Where does transcription occur and where does translation occur in the cell?
The correct Answer and Explanation is:
Transcription occurs in the nucleus of the cell, where the DNA is located. Translation occurs in the cytoplasm, specifically on the ribosomes, which may be free-floating or attached to the endoplasmic reticulum.
Explanation
The processes of transcription and translation are fundamental to gene expression, ensuring that genetic information stored in DNA is converted into functional proteins.
Transcription is the first step of gene expression. It takes place in the nucleus, where the DNA, which carries genetic instructions, is used as a template to synthesize messenger RNA (mRNA). This is done by RNA polymerase, an enzyme that unwinds the DNA helix and assembles a complementary RNA strand based on the DNA sequence. The resulting mRNA carries the genetic code necessary for building a protein. Before leaving the nucleus, the mRNA undergoes modifications such as splicing, where introns (non-coding regions) are removed, and the addition of a 5′ cap and poly-A tail to protect and facilitate translation.
Once the mRNA is fully processed, it exits the nucleus through nuclear pores and enters the cytoplasm, where translation occurs. Translation is the process by which ribosomes read the mRNA sequence and assemble the corresponding protein. This process involves transfer RNA (tRNA), which carries specific amino acids to the ribosome. The ribosome moves along the mRNA strand, reading triplet codons, and matching them with the appropriate tRNA carrying the correct amino acid. This process continues until a stop codon is reached, signaling the completion of protein synthesis.
Ultimately, transcription and translation ensure that genetic instructions encoded in DNA are properly expressed as proteins, which perform vital functions in the cell. Let me know if you need further clarification!
