Final answer:
mRNA is synthesized during transcription, which takes place in the nucleus of eukaryotic cells where the DNA resides. mRNA must be processed before being exported to the cytoplasm, where it undergoes translation at the ribosomes to synthesize proteins.
Step-by-step explanation:
Understanding mRNA Synthesis and Its Importance
The process by which mRNA (messenger RNA) is synthesized is known as transcription. This crucial process occurs in the nucleus of eukaryotic cells. During transcription, an enzyme called RNA polymerase reads the DNA sequence and creates a complementary mRNA strand. The newly formed mRNA strand contains the codons necessary for protein synthesis. It is imperative for transcription to occur in the nucleus because that is where the cell's DNA is housed, and mRNA acts as a messenger that carries genetic information from DNA to the cytoplasm for protein synthesis.
After mRNA is produced, it undergoes several processing steps before being considered a mature mRNA capable of directing protein synthesis. These steps include the addition of a 5' cap, poly-A tail, and the splicing of introns and exons to create a continuous coding sequence. The presence of the 5' cap and poly-A tail is especially crucial as they protect the mRNA from degradation and assist in its export from the nucleus.
Once the mature mRNA reaches the cytoplasm, it undergoes translation, a process that takes place in the ribosomes. Translation is the synthesis of proteins directed by the sequence of codons on the mRNA. The tRNA molecules, each bearing anticodons, bring the appropriate amino acids to the ribosome, where they are assembled into a polypeptide chain according to the sequence dictated by the mRNA. Upon completion, the polypeptide chain may undergo further modifications to become a functional protein.