Final answer:
Transcription is the process by which RNA is synthesized from a DNA template within the cell's nucleus, involving the enzyme RNA polymerase. It results in the creation of mRNA, which exits the nucleus and guides protein synthesis in the cytoplasm.
Step-by-step explanation:
Transcription is the biological process by which the information in a gene's DNA is encoded into messenger RNA (mRNA). This process begins within the nucleus of the cell when the relevant section of DNA unwinds, creating a transcription bubble. An enzyme called RNA polymerase then facilitates the synthesis of an RNA strand from the DNA template. This RNA strand is complementary to the DNA sequence and follows base pairing rules, with one key difference: in RNA, uracil (U) pairs with adenine (A), rather than thymine as in DNA.
Once the RNA is synthesized, it is known as pre-mRNA and requires further processing. Once processed, the mature mRNA leaves the nucleus and enters the cytoplasm, where it serves as a template for protein synthesis during the process of translation. Besides mRNA, two other forms of RNA are synthesized through transcription - transfer RNA (tRNA) and ribosomal RNA (rRNA), both are crucial for the protein synthesis process. The tRNA transports amino acids to the ribosome, the site of protein synthesis, while rRNA becomes a part of the ribosome itself.
Errors during transcription can lead to mutations which can result in hereditary or age-related diseases. It is a critical step in the central dogma of molecular biology, which describes the flow of genetic information within a biological system.