Template strand

Definition

The template strand is the single strand of DNA that serves as a guide for synthesizing RNA during the process of transcription. This strand is read in the 3' to 5' direction, allowing the RNA polymerase enzyme to create a complementary RNA strand in the 5' to 3' direction. The fidelity of gene expression relies on the accurate pairing of nucleotides on the template strand, ensuring that the resulting RNA carries the correct genetic information.

5 Must Know Facts For Your Next Test

1. The template strand is essential for producing mRNA, which carries genetic instructions from DNA to ribosomes for protein synthesis.
2. Transcription begins at specific promoter regions on the template strand, where RNA polymerase binds to initiate the process.
3. The sequence of nucleotides on the template strand dictates the sequence of nucleotides in the resulting RNA molecule through complementary base pairing.
4. During transcription, only one of the two DNA strands serves as a template, meaning genes can be transcribed in different directions on different strands.
5. Mistakes made during transcription can lead to mutations in mRNA, potentially resulting in incorrect protein production or loss of function.

Review Questions

• How does the template strand ensure accurate RNA synthesis during transcription?
  • The template strand ensures accurate RNA synthesis by providing a specific sequence of nucleotides that RNA polymerase reads in a 3' to 5' direction. As it moves along this strand, RNA polymerase adds complementary RNA nucleotides in a 5' to 3' direction. This complementary base pairing between adenine and uracil (and cytosine and guanine) is crucial for maintaining the integrity of genetic information being transferred from DNA to RNA.
• Discuss the relationship between the template strand and coding strand during transcription.
  • The relationship between the template strand and coding strand is integral to transcription. While the template strand is used by RNA polymerase to synthesize mRNA, the coding strand has the same nucleotide sequence as the resulting mRNA (with thymine replaced by uracil). This means that while only one strand serves as a template, both strands contain vital information about gene expression, with each playing a distinct role in the transcription process.
• Evaluate how errors in reading the template strand can impact gene expression and cellular function.
  • Errors in reading the template strand can lead to incorrect mRNA sequences, which may result in faulty proteins being produced. If these proteins are crucial for specific cellular functions, their malfunction can disrupt metabolic pathways, signaling processes, or structural integrity within cells. This cascading effect can lead to diseases, impaired cellular processes, or even developmental issues, highlighting the importance of fidelity in reading the template strand during transcription.

Related terms

RNA polymerase:

An enzyme that synthesizes RNA from a DNA template during transcription by unwinding the DNA and adding complementary RNA nucleotides.

coding strand:

The DNA strand that has the same sequence as the synthesized RNA (except for thymine being replaced by uracil) and is not used as a template during transcription.

transcription factors:

Proteins that help regulate the process of transcription by assisting RNA polymerase in binding to the template strand and initiating RNA synthesis.