Question

1. REPLICATION: The original sequence of DNA on the first strand is:

Complete its complementary anti-sense NEW strand

A T G C G A C C C A A A C C G C A G C A A T T T T T G G G G C T A A T G T A G. TRANSCRIPTION: Take the new strand of DNA and code the messenger RNA that would be created from it: TRANSLATION: The strand of messenger RNA has the following sequence – determine the codons and polypeptide that will be coded on the ribosome with complementary tRNA

Answer 1

@Aaronmd33 here is what you will need to solve the problem:

REPLICATION: Remember that each base pairs with a complementary base --> A-T & C-G, thus if you know the top part of the sequence then you should also know the bottom part...Example:

Top Strand: A T G C...etc
| | | |
T A C G...etc

TRANSCRIPTION: First of all with transcription we must know which strand is the "coding strand", since all peices of DNA have a top and a bottom strand and reading from one or the other would produce different mRNA molecules. In this problem it is telling us that we need to make our RNA from the NEW strand that you created during the replication part (ie: the one that starts with TAG). Making RNA is exactly the same as replicating DNA except instead of Thiamine (T) there is Uracil (U). So in the case of RNA...A pairs with U and C pairs with G...Example:

DNA Strand: A T G C...etc
| | | |
U A C G...etc


TRASLATION: Now we have our mRNA and we want to make a polypeptide. The first step is to look at our mRNA and find the start codon. This is where the mRNA says AUG...Example:

mRNA Strand 5' - accAUGaacaguggcagcuuucga - 3'

In the above example if you count in 3 nucleotides we see that there is an AUG. Now that we have the AUG this is where the protein starts. Now we need to break up the mRNA strand into blocks of 3...Example:

mRNA Strand 5' - accAUG aac agu ggc agc uuu cga - 3'

We dont care about anything before the AUG because that is not part of the "reading frame". Now that we have broken up the mRNA into "triplet codons" we can look at the codon table (see attached), and determine which amino acids are coded for. You keep adding amino acids until you hit a stop codon!

Happy Coding