Keratins are a family of tough and insoluble proteins that are able to form fibers. They form the hard but unmineralized (not bony) structures in amphibians, mammals and reptiles/birds. Keratin, a byproduct from the poultry industry, has recently sparked interest. Keratins are made from a high proportion of the amino acid glycine (R=H) , followed by the amino acid alanine (R=-CH₃) . Two neighboring strands of keratin are shown below.
To what class of polymers is Keratin quite similar?

Question

Quizplus · Accepted Answer

Keratin is quite similar to polyamides, such as nylon. This is because both keratin and nylon are long, chain-like polymers composed of repeating units joined together by amide linkages. Both have a high proportion of amino acids as their repeating units, with glycine and alanine being the most common amino acids in keratin. Nylon and keratin also share similar physical properties, such as toughness and insolubility, due to their ability to form strong, fibrous structures.

Keratins Are a Family of Tough and Insoluble Proteins That