Can someone please help me with this question, I am confused. Thank you Accordin
ID: 967667 • Letter: C
Question
Can someone please help me with this question, I am confused. Thank you According to the central dogma, double-stranded DNA serves as the template for the production of RNA during transcription. Which of the two DNA strands serves as the template for transcription? Both DNA strands serve as templates simultaneously for RNA polymerase, with continuous transcription on the leading strand and discontinuous transcription on the lagging strand. O Either DNA strand may be used as a template by RNA polymerase, but a single DNA strand oriented in the 3'- 5 direction is used as a template each time transcription occurs. O The DNA strand oriented in the 3-5 direction is the only template because RNA O The DNA strand oriented in the 5-3 direction is the only template because only this strand polymerase synthesizes only in the 3-5' direction contains the promoter sequences necessary to initiate transcriptionExplanation / Answer
Option-2 (Either DNA strand may be used as a template by RNA polymerase, but single DNA strand oriented in the 3’ 5’ direction is used as a template each time transcriptions occurs) is correct.
A DNA transcription unit encoding for a protein may contain both a coding sequence, which will be translated into the protein, and regulatory sequences, which direct and regulate the synthesis of that protein. The regulatory sequence before ("upstream" from) the coding sequence is called the five prime untranslated region (5'UTR); the sequence after ("downstream" from) the coding sequence is called the three prime untranslated region (3'UTR).
As opposed to DNA replication, transcription results in an RNA complement that includes the nucleotide uracil (U) in all instances where thymine (T) would have occurred in a DNA complement.
Only one of the two DNA strands serve as a template for transcription. The antisense strand of DNA is read by RNA polymerase from the 3' end to the 5' end during transcription (3' 5'). The complementary RNA is created in the opposite direction, in the 5' 3' direction, matching the sequence of the sense strand with the exception of switching uracil for thymine. This directionality is because RNA polymerase can only add nucleotides to the 3' end of the growing mRNA chain. This use of only the 3' 5' DNA strand eliminates the need for the Okazaki fragments that are seen in DNA replication. This removes the need for an RNA primer to initiate RNA synthesis, as is the case in DNA replication.
The non-template sense strand of DNA is called the coding strand, because its sequence is the same as the newly created RNA transcript except for the substitution of uracil for thymine. This is the strand that is used by convention when presenting a DNA sequence.