|
Explanation: From
the template strand given in the box, build a strand of pre-mRNA. The
nucleotide triphosphates used to build the mRNA strand are available
in the cell, and the
condensation reaction that joins them to the
existing strand is catalyzed by an RNA polymerase enzyme. The energy
to drive this condensation reaction is derived from the
hydrolysis of
the nucleotide triphosphate when the bonds linking two of the
phosphate groups are broken. The third phosphate group remains
attached to the nucleotide and becomes part of the
phosphodiester linkage that holds the nucleic acid together. This transfer of energy
is an example of
substrate-level phosphorylation.
Pay special attention to base pairing and to building the RNA strand
from the 5’ to the 3’ end. When you have attached a nucleotide
correctly, you will see energy released by the removal of the two
phosphate groups and the formation of the phosphodiester linkage via a
condensation reaction (symbolized by a water drop). You will also see
the
hydrogen bonds that form between the paired bases.
|
|
Transcribe DNA |
|
Drag and drop the
nucleotides
provided to the correct locations on the DNA template strand
to transcribe DNA.
When SUCCESS! appears
on the screen, you have successfully formed an RNA
transcript from the original DNA. |
|
