Transcription

Overview

Transcription is the process by which genetic information encoded in DNA is copied into messenger RNA (mRNA) by the enzyme RNA polymerase. This process begins when RNA polymerase binds to a specific region of the DNA called the promoter, which signals the start of a gene. The enzyme then unwinds the DNA strands and synthesizes a complementary RNA strand by adding ribonucleotides in the 5' to 3' direction, following the base-pairing rules. Once the RNA strand is synthesized, it detaches from the DNA, and the DNA strands re-anneal. The resulting mRNA molecule then undergoes processing before being translated into a protein

Questions and Answers

1. What is transcription?

   Transcription is the process by which genetic information encoded in DNA is copied into messenger RNA (mRNA) by the enzyme RNA polymerase

2. What enzyme is primarily responsible for transcription?

   RNA polymerase is the enzyme responsible for synthesizing RNA from the DNA template during transcription

3. What is the role of the promoter in transcription?

   The promoter is a specific DNA sequence where RNA polymerase binds to initiate transcription, signaling the start of a gene

4. How does RNA polymerase know where to start transcription?

   RNA polymerase recognizes specific sequences in the promoter region, such as the -10 and -35 sequences in prokaryotes, which guide the initiation of transcription

5. What is the template strand in transcription?

   The template strand, also known as the antisense strand, is the DNA strand that is used by RNA polymerase to synthesize the complementary RNA strand

Multiple-Choice Questions

1. What is the primary function of RNA polymerase in transcription?

   a) To unwind the DNA
   b) To synthesize RNA from a DNA template
   c) To translate mRNA into protein
   d) To repair DNA
   Answer: b) To synthesize RNA from a DNA template

2. Where does transcription occur in eukaryotic cells?

   a) Cytoplasm
   b) Nucleus
   c) Ribosome
   d) Mitochondria
   Answer: b) Nucleus

3. What is the role of the promoter in transcription?

   a) It terminates transcription
   b) It is the site where RNA polymerase binds to initiate transcription
   c) It codes for proteins
   d) It stabilizes the mRNA
   Answer: b) It is the site where RNA polymerase binds to initiate transcription

4. Which strand of DNA is used as the template during transcription?

   a) Coding strand
   b) Non-coding strand
   c) Sense strand
   d) Antisense strand
   Answer: d) Antisense strand

5. In which direction is RNA synthesized during transcription?

   a) 3' to 5'
   b) 5' to 3'
   c) 5' to 5'
   d) 3' to 3'
   Answer: b) 5' to 3'