What substances do the shells of crayfish (crabs) and vertebrate bones consist of?

The shells of crayfish and crabs are composed of chitin, but like all aquatic crustaceans, it is also impregnated with lime. The bones of vertebrates are mainly composed of calcium phosphate salts, but the presence of organic substances – proteins is also necessary.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.