Question

Arrange the given events to correct sequence in relation to translation:
A. Adenylation of amino acid and aminoacyl-tRNA charging.
B. Formation of Peptide bond.
C. Recruitment of ribosome to the mRNA.
D. Correct positioning of charged tRNA into the P-site of the ribosome.
Choose the most appropriate answer from the options given below:

• A. A, B, C, D
• B. A, C, D, B
• C. B, A, D, C
• D. C, B, D, A

Hint:

Think of translation like building with LEGOs:

\textbf{A (Charging):} Get your specific LEGO bricks (amino acids) and attach them to the delivery trucks (tRNA).
\textbf{C (Recruitment):} Bring the workbench (ribosome) to the blueprint (mRNA).
\textbf{D (Positioning):} The first delivery truck (initiator tRNA) parks at the starting position (P-site).
\textbf{B (Peptide bond):} The next truck arrives, and you connect the LEGO bricks. \end{itemize}

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The question asks for the correct chronological sequence of major events during protein synthesis (translation).

Step 2: Detailed Explanation of the Sequence:
1. A. Adenylation of amino acid and aminoacyl-tRNA charging: This is a prerequisite for translation. The enzyme aminoacyl-tRNA synthetase must first "charge" each tRNA molecule with its corresponding amino acid. This happens continuously in the cytoplasm. It must occur before a tRNA can be used.
2. C. Recruitment of ribosome to the mRNA: This is the initiation of translation. The small ribosomal subunit binds to the mRNA molecule and scans for the start codon (AUG).
3. D. Correct positioning of charged tRNA into the P-site of the ribosome: Once the start codon is found, the initiator tRNA (carrying methionine), which has already been charged (Step A), binds to the P-site of the ribosome. This completes the initiation complex.
4. B. Formation of Peptide bond: This is the first step of the elongation cycle. A second charged tRNA enters the A-site, and the ribosome catalyzes the formation of a peptide bond between the amino acid in the P-site (methionine) and the new amino acid in the A-site. This cycle of tRNA entry, peptide bond formation, and translocation repeats.

Step 3: Final Answer:
The logical sequence of events is A \(\rightarrow\) C \(\rightarrow\) D \(\rightarrow\) B. This corresponds to option (B).