During DNA replication in E. coli, DNA gyrase is an enzyme that helps to unwind the double helix by preventing supercoils from accumulating as the single strands of the double helix are separated. This enzyme is classified as a:

The 3’ ends of eukaryotic mRNAs are modified by the addition of 100-200 nucleotides with only adenine bases.  The enzyme that adds this “poly(A) tail” is:

In the genetic code, code words that are three bases long can specify 4 x 4 x 4 = 64 amino acids, because there are 4 possibilities (A, U, C, G) for each of the three positions. If there were only 2 bases (A and U, or G and C), the code words would have to be how many bases long to code for all 20 amino acids?

Which of the following are protein subunits of a eukaryotic DNA polymerase that synthesizes much of the DNA in eukaryotic cells?

What is the role of the DnaC and DnaT proteins in DNA replication in E. coli?

Relatively large regions of damaged DNA are repaired by a mechanism that cuts the DNA backbone in two locations and removes the damaged region.  In prokaryotes, a segment 12 or 13 nucleotides is removed; in eukaryotes, 27 to 29 nucleotides.  DNA polymerase then fills the gap, and DNA ligase covalently closes it.  This DNA repair mechanism is:

Thymine dimers are a type of DNA damage produced when adjacent thymine bases along the same strand of the DNA double helix are crosslinked by UV light. What is the name of the DNA repair mechanism that uses the enzyme photolyase to repair the thymine dimers?

The generation of ATP energy in mitochondria includes a shuttle system that indirectly transports NADH from the cytosol into the mitochondrial matrix. In this shuttle system, an H+ from NADH and a free H+ are linked to __________ to produce __________, which can readily pass through the inner mitochondrial membrane and into the mitochondrial matrix.

How many proteins of human mitochondria are encoded in each of the circular mitochondrial DNA molecules in the mitochondrial matrix? (Mitochondria are composed of over 1000 proteins.)

Scenario 3 [#38 – #44]  What are the significant predictors? (2 points)