size. Draw a model to illustrate how two particles (a circle and a square) could be brought together by linking them to short single-stranded DNA molecules. If the DNA sequence linked to the circle is GGATC, then provide the sequence linked to the square and identify the 5′ and 3′ ends of each strand.
Problem 10
Ch.4 - Nucleic Acids and the RNA World
