Exam 9: DNA structure and Analysis

Assume that the molar percentage of thymine in a double-stranded DNA is 20.What are the percentages of the four bases (G,C,T,A)? If the DNA is single-stranded,would you change your answer?

What does it mean to say that double-stranded nucleic acids are antiparallel?

List three forms of DNA.

Name the pyrimidines and the purines in DNA.

In 1953,Watson and Crick published a paper that described the structure of DNA.

In ribose,the 2' C has an OH attached to it.

What is the name of the precursor molecule used in nucleic acid synthesis?

Suppose that the dinucleotide in the accompanying figure were cleaved with the enzyme spleen diesterase,which breaks the covalent bond connecting the phosphate to C-5'.After such cleavage,to which nucleoside is the phosphate now attached?

Avery et al.(1944)determined that DNA is the genetic material in T2 bacteriophage.

What is meant by the term antiparallel?

The transforming principle discovered by Griffith is RNA.

The classic Hershey and Chase (1952)experiment that offered evidence in support of DNA being the genetic material in bacteriophages made use of which of the following labeled component(s)?

Deoxyribonuclease is an enzyme that adds 3'-hydroxyl groups to RNA.

Considering the Central Dogma of Molecular Genetics,what general property is ascribed to DNA?

Present an overview of two classical experiments that demonstrated that DNA is the genetic material.Can RNA be the genetic material? Explain.

If 15% of the nitrogenous bases in a sample of DNA from a particular organism is thymine,what percentage should be cytosine?

Is the accompanying figure DNA or RNA? Is the circle closer to the 5' or 3' end?

The base content of a sample of DNA is as follows: A = 31%,G = 31%,T = 19%,C = 19%.What conclusion can be drawn from this information?

In the 1860s,a Swiss chemist,Friedrick Miescher,isolated an acidic substance from cell nuclei.What was the name of this substance,and what was its significance?

List two major differences between RNA and DNA at the level of the nucleotide.