key term - Transcription elongation

Definition

Transcription elongation is the process during gene expression where RNA polymerase synthesizes a complementary RNA strand from a DNA template, extending the growing RNA molecule. This stage follows the initiation phase and is crucial for producing a full-length RNA transcript that will ultimately be translated into proteins. The regulation of transcription elongation is vital as it can influence gene expression levels and the efficiency of protein synthesis.

5 Must Know Facts For Your Next Test

1. Transcription elongation involves the addition of ribonucleotides to the growing RNA strand, which occurs in the 5' to 3' direction.
2. During elongation, RNA polymerase unwinds the DNA double helix, allowing access to the template strand while re-forming the double helix behind it.
3. The speed of transcription elongation can be influenced by various factors, including DNA sequence elements and the presence of transcription factors.
4. Transcription elongation can also be regulated through pausing or termination signals, which can affect overall gene expression.
5. Elongation factors assist RNA polymerase by enhancing its processivity and overcoming obstacles such as DNA-binding proteins on the template strand.

Review Questions

• How does transcription elongation contribute to gene expression, and what role does RNA polymerase play in this process?
  • Transcription elongation is essential for gene expression as it determines the length and completeness of the RNA transcript. RNA polymerase facilitates this process by synthesizing RNA from a DNA template, ensuring that ribonucleotides are added in sequence according to the template. By successfully elongating the RNA chain, it ultimately leads to a full transcript that can be translated into functional proteins.
• Discuss how transcription factors can impact transcription elongation and gene expression levels.
  • Transcription factors play a crucial role in regulating transcription elongation by assisting RNA polymerase in binding to promoters and influencing its activity during elongation. These proteins can enhance or inhibit the efficiency of RNA polymerase as it synthesizes RNA, thereby affecting how quickly or slowly transcripts are produced. Their ability to modulate elongation can lead to significant variations in gene expression levels, impacting cellular functions.
• Evaluate the significance of transcription elongation regulation in cellular processes and potential implications for diseases.
  • The regulation of transcription elongation is critical for maintaining proper gene expression patterns necessary for normal cellular functions. Dysregulation can lead to overexpression or underexpression of genes, contributing to various diseases, including cancer and genetic disorders. Understanding how transcription elongation is controlled offers insights into potential therapeutic targets for interventions aimed at correcting abnormal gene expression associated with these diseases.

Related terms

RNA polymerase:

An enzyme responsible for synthesizing RNA from a DNA template during the transcription process.

promoter: A specific DNA sequence that signals the start site for transcription and where RNA polymerase binds to initiate the process.

transcription factors:

Proteins that help regulate the transcription process by assisting in the binding of RNA polymerase to the promoter and influencing the elongation phase.