Which process is part of translation but not transcription?
A DNA template is used to create an mRNA strand.
A tRNA template is used to create a DNA strand.
A tRNA template is used to create an mRNA strand.
An mRNA template is used to create an amino acid chain.
The Correct Answer and Explanation is:
The correct answer is: An mRNA template is used to create an amino acid chain.
Explanation:
To understand this, we need to differentiate between transcription and translation, two key processes in protein synthesis.
- Transcription:
- This is the process of synthesizing an RNA molecule from a DNA template.
- During transcription, the DNA sequence is transcribed into messenger RNA (mRNA) by the enzyme RNA polymerase.
- The mRNA serves as a copy of the genetic information contained in the DNA, which will later be used to make proteins during translation.
- This process occurs in the nucleus (in eukaryotic cells) and produces a complementary mRNA strand.
- Translation:
- This is the process in which the mRNA template is used to synthesize an amino acid chain (a protein) at the ribosome.
- The mRNA produced during transcription is transported to the ribosome in the cytoplasm, where translation occurs.
- Here, the mRNA’s codons (three-nucleotide sequences) are read by transfer RNA (tRNA) molecules, each carrying a specific amino acid.
- The ribosome facilitates the binding of the tRNA anticodons to the mRNA codons, adding the corresponding amino acids to a growing polypeptide chain.
- This results in the formation of a protein.
Now, let’s analyze the options:
- Option 1 (A DNA template is used to create an mRNA strand): This is transcription, where the DNA template is used to create mRNA. This is not the correct answer.
- Option 2 (A tRNA template is used to create a DNA strand): This is not a valid process in either transcription or translation, and it doesn’t occur in protein synthesis.
- Option 3 (A tRNA template is used to create an mRNA strand): This is incorrect because tRNA does not serve as a template for mRNA production. mRNA is synthesized from DNA, not tRNA.
- Option 4 (An mRNA template is used to create an amino acid chain): This is translation, where mRNA directs the synthesis of a protein by guiding tRNA molecules to add amino acids to the polypeptide chain. This is the process specific to translation and is not part of transcription.
Thus, Option 4 accurately describes the process of translation, which is the correct answer.