Main article: Nicotinic acetylcholine receptors. The nAChRs are ligand-gated ion channels, and, like other members of the cys-loop ligand-gated ion channel superfamily, are composed of five protein subunits symmetrically arranged like staves around a barrel.
Acrylonitrile butadiene styrene, otherwise known as ABS plastic, is a lightweight material popularly used in children's toys. There are two types: one suited for extrusion molding and one for injection molding. LEGO blocks are made from ABS plastic because it is so light and durable. Continue Reading.
Number 2. Number 2 plastics are made out of high-density polyethylene (HDPE) and are very versatile. These plastics are stiff and have good barrier properties. They are useful in the packaging of short shelf-life products like milk, and hard plastic products such as those used in plumbing.