Codons for Amino Acids Video Lecture - Biology Class 12 - NEET

in a second year we'll get to the bottom
of what a codon is but in order to start
out we're going to start with us
something a little bit simpler here on
on the screen I have a big string of RNA
this is RNA and RNA is the code that
creates proteins inside organisms a big
string of RNA just might look like this
a big gobbledygook of a whole bunch of
different letters but RNA is actually
organized into groups of three like this
and we call each group of three a codon
and actually what these are groups of is
each individual one of these letters is
called a nucleotide nucleotide and so a
group of three nucleotides is called a
codon and what each of these codons do
is each of these codons codes for an
amino acid so Aug here codes for an
amino acid amino acid one I'll just put
a one here with each of these codons
coding for a different amino acid what
happens is all the codons put together
code for a protein a protein protein
alright so all of the amino acids put
together create a protein and here this
is amino acid number seven output amino
acid here so that you can remember that
each codon codes for an amino acid one
other thing that's really important to
remember about RNA here is that because
these seven codons put together create a
protein it's
really important for RNA to know when
the beginning of a protein starts and
when the end of the protein is reached
and so the beginning here and the end of
these proteins are need to be signaled
and how codons and RNA do this is they
have soon certain Universal amino acids
certain codons here excuse me
certain codons that code for a protein
to start and for a protein to stop and
so here at the end here this is a stop
codon that says hey this is the last
codon you can end here and finish off
the protein so you AG that's a stop
codon and at the beginning of our list
here we have a start codon Aug says hey
this is the beginning of the code for a
protein I am a start codon so Aug is a
start codon and UAG is a stop codon