The following DNA strand is both the CODING strand and a PARENTAL DNA strand: 5\
ID: 92100 • Letter: T
Question
The following DNA strand is both the CODING strand and a PARENTAL DNA strand: 5' C A T G C G A A G C G C C G C C A G T A A A T A A C 3' In the drawing above, complete the other strand of the DNA in the chromosome by writing the corresponding letter of the nucleotide below the parental nucleotide. Directly below the replicated DNA strand, write the transcription product (MRNa) Now, looking at your mRNA transcript, find the start codon and circle it in your transcript. Now that you have identified the start point for translation, re-write the transcript into the right reading frame brakes in the mRNA codon boxes. Use the codon table from your text/notes/PPT to discover the amino acid sequence of the polypeptide and write it in the lowest set of boxes.Explanation / Answer
Ans. Coding strand: 5’-C A T G C G A A G C G C C G C C A G T A A A T A A C-3’
DNA is double stranded. One strand in the gene is called coding strand and the other is called template strand.
RNA polymerase binds to template strand at 3’end and synthesizes mRNA in 5’-3’ direction.
#1. Replicated DNA strand: Replicated DNA strand, which will act as the template DNA strand is antiparallel and complementary to the coding strand.
So, its sequence s –
3’- GTACGCTTCGCGGCGGTCATTTATTG- 5’
#2. mRNA: The sequence and polarity of coding strand and mRNA is exactly the same except T is DNA is replaced by U in mRNA.
So, mRNA sequence is-
5’- CAUGCGAAGCGCCGCCAGUAAAUAAC- 3’
Before translating the mRNA (as you bypassed), the statement 3 says to find and circle the start codon. The start codon is AUG. After start codon is located, write new mRNA transcript starting with AUG start codon in the box in individual codons.
New transcript is- 5’- AUG CGA AGC GCC GCC AGU AAA UAA C- 3’
Note: AUG = start codon , UAA = STOP codon
Using genetic code dictionary, write amino acid sequence from N- to C-terminal. The AA sequence is – N-ter Met-Arg-Ser-Ala-Ala-Ser- C-ter