Eukaryotic cells, transcription cannot begin until certain DNA nucleases have isolated the transcription unit. 50v852 transcription factors have found the promoter caps removed from the mRNA. The two DNA strands have completely separated and exposed the template. The DNA introns are removed from the template.
The Correct Answer and Explanation is:
In eukaryotic cells, transcription is a complex process that involves several key steps before the actual synthesis of RNA can begin. Here’s a breakdown of how it works:
- Transcription Factors: Transcription cannot begin until specific proteins, called transcription factors, bind to the DNA. These transcription factors recognize and bind to the promoter region of a gene. The promoter is a sequence of DNA that signals the start of a transcription unit. Once these transcription factors bind to the promoter, they help recruit RNA polymerase, the enzyme responsible for synthesizing the RNA transcript.
- Unwinding of DNA: Before transcription can take place, the DNA strands must be separated, or “unwound.” This is carried out by helicase enzymes, which break the hydrogen bonds between complementary bases of the two DNA strands. The process exposes the template strand of the DNA, which serves as the guide for RNA synthesis.
- Initiation of Transcription: With the template strand exposed, RNA polymerase begins synthesizing an RNA strand by adding complementary RNA nucleotides to the growing chain. This process occurs in the 5′ to 3′ direction, meaning the RNA strand is built in the opposite direction of the template strand.
- Capping and Introns Removal: In eukaryotic cells, mRNA processing takes place after transcription has begun. One of the first modifications is the addition of a 5′ cap to the mRNA. This cap helps stabilize the mRNA and assists in its transport out of the nucleus. In addition, the introns, which are non-coding sequences within the gene, are removed through a process called splicing. The remaining exons, which are the coding regions, are joined together to form the mature mRNA.
These steps ensure that the mRNA is properly processed and ready to be translated into a protein at the ribosome. The entire transcription process, from initiation to processing, is crucial for the accurate expression of genetic information in eukaryotic cells
