ACE (Angiotensin-Converting Enzyme): ACE is a key enzyme in the Renin-Angiotensin System (RAS) that helps regulate blood pressure and fluid balance. It converts angiotensin I into angiotensin II, a powerful vasoconstrictor that affects blood vessel tone, electrolyte levels, and stimulates aldosterone release. ACE also plays important roles in heart function, kidney health, and inflammatory processes. Imbalances in ACE activity are linked to conditions such as hypertension, heart failure, and kidney disease.