PSI Barbering Practice Exam

A weak, physical bond influenced by changes in temperature or pH is known as?

1. Salt bond

2. Hydrogen bond

3. Disulfide bond

4. Covalent bond

The correct answer is: Salt bond

The correct choice refers to a type of bond that is relatively weak and can be altered by changes in environmental conditions, such as temperature or pH. Salt bonds are a type of ionic bond that form between positively and negatively charged groups within the protein structure. These bonds are essential for maintaining the shape and structure of hair, skin, and nails but can be disrupted by changes in temperature or pH, leading to changes in the hair's texture or behavior. In contrast, hydrogen bonds, while also considered weak, primarily involve the attraction between hydrogen atoms bonded to electronegative atoms and other electronegative atoms. They are significant in maintaining molecular structure but are less influenced by pH changes compared to salt bonds. Disulfide bonds are much stronger covalent bonds formed between cysteine amino acids and are not easily disrupted by temperature or pH changes; instead, they require more intense conditions (such as strong chemicals) to break. Covalent bonds are the strongest type of chemical bond formed by the sharing of electrons between atoms and are typically very stable, thus not subject to easy disruption by environmental factors like temperature or pH. Understanding these distinctions highlights why the weak, physical bond affected by temperature or pH is accurately termed a salt bond.