Final answer:
The first stage of protein synthesis is transcription, where the DNA code is transcribed into mRNA inside the cell nucleus. This mRNA then serves as the template for the translation process at the ribosome.
Step-by-step explanation:
The First Stage of Protein Synthesis: Transcription
The first stage of protein synthesis is transcription. This critical process entails the unfolding of DNA within the cell nucleus, enabling the synthesis of a messenger RNA (mRNA) strand. Transcription is the crucial first step in the pathway that leads to the production of proteins, foundational components of all living organisms. It is during transcription that the information coded in DNA is rewritten into mRNA, which then travels out of the nucleus and into the cytoplasm where the second stage of protein synthesis, known as translation, occurs.
In translation, the synthesized mRNA interacts with transfer RNA (tRNA) at the ribosome to code for the sequence of amino acids that will form a growing polypeptide chain. With the assistance of various enzymes and the expenditure of energy, the tRNA molecules bring specific amino acids to the mRNA according to the codon sequences, thus elongating the polypeptide chain. The entire process of translation includes three phases: initiation, in which the ribosome binds to the mRNA; elongation, where tRNAs add amino acids to the growing chain; and termination, which occurs when a stop codon is reached and the completed protein is released.
The flow of information from DNA to RNA to protein is a central dogma of molecular biology, and the efficiency of this process is vital for the correct functioning of cells and the organism as a whole. Understanding the mechanisms of protein synthesis is therefore fundamental for the study of all biological systems.