Question: Which of the following is/are true for secondary protein structures, protein domains, linkers, hinges, and/or protein modification? Need Assignment Help? (Select all that apply): Group of answer choices Post-translational modification is when the amino acid(s) are modified after they have exited the ribosome during protein synthesis. Alpha-helices occur when the side chains, amide, and carbonyl groups of the primary sequence project alternately on either side of the chain. In a Beta-sheets, or beta-strands, the polypeptide chain spirals in a right-handed helix and hydrogen bonding between the carbonyl group of one amino acid and the amino group of the fifth amino acid residue holds them together. When secondary structures stop there is typically a highly structured space before the next secondary structure forms termed a connector. A domain is the goldilocks region between being too short and too long, which is between five and seventy-five residues.