The DNA phage QX174 was found to have a ratio of bases of 25A:33T:24G:18C. This departs from the usual A/T = 1 and G/C = 1. How can you explain this observation?
b. Phage P1 has double stranded DNA with 91,500 base pairs (91.5 Kb)
i. Approximately how many double-helical turns does this DNA contain?
ii. How many amino acids can be coded by this DNA? What is the molecular weight of the expected polypeptide in kilodaltons? (One amino acid has a molecular mass of 100 daltons)
iii. What is the molecular weight of this DNA? (Assume that the average base pair weighs 660 Daltons).
iv. If P1 phage original DNA is labelled with 15N and transferred to 14N medium to grow for six generations, What % of the DNA strands will be labelled with 15N if DNA replication is semiconservative.
c. In DNA denaturation and renaturation, what is a Cot curve and what factors influence the renaturation efficiency of DNA? Draw a DNA melting curve, label the axes, and point out the Tm. What are the factors that would influence the T m of your hypothetical DNA
The DNA phage QX174 was found to have a ratio of bases of 25A:33T:24G:18C. This departs from the usual A/T = 1 and G/C = 1. How can you explain this observation?
b. Phage P1 has double stranded DNA with 91,500 base pairs (91.5 Kb)
i. Approximately how many double-helical turns does this DNA contain?
ii. How many amino acids can be coded by this DNA? What is the molecular weight of the expected polypeptide in kilodaltons? (One amino acid has a molecular mass of 100 daltons)
iii. What is the molecular weight of this DNA? (Assume that the average base pair weighs 660 Daltons).
iv. If P1 phage original DNA is labelled with 15N and transferred to 14N medium to grow for six generations, What % of the DNA strands will be labelled with 15N if DNA replication is semiconservative.
c. In DNA denaturation and renaturation, what is a Cot curve and what factors influence the renaturation efficiency of DNA? Draw a DNA melting curve, label the axes, and point out the Tm. What are the factors that would influence the T m of your hypothetical DNA
