Eukaryotic Transcription Enzyme Identification
Eukaryotic transcription is the fundamental process where genetic information encoded in DNA is copied into messenger RNA (mRNA). This process is catalyzed by specific enzymes.
Core Enzyme for Transcription
- The primary enzyme responsible for synthesizing RNA from a DNA template is called DNA-dependent RNA polymerase.
- This enzyme reads the DNA sequence and builds a complementary RNA strand.
- In eukaryotes, transcription is specifically carried out by DNA-dependent RNA polymerase.
Analysis of Options
- Option 1: DNA-dependent RNA polymerase - Correct. This enzyme synthesizes RNA using a DNA template, which is the definition of transcription.
- Option 2: DNA-dependent DNA polymerase - Incorrect. This enzyme synthesizes DNA using a DNA template, which is involved in DNA replication, not transcription.
- Option 3: RNA-dependent DNA polymerase - Incorrect. This enzyme synthesizes DNA using an RNA template (reverse transcriptase), involved in processes like retroviral replication.
- Option 4: RNA-dependent RNA polymerase - Incorrect. This enzyme synthesizes RNA using an RNA template, involved in RNA virus replication.
Therefore, the correct enzyme for eukaryotic transcription is DNA-dependent RNA polymerase.
Important Questions from Replication Transcription Splicing and Translation
Messenger RNAs (mRNAs) translate to generate polypeptides and the translation terminates at the UGA, UAG or UAA stop codons. The AGA codon acts as additional stop codon in the mitochondria. The longest possible polypeptide(s) that can be hypothetically translated in the cytosol and/or mitochondria, from the given full length mRNA sequence (36 nucleotides) is/are
5'-AACACCAUGACCCAUGUGGCGAGACGGUAGUUAAAA- 3'
- Which of the following statements about initiation of DNA replication in eukaryotes is/are true?
Match the drugs in Group I with their mechanism of action in Group II.
Group I Group II P) Paclitaxel 1) Inhibits protein translation Q) Colchicine 2) Inhibits microtubule depolymerization R) Etoposide 3) Inhibits DNA replication S) Methotrexate 4) Alkylates DNA 5) Inhibits dihydrofolate reductase 6) Inhibits microtubule polymerization Match the enzyme (Column I) with its corresponding function (Column II).
Column I Column II P. Primase 1. RNA dependent RNA synthesis Q. Reverse transcriptase 2. DNA dependent DNA synthesis R. RNA Replicase 3. RNA dependent DNA synthesis S. DNA Polymerase III 4. DNA dependent RNA synthesis Which of the following statements regarding the below mentioned mRNA sequence is/are TRUE?
5`-UGAUGAGCCUUAACCGGGAACGAAUUUAAG-3`
