Milady Cosmetology Practice Exam

Chains formed by peptide bonds linked together are known as:

1. Hydrogen Bonds

2. Disulfide Bonds

3. Polypeptide Bonds

4. Protein Chains

The correct answer is: Polypeptide Bonds

Chains formed by peptide bonds linked together are known as polypeptide bonds. This terminology is used because a peptide bond itself is the specific bond that forms between the amino group of one amino acid and the carboxyl group of another, creating a chain. When multiple amino acids are linked together through these peptide bonds, they form a polypeptide, which can further fold and form a functional protein. Polypeptides can consist of just a few amino acids or extend to several thousand, resulting in varying levels of complexity and function. The term "protein chains" sometimes refers to polypeptides as well, but it doesn't specifically indicate the type of bond that links the amino acids. Other bonds such as hydrogen and disulfide bonds are important for the structure and stability of proteins, but they do not form from the linkage of amino acids; instead, they influence the three-dimensional shape of the polypeptide once it is formed. Thus, the emphasis on peptide bonds defining polypeptide chains reinforces the understanding of how these structures are built from amino acids.