so in this case here let's look at certain types of ways where the questions can be asked okay for transcription and translation as you can see I've included something referred to as the MRNA table the MRNA table is sometimes given in the exam or they'll give you a simplified version of this in the exam the MRNA table basically tells you which codons will translate to which amino acids for example as you can see Aug they've highlighted it in green okay the AUG is highlighted because it's a start codon and it translates into the amino acid called methionine which is shortened into met if you notice there are certain parts of the table where they've highlighted three codons in red UAA UAG and UGA codons and these translates into the Stop codon because they will terminate the process of translation without wasting time let's look at the question okay let me draw out a gene over here remember the gene is made up of double strands where it's non-template and template and on the template strand I've given you a sequence which is t a c a a t c t g a t and ATC now remember when transcription happens which strand is chosen is it that none template strand or the template strand yes it has to be the template strand so let's form the complementary base pairings for the MRNA notice when the sequence is Tac the RNA has to be Aug not a t g because remember R and A's do not have time in they have uracil instead so I'm putting on all the sequence of the MRNA for you a g a C U A and also u g sorry u a g okay now they will then form the MRNA and if you notice the MRNA they will then have codons of Aug uu a-g-a-c-u-a and u a g so there are five codons in total now so if the first codon is Aug the TRNA has to be an anticodon of UAC and the TRNA will carry an amino acid called methionine I've consulted the table okay let's look at the second one the codon is uu the TRNA has to have an anticodon of AAA right because of complementary based spelling let's consult the table uu anticodons which amino acid does it translate to it translates to an amino acid called phenylalanine which is phe next codon okay AGA if we consult the table it's amino acid alginine next codon CUA tlnase g a u and the amino acid is leucine and UAG translates to a stop codon and there you go you got a polypeptide chain consisting of four amino acids this is how transcription and translation plays out and you can consult the table for this right let's look at another one okay I'm going to change it a little bit all right I'm going to change a sequence over here now let's let's make it a little bit more interesting now let's say that I'm just highlighting I put question marks over that I've put question marks in the gene I've put question marks in the MRNA and I've also put a question mark on the amino acid now let's say the trnas anticodon is CCU all right so we can use the trnx information to find out all the other information right what do I mean by that so if the tiones anticodon is CCU the anticode are the codons of the MRNA has to be GGA and if you look at the table GGA will translate to an amino acid called glycine gly okay and if the MRNA is GGA what will the gene be then well because the mrnase codon was GGA so therefore the gene has to be c c t so by just giving you one information we can kind of piece out all the other informations as well let's try another one okay let's let's for the fun of it just try another one out okay oh there's another thing that we have also have to know about DNA the DNA code is degenerate now what do I mean by degenerate it means that multiple bases can be translated into the same amino acid now what do I mean by that let's try one let's say the genius t a c g c t g c g g c a and act so the MRNA is going to be aug CGA cgc cgu and UGA now interestingly the first TRNA is going to be carrying methionine but the second third and fourth TRN is if you notice they are all carrying the same amino acid arginine because multiple codons can translate to the same amino acid for example the codons CGA codons cgc and codons cgu will all translate into the amino acid arginine so multiple codons can be translated over there as I've highlighted in the table so as you can see in the table where I've just put it like pink squares is it pink yeah I think it's pink you notice that six codons can translate into the amino acids Arginine this is what is meant by the DNA code is degenerate which means to say it can be repetitive basically