Protein synthesis, DNA translation, m-RNA transcription


This animation demonstrates how the
digital information encoded within DNA is used to direct protein synthesis. This is a DNA double-helix
containing the digital code which directs the cell in all aspects of
operation. And here we see a protein complex called
an RNA polymerase travelling down the DNA strand. As it moves down the strand it carefully
unwinds the DNA preparing it for transcription. Inside the polymerase we see a single-stranded copy of the
original instructions being assembled as individual bases are positioned and added
to the growing strand. A stop code marks the end of the
protein specification at which point this copy, known as a messenger RNA transcript, exits the polymerase and heads towards a two-part
chemical manufacturing machine called the ribosome. While the messenger RNA moves towards
the ribosome, transfer RNA molecules attach to specific amino
acids in preparation for assembly. As the messenger RNA transcript
passes through the ribosome the process of translation begins. Using the instructions encoded on the
messenger RNA as a template, the transfer RNA molecules allign specific sequences of bases to
corresponding amino acids creating a protein chain. As this chain exits the ribosome it is
met by chaperones which prevent premature folding while escorting the
protein to a barrel-shaped machine called a chaperonin. This machine helps fold the protein into
the precise shape required to perform its function. Although it is unclear how the chaperonin
achieves this, we do know that accurate folding is essential, in order for the protein to accomplish
its intended function. Once the protein is complete it is released into the cytoplasm to do
its job.

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