Final answer:
Matrix metalloproteinases are the family of enzymes that break down extracellular matrix proteins with the aid of a zinc ion cofactor. These enzymes are essential for various biological processes such as tissue remodeling and wound healing.
Step-by-step explanation:
The family of enzymes that can break down extracellular matrix proteins and require a zinc ion cofactor are called Matrix metalloproteinases (MMPs). These enzymes are part of a larger class of enzymes known as metalloproteins, which contain metal ions tightly bound to amino acid side chains. Matrix metalloproteinases are vital for tissue remodeling, wound healing, and in pathological processes such as tumor invasion and metastasis. They require a zinc ion (Zn++) as a cofactor, which is essential for their enzymatic activity. This aspect of enzymatic structure is an example of how apoenzymes require cofactors, like metal ions, to form active holoenzymes for optimal functionality.