University of Toronto (UofT) BIO230H1 From Genes to Organisms Midterm Practice Exam

The ribosome is the cellular component responsible for translating the first 10 codons from tmRNA. tmRNA, or transfer-messenger RNA, is involved in the rescue of stalled ribosomes on mRNA and plays a role in managing defective mRNAs. During translation, the ribosome functions as the site where the information encoded in the mRNA is read and translated into a polypeptide chain, making it critical for the process of protein synthesis.

The ribosome's ability to read the codons of tmRNA is essential for delivering the corresponding amino acids, enabling the synthesis of proteins. The ribosome facilitates the formation of peptide bonds between amino acids, following the sequence dictated by the codons. This interaction ensures that the translation process is accurate and efficient.

In contrast, the endoplasmic reticulum is primarily involved in the synthesis and folding of proteins but does not perform the translation of codons. The nucleus is the cellular organelle where DNA is transcribed into mRNA, but it does not play a direct role in the translation process. Mitochondria are involved in energy production and have their own genetic material, but they are not directly involved in the translation of tmRNA codons as performed by the ribosome. Thus,