Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

What happens at the ribosome during protein synthesis?

1. DNA is transcribed into RNA

2. Proteins are synthesized from mRNA

3. Amino acids are stored for future use

4. Cellular waste is processed

The correct answer is: Proteins are synthesized from mRNA

During protein synthesis, the ribosome plays a crucial role in translating the information encoded in messenger RNA (mRNA) into a specific sequence of amino acids, ultimately forming a protein. Once mRNA is synthesized during transcription (which occurs in the nucleus), it is transported to the ribosomes, which can be found either freely suspended in the cytoplasm or attached to the endoplasmic reticulum. At the ribosome, the mRNA strand is read in sets of three nucleotides, known as codons. Each codon corresponds to a specific amino acid or a stop signal during the translation process. Transfer RNA (tRNA) molecules bring the appropriate amino acids to the ribosome as it decodes the mRNA sequence. As the ribosome moves along the mRNA, it facilitates the bonding of adjacent amino acids, creating a polypeptide chain that will fold into a functional protein. The other options refer to different biological processes. DNA transcription into RNA occurs in the nucleus, while the storage of amino acids and the processing of cellular waste are distinct functions not associated with the active role of the ribosome in translating mRNA into a polypeptide. The ribosome's primary function is indeed the synthesis of proteins, making option B the accurate