**Core Concept**
Aminoacyl t-RNA is a crucial molecule in protein synthesis, responsible for translating the genetic code into a specific amino acid sequence. It consists of transfer RNA (t-RNA) molecules that are covalently linked to their corresponding amino acids via an ester bond, facilitated by the enzyme aminoacyl-tRNA synthetase.

**Why the Correct Answer is Right**
Aminoacyl t-RNA plays a pivotal role in the initiation of protein synthesis by bringing the correct amino acid to the ribosome. This process involves the recognition of codons on the mRNA by specific t-RNA molecules, which then bind to the corresponding amino acids. The aminoacyl-tRNA synthetase enzyme catalyzes the attachment of the amino acid to the t-RNA, ensuring that the correct amino acid is incorporated into the growing protein chain. Without aminoacyl t-RNA, protein synthesis would be severely impaired.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because aminoacyl t-RNA is essential for the recognition of codons on the mRNA and the subsequent incorporation of amino acids into the protein chain.
**Option B:** This option is incorrect because aminoacyl t-RNA is necessary for the initiation of protein synthesis, not just its termination.
**Option C:** This option is incorrect because aminoacyl t-RNA is directly involved in the translation process, not just in the transcription of genetic information.

**Clinical Pearl / High-Yield Fact**
Aminoacyl t-RNA synthetase errors can lead to the incorporation of incorrect amino acids into proteins, resulting in frameshift mutations and potentially severe genetic disorders.

**Correct Answer:** D