PSI Barbering Practice Exam

What component provides strength, elasticity, and natural color to the hair?

1. Amino acids

2. Melanin pigment

3. Keratinized protein

4. Salt bonds

The correct answer is: Amino acids

The component that provides strength, elasticity, and natural color to the hair is keratinized protein. Hair is primarily composed of a fibrous protein called keratin, which is essential for its structure and resilience. Keratin contributes significantly to the tensile strength of hair, allowing it to withstand varying environmental conditions and mechanical stress without breaking. While amino acids are the building blocks of proteins, including keratin, they do not directly provide the properties associated with the strength and elasticity of hair in the same immediate way that keratin does. Melanin pigment is responsible for the color of hair but does not contribute to strength or elasticity. Salt bonds, which are weaker bonds formed between certain amino acids in the hair structure, contribute to the overall integrity of the hair but are not the primary source of its strength or elasticity. Thus, keratinized protein is the correct answer as it directly encompasses the essential characteristics that maintain the hair's functional and aesthetic qualities.