Final answer:
The 5' and 3' ends of an mRNA molecule indicate the start and end of protein synthesis, with the former usually capped and the latter typically featuring a poly(A) tail. Polypeptide amino acid molecules have an N-terminal and a C-terminal, which are important for the protein's function. Translation involves reading mRNA's codons to synthesize proteins until a stop codon signals the end.
Step-by-step explanation:
The ends of each mRNA molecule indicate the starting and stopping points for protein synthesis. The 5' end of mRNA often begins with a cap that is crucial for translation initiation, while the 3' end typically has a poly(A) tail which protects the mRNA from degradation and assists in the export from the nucleus. In polypeptide amino acid molecules, the ends are referred to as the N-terminal and C-terminal. The N-terminal is the end of the protein or polypeptide where the amino group is free, and the C-terminal is the end of the protein where the carboxyl group is free. These ends are important during protein synthesis and later for the protein's functioning and localization. During translation, the mRNA's codons are read in sets of three bases, each of which encodes for a single amino acid, adding to the growing polypeptide chain until a stop codon is reached, which signals the completion of the protein synthesis.