Final answer:
The fourth step in the process of translation is the elongation phase, where tRNAs bring amino acids to the ribosome and peptide bonds are formed to extend the growing polypeptide chain.
Step-by-step explanation:
The process of translation in biology refers to the synthesis of proteins by using the information encoded in messenger RNA (mRNA). It involves several key steps, with the fourth step focusing on the elongation phase of protein synthesis. To recap, the first step is the activation of amino acids. The second step involves the mRNA traveling to the ribosome from the nucleus. The third step is where initiation takes place, involving the binding of a ribosome to the mRNA transcript and the formation of an initiation complex.
In the fourth step, the elongation stage of translation, the ribosome continues to read the mRNA sequence. A transfer RNA (tRNA) molecule with a complementary anticodon binds to the current codon on the mRNA strand presenting its amino acid cargo. The polypeptide chain then attaches to this new amino acid through peptide bond formation, which is catalyzed by enzymes and requires energy. This complex process is repeated as the ribosome moves along the mRNA, one codon at a time, and continues to add amino acids to the growing polypeptide chain.