Some of the new plastics are formulated to be biodegradable and many of them are made from byproducts of agriculture and industry that we now throw away or burn as garbage. Polymers Plastics are one class of the chemical group called polymers . Polymers are giant molecules made up of long chains of simple molecules. Some polymers look like box cars in a train while others are more complex and look like branches or nets. Many important substances found in nature are polymers.
Proteins are polymers.
Proteins carry smaller, vital molecules around your body, are necessary for digestion, and are major components in skin, bones and muscles. Another polymer, cellulose, is the primary component in plant cell walls. Starch, another polymer, is a food source that most plants store in their cells. Lignin is another naturally occurring polymer. It gives plants strength and breaks down very slowly.