How are amino acids connected covalently in proteins?

How are amino acids connected covalently in proteins?

• A. Hydrogen bonds stabilize polypeptide chains
• B. Two amino acids are covalently bound by a peptide bond.
• C. Peptide bonds link nucleotides in DNA
• D. Peptide bonds connect lipids

Answer: (B)

Amino acids in proteins are connected covalently by peptide bonds, which form when the carboxyl group of one amino acid reacts with the amino group of the next, releasing a molecule of water. This creates a covalent linkage that builds the polypeptide backbone, running from the N terminus to the C terminus. The peptide bond is strong and has partial double-bond character, making it planar and relatively rigid, which helps define the overall shape of the protein. After this chain is formed, folding is guided by noncovalent interactions like hydrogen bonds, ionic interactions, and hydrophobic effects, but those bonds do not join amino acids covalently. The other descriptions describe interactions or bonds in places other than linking amino acids in proteins, such as DNA phosphodiester bonds or lipid connections, which aren’t the covalent links between amino acids in proteins.

Amino acids in proteins are connected covalently by peptide bonds, which form when the carboxyl group of one amino acid reacts with the amino group of the next, releasing a molecule of water. This creates a covalent linkage that builds the polypeptide backbone, running from the N terminus to the C terminus. The peptide bond is strong and has partial double-bond character, making it planar and relatively rigid, which helps define the overall shape of the protein. After this chain is formed, folding is guided by noncovalent interactions like hydrogen bonds, ionic interactions, and hydrophobic effects, but those bonds do not join amino acids covalently. The other descriptions describe interactions or bonds in places other than linking amino acids in proteins, such as DNA phosphodiester bonds or lipid connections, which aren’t the covalent links between amino acids in proteins.