In conversion of DNA to RNA, enzyme required are: (PGI June 2008)
**Question:** In the process of DNA to RNA conversion, which enzymes are required?
**Core Concept:** Transcription is the process by which the genetic information stored in DNA is transcribed into RNA. DNA polymerase, RNA polymerase, and DNA helicase are essential enzymes involved in transcription.
**Why the Correct Answer is Right:**
Correct Answer: **D. DNA Helicase**
DNA helicase is a crucial enzyme involved in transcription as it plays a critical role in unwinding the DNA double helix, separating the two strands before transcription begins. This allows the RNA polymerase to bind to the DNA template strand and synthesize RNA from the coding strand.
**Why Each Wrong Option is Incorrect:**
A. **Option A: RNA polymerase**: While RNA polymerase is indeed involved in transcription by synthesizing RNA from the coding strand, it is not the only enzyme required. DNA helicase is necessary to separate the DNA strands before transcription, which allows RNA polymerase to function effectively.
B. **Option B: DNA polymerase**: DNA polymerase plays a role in DNA replication, not transcription. Its primary function is to synthesize DNA by adding nucleotides to the growing DNA chain, not involved in transcription process.
C. **Option C: RNA polymerase**: While RNA polymerase is indeed involved in transcription, it is incorrect to state that it is the only enzyme required. DNA helicase is necessary for unwinding the DNA double helix, enabling RNA polymerase to synthesize RNA efficiently.
**Clinical Pearl:**
Understanding the essential role of enzymes like DNA helicase, RNA polymerase, and DNA polymerase in transcription is crucial for understanding molecular biology processes and their implications in various genetic disorders and treatments.
**Correct Answer:** D. DNA helicase
DNA helicase is a crucial enzyme in transcription as it aids in the unwinding of the DNA double helix, allowing RNA polymerase to bind and synthesize RNA from the coding strand. Without DNA helicase, transcription would be hindered, leading to altered gene expression and potential cellular dysfunction.