Crab shells contain BOTH calcium and chitin.

The exoskeleton of American lobster is composed of chitin, proteins, calcium, carotenoids and traces of other minerals and organic compounds.

Basically, the carapace is the shell on back of the crab that is made of a hard bone called chitin[1]. Chitin is a polymer which is the main component of arthropod’s exoskeletons such as crabs [2].

Lightweight and flexible, yet strong: The properties of the lobster shell derive from a sophisticated structure of chitin and calcium carbonate.

Chitin is a structural component of arthropod exoskeletons, fungi cell walls, mollusk shells, and fish scales. While humans don’t produce chitin, it has uses in medicine and as a nutritional supplement. It may be used to make biodegradable plastic and surgical thread, as a food additive, and in paper manufacturing.

Chitin acts as an insoluble fiber, meaning it doesn’t dissolve in water. That’s why it doesn’t easily break down in our digestive tract.

Chitin is found in the shells of many animals including crustaceans, insects, and other arthropods, as well as the cell walls of fungi. Similar to cellulose, the linear polymer packs to form a tight crystalline microstructure, thereby providing structure and protection.

A tough, semitransparent substance that is the main component of the exoskeletons of arthropods, such as the shells of crustaceans and the outer coverings of insects. Chitin is also found in the cell walls of certain fungi and algae. Chemically, it is a nitrogenous polysaccharide (a carbohydrate).

Chitin is commercially produced from the shell waste of crabs, shrimps, and krills through a series of deproteinization and demineralization processes to remove the protein and minerals, which together with chitin form the composite structure of the shells.

Chitin is a homopolysaccharide. This just means that it is made up of repeating units of the same monosaccharide – in this case that monosaccharide is N-acetylglucosamine. Other examples of homopolysaccharides are glycogen and cellulose.

Homopolysaccharides (homoglycans) consist of a single type of monomer. Cellulose and starch are the best-known examples.

Cellulose is a macromolecule composed of β linked D-glucose monomeric units. Hence, cellulose is indeed a homopolymer. Chitin is a homopolysaccharide made of repeated units of N-acetylglucosamine, a derivative of glucose. Hence, chitin is not a heteropolymer.

For example, starch, glycogen, inulin, cellulose, chitin, etc. Agar, pectin, hyaluronic acid, heparin, etc., are heteropolysaccharides.

Hint: Homopolysaccharides are those polysaccharides that are composed of only one type of sugar monomer or monosaccharides. These monomers react with other monomers to form polymers. Starch, glucose, and glycogen are examples of typical homopolysaccharides. Starch is mostly produced by green plants to store energy.

Here Glucose, Maltose, and Fructose are carbohydrate. Glycine is not a carbohydrate.

Glycogen is a homopolysaccharide found in the liver and muscles of animals, where it is used to store energy. Chemically, glycogen is related to starch and closely resembles amylopectin. This is why the aggregates of starch are called granules and those of glycogen, spheres.

Heteropolysaccharide: These are made from quite one sort of monosaccharide. Examples include Pectin, Peptidoglycan, and Agar. – Glycogen is a polysaccharide of glucose linked by alpha- 1,4-glycosidic bonds. – Starch is a polysaccharide of glucose linked by alpha- 1,4-glycosidic linkage.