Protein is a fundamental macronutrient essential for building, repairing, and maintaining virtually all tissues in the human body.
From a nutritional and biochemical perspective, here is how protein is defined:
1. Molecular Structure
At its core, protein is composed of smaller building blocks called amino acids, which are linked together in long chains. There are 20 different amino acids that your body uses. They are categorized into two main groups:
• Essential Amino Acids (EAAs): There are 9 essential amino acids that your body cannot make on its own. They must come from your diet. As seen on the label of the Rule 1 Casein Protein tub in the photo, a quality protein powder often highlights its EAA content (this one contains 11g of EAAs per serving).
• Non-Essential Amino Acids: These are amino acids