Ascientist has discovered a new macromolecule in mice. he determines that this macromolecule contains a unique combination of 20 distinct monomers, folds into an intricate three-dimensional shape, and is involved in a distinct chemical reaction. this scientist has likely discovered a

This scientist has likely discovered a protein.

Explanation:

Proteins are complex molecules composed of monomers known as amino acids. They usually have complex structures that makes them fold. Proteins have several functions but they are essential for body functions because they act as biological catalysts in which they speed up chemical reactions.

nucleus

would be most reasonable answer tbh

a covalent bond, specfically triple bond