Redseal Hairstyling License Practice Test

What are the chemical bonds that join amino acids together called?

1. Hydrogen bonds

2. Peptide bonds

3. Disulfide bonds

4. Ionic bonds

The correct answer is: Peptide bonds

The chemical bonds that join amino acids together are known as peptide bonds. These bonds are formed through a process called dehydration synthesis or condensation reaction, where the amino group of one amino acid reacts with the carboxyl group of another, releasing a molecule of water and creating a covalent bond that links the two amino acids. This bond is crucial for the formation of proteins, as proteins are essentially long chains (polymers) of amino acids linked by these peptide bonds. Peptide bonds give proteins their unique structure and function, as the sequence and arrangement of the amino acids will dictate the final three-dimensional shape of the protein and its functionality within biological systems. In contrast, hydrogen bonds generally occur between polar molecules and often play a role in stabilizing the structures of proteins and nucleic acids, but they do not link amino acids together. Disulfide bonds are specific types of covalent bonds that form between the sulfur atoms of cysteine residues within a protein, providing stability to protein structures, but they are not responsible for linking the amino acids in the primary sequence. Ionic bonds involve the attraction between oppositely charged ions and also do not contribute to the formation of the primary structure of proteins. Thus, peptide bonds are specifically the key connections that