Which statement correctly describes the bonds between amino acids in a protein and what determines the amino acid sequence?

Which statement correctly describes the bonds between amino acids in a protein and what determines the amino acid sequence?

• A. Hydrogen bonds between amino acids; the sequence is determined by the salt concentration
• B. Ionic bonds link amino acids; the sequence is determined by the cell cycle
• C. Peptide bonds link amino acids; the sequence is determined by the gene encoding the protein
• D. Disulfide bonds between amino acids; the sequence is determined by RNA editing

Answer: (C)

The main idea is how a protein's chain is built and what fixes the order of those amino acids. The bonds that connect one amino acid to the next in a protein are peptide bonds. A peptide bond forms when the carboxyl group of one amino acid reacts with the amino group of the next, creating a covalent link and a growing polypeptide backbone. The sequence of amino acids—that order in which they appear—is determined by the gene that encodes the protein. DNA in the gene is transcribed into mRNA, and the ribosome translates that mRNA using the genetic code to insert the corresponding amino acids in the specified order. So the idea is: peptide bonds join the chain, and the gene (via DNA transcription and mRNA translation) sets the exact sequence. Hydrogen bonds, ionic bonds, and disulfide bonds all play roles in the structure and stability of the folded protein, but they do not define the main-chain linkage or the sequence itself. The sequence isn’t determined by salt concentration, cell cycle, or RNA editing; it’s set by the genetic information in the gene.

The main idea is how a protein's chain is built and what fixes the order of those amino acids. The bonds that connect one amino acid to the next in a protein are peptide bonds. A peptide bond forms when the carboxyl group of one amino acid reacts with the amino group of the next, creating a covalent link and a growing polypeptide backbone. The sequence of amino acids—that order in which they appear—is determined by the gene that encodes the protein. DNA in the gene is transcribed into mRNA, and the ribosome translates that mRNA using the genetic code to insert the corresponding amino acids in the specified order. So the idea is: peptide bonds join the chain, and the gene (via DNA transcription and mRNA translation) sets the exact sequence.

Hydrogen bonds, ionic bonds, and disulfide bonds all play roles in the structure and stability of the folded protein, but they do not define the main-chain linkage or the sequence itself. The sequence isn’t determined by salt concentration, cell cycle, or RNA editing; it’s set by the genetic information in the gene.