What are the repeated units within a polymer molecule that act as building blocks of long-chain molecules called?

The repeated units within a polymer molecule that function as building blocks for long-chain structures are known as mers. Mers are the fundamental structural units that link together to form the larger, more complex polymer chains. Each mer reflects a basic repeating unit that maintains specific chemical properties which contribute to the overall characteristics of the polymer.

In the context of polymer chemistry, while monomers are the individual molecules that can join together to form polymers, the term 'mers' specifically refers to these repeating units once they have been incorporated into a polymer chain. As a result, the distinction between mers and monomers is significant when discussing the structural aspects of polymers.

Radicals are typically reactive species in chemistry that have unpaired electrons and are not relevant in this context. Additives refer to substances that are added to polymers to enhance their properties or performance, rather than serving as the basic building blocks of the polymer itself. Thus, 'mers' appropriately captures the concept of repeating building units in polypeptide structures.