1. Building and repairing tissues: Protein is the building block for all of our cells and tissues. It's involved in the growth and repair of everything from muscles to skin to bones.

2. Producing enzymes and hormones: Many enzymes and hormones are made up of protein. These substances regulate various bodily functions, including metabolism, digestion, and immunity.

It's important to note that protein also plays a role in other functions, such as:

* Maintaining fluid balance

* Transporting nutrients

* Providing energy (though it's not the body's primary energy source)

So, while the two primary uses are building and repairing tissues, and producing enzymes and hormones, protein is involved in many other critical bodily functions.