Welcome back to the second of the two lectures
looking at gene structure, expression, and regulation.
This time we'll look at the translation of messenger RNA
and the regulation of gene expression.
This is the second lecture looking at the central dogma of molecular biology.
Last time, we considered the processes of DNA replication and the flow of
information from DNA to RNA through messenger RNA transcription,
two processes that occur in the nucleus.
This time, we should consider the final element in
the flow of information from RNA to protein,
which occurs in the cytosol.
Translation from messenger RNA to protein involves messenger RNA, the ribosome,
which is a two subunit structure where each subunit is a complex of RNA and proteins.
This reads the sequence of the messenger RNA molecule as it is translated into protein,
and transfer RNAs which are important for the delivery
of the correct amino acid in the sequence translation.
The ribosome in eukaryotic cells comprises of a large subunit and a small subunit,
called the 60S and 40S subunits, respectively.
The 60S subunit contains three ribosomal RNA species: 28S, 5.8S, and 5S.
Plus, 47 proteins, labeled RP,
ribosomal protein, and L for large,
numbers 1 through to 47.
The 40S subunit has only one ribosomal RNA, the 18S subunit.
Plus 33 ribosomal proteins labeled S for small,
1 through to 33.