Problem Set 4: DNA and RNA

General Instructions

1. This is a group activity. 
2. Answer the problems shown below.
3. Submit your answers in pdf/jpg formats only following the naming, Chem40_PS4_<Section>_<Group No.>
4. Only one submission per group is needed. 

Problems

1. What is the structural difference between ATP and dATP?
2. Give the sequence on the opposite strand for pACGTAT, AGATCTp and pATGGTA. Indicate directionality. Are these sequences part of DNA or RNA?
3. In what naturally occurring nucleic acids would you expect to find A-form, B-form, Z-form helices, nucleosomes, and circular DNA?
4. One of the original structures proposed for DNA had all the phosphate groups positioned at the center of a long fiber. Give a reason why this proposal was rejected.
5. Why does DNA with a high A-T content have a lower melting temperature (Tm) than DNA with a high G-C content? Melting temperature means the temperature at which the DNA strands separate.
6. Would you expect tRNA or mRNA to be more extensively H bonded? Why?
7. Would you expect mRNA or rRNA to be degraded more quickly in the cell? Why?
8. Which would be more harmful to the cell, a mutation in DNA or a transcription mistake that leads to an incorrect mRNA? Why?

Questions for fun (not required, if you’re only interested):

• What do you think are the legal and ethical considerations involved in human gene therapy?
• A biomedical company talked about a future in which every individual would have a card that told his or her complete genotype. What would be some advantages and disadvantages of this?
• What can you say about the nature vs nurture concept? You can check out the movies, Gattaca (1997) and The Boys from Brazil (1976)