BILD 1							Dr. Nigel Crawford
Winter 1997						Due: Tu, March 4, 1997
PROBLEM SET # 5

1.	How were the radioisotopes 35S, 32P and 15N used to show that DNA 
is the genetic material and is replicated semiconservatively?

2. 	If you used ddATP (dATP lacking a 3'-hydroxyl group) instead of 
dATP to synthesize DNA with DNA polymerase, what would happen to the 
reaction?

3.	One amino acid is always found at the end of a newly synthesized 
protein.  Which one is it, which end of the protein is it found, and what is 
its codon?

4.	What are the three major steps in transcription?  What enzyme and 
DNA element are needed in the first step?  What happens in the second 
and third steps?

5.	Compare and contrast a prokaryotic and a eukaryotic mRNA.  There 
are at least four major differences.

6.	Provide the name and function of the three main RNA polymerases 
in eukaryotes.

7.	Why is the genetic code made of triplets (3 nucleotides) and not just 
of two nucleotides?  What do the triplets code for (be sure to describe the 
exceptional ones)?

8.	List the steps of translation starting from a newly made mRNA to 
production of the final protein.

9.	How many tRNA molecules would a ribosome bind and release to 
produce a polypeptide containing 120 amino acids (assume that a given 
tRNA is used only once)?