Final answer:
The steps from gene to protein include transcription in the nucleus, mRNA processing, translation in the cytoplasm, where the mRNA is decoded into a protein, and DNA replication, which is not a part of protein synthesis but important for cell division.
Step-by-step explanation:
The journey from gene to protein is a complex process that involves a series of intricate steps. This can be visually represented as follows:
Transcription: Within the cell nucleus, a portion of DNA is used as a template to synthesize messenger RNA (mRNA) in a process called transcription. The DNA sequence is copied into a complementary mRNA sequence. This newly formed mRNA is then processed before it leaves the nucleus.
mRNA Processing: Once the initial mRNA is synthesized, it undergoes several modifications, including the addition of a 5' cap, a poly-A tail, and splicing where introns are removed, and exons are joined to form a continuous coding sequence.
Translation: The modified mRNA molecule travels out of the nucleus into the cytoplasm. Here, a ribosome reads the mRNA sequence and with the help of transfer RNA (tRNA) molecules, translates the genetic code into a polypeptide chain, which subsequently folds into a functional protein.
DNA Replication: This process occurs before cell division, ensuring that each new cell receives an exact copy of the DNA. It is not directly involved in protein synthesis, but is vital for cell proliferation and maintenance of genetic information.
A graphic representation of these steps would illustrate the flow of genetic information from the DNA in the nucleus to the site of protein synthesis in the cytoplasm, showing the cellular machinery involved at each stage.