ENT207 Lecture Notes - Lecture 2: Calcite, Aragonite, Invertebrate

• School: University of Alberta
• Department: Entomology (Biological Sciences)
• Course: ENT207
• Professor: Maya Evenden

Document Summary

Anthropod: an invertebrate animal having an exoskeleton, a segmented body and jointed appendages. All anthropods are the descendants of a single common ancestor. Jellyfishes and mice do not: hard exoskeleton; armor made of chitin, produced by the skin and then hardens into a. Integuments: the cell membrane and any coating it secretes. Chitin is a heavy polysaccharide containing amino groups and is made in the epidermis. Sclerotization: involves the molecular stabilization of the protein chains of the cuticles by establishment of cross-links. Sclerotin, the product of this process is a kind of natural plastic. Sclerotization or tanning involves dehydration (crustaceans and insects), calcification (millipedes) or both (crabs) In many crustaceans, the cuticle is hardened by incorporating aragonite or calcite but the segments that require maximum hardness are composed sclerotin. Cuticle: besides functioning as a skeleton, the cuticle must act as a waterproof covering in order to prevent these small animals from drying up.