Consider the biomolecule below:
Chemical structure of a relevant biomolecule.
Neatly draw this molecule. Name this molecule. Correctly number all of the carbon atoms in this molecule. Is the molecule a nitrogenous base, a nucleoside, a nucleotide, or a nucleic acid? List three chemical differences between this molecule and the compound thymidine.
In double helical DNA the nitrogenous base cytosine pairs with guanine. Draw the cytosine-guanine base pair. Draw the hydrogen bonds and number the atoms in your structure.
Imagine that you have just purified a new plasmid DNA from E. coli bacteria. You wish to map the restriction sites so you digest the DNA with various restriction endonucleases and measure the resulting sizes of the cut DNA by agarose gel electrophoresis. Construct a restriction map for a circular plasmid DNA from the following gel data:
Schematic image of agarose gel electrophoresis separation of DNA fragments.
First, fill out the following table with the sizes of the bands in each lane:
Restriction endonuclease Fragment sizes (kilobases)
EcoRI and HaeII
EcoRI and PstI
HaeII and PstI
Now, write the total number of bases in the center of the circle below and mark the relative positions of the restriction enzyme recognition sites. Label the distance between all of the sites in kilobases.
Schematic map of DNA plasmid for restriction mapping.
Polymerase chain reaction (PCR) allows for replication of double-stranded DNA between two single-stranded oligonucleotide primers. Assuming perfect doubling with each cycle, calculate the theoretical final concentration after 40 cycles of PCR from a single molecule of double-stranded DNA in a 0.1 mL volume.