In which directions does a ribosome read the mRNA and build the polypeptide?

1. Every ribosome on a given transcript moves the same way along it. 2. The message is read from 5' to 3', which is also the direction in which it was transcribed. 3. The polypeptide grows from the N terminus toward the C terminus. 4. Each new amino acid is joined by its amino group to the carboxyl group of the chain already built, which is what fixes that polarity. 5. Reversing the mRNA direction would make transcription and translation incompatible in a bacterium, where both run at once. 6. Reversing the protein direction contradicts the way the peptide bond is formed at the A and P sites. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 15 "Genes and Proteins", section 15.5 Ribosomes and Protein Synthesis_