Florida Barber License Practice Test

Which bond can be easily reformed after being broken through heat?

1. Disulfide bond

2. Hydrogen bond

3. Salt bond

4. Peptide bond

The correct answer is: Hydrogen bond

The hydrogen bond is a type of weak chemical bond that forms when a hydrogen atom is attracted to a highly electronegative atom, such as oxygen or nitrogen. Because of the relatively weak nature of hydrogen bonds, they can be easily broken and reformed through changes in temperature or the presence of certain substances. In the context of heat, increasing temperature can disrupt hydrogen bonds, leading to changes in the structure of proteins, for example. However, when the temperature is lowered, or when the proper conditions are reintroduced, these bonds can reform relatively easily, allowing the structure to regain its original configuration. In contrast, other bonds such as disulfide and peptide bonds are much stronger. Disulfide bonds involve covalent links between sulfur atoms of cysteine residues in proteins and require more significant chemical changes or reducing agents for breakage and reformation. Peptide bonds, which link amino acids in proteins, are also covalent and do not reform simply through heat. Salt bonds, or ionic bonds, are also relatively strong and cannot be readily reformed through mere temperature changes.