Why are all enzymes are proteins, but not all proteins are enzymes?

All enzymes are but not all proteins are enzymes.

Proteins are biological molecules that come in a wide variety of forms. They play a lot of different important roles in our bodies from being a structural part of cells (like the protein keratin in our hairs and nails) to messengers (in the form of hormones) in our body.

Enzymes are just one of the many functions of a protein. They help speed up life processes so our bodies can immediately receive their needs without disrupting other bodily chemical processes.