1  Amino acids build proteins, and proteins are life-sustaining macronutrients. Yet simply calling amino acids the building blocks of protein doesn’t do justice to their value. While some amino acids only make proteins, others fill a variety of roles, from supporting metabolism to protecting your heart. Your body can also use amino acids for energy when you lack carbs and fats.

The human body requires glucose for some of its most important functions. This simple sugar provides the energy needed to perform specialized processes such as digestion and cellular respiration. Problems with the amount of glucose in the blood result in serious complications that could lead to coma or even death if not corrected quickly.
Amino acids build proteins and proteins are life-sustaining nutrients
Glucose is the source of energy.