Anatomy and Physiology II Practice Test 2026 - Free Anatomy Practice Questions and Study Guide

Nonessential amino acids are the type of amino acids that the body can synthesize from other amino acids, meaning they do not need to be obtained directly from the diet. The body has metabolic pathways that convert certain amino acids into nonessential ones, allowing it to maintain necessary levels even if those amino acids are not consumed in food.

Essential amino acids, on the other hand, cannot be synthesized by the body and must be obtained through dietary sources. Conditional amino acids are usually classified as nonessential, but they can become essential in certain situations, such as during periods of stress, illness, or rapid growth. Branched-chain amino acids refer specifically to a group that includes leucine, isoleucine, and valine, which are essential and must be consumed through the diet. Thus, nonessential amino acids have a unique role as the body's adaptable components that ensure a balanced supply regardless of dietary intake.