What are non-essential amino acids?

Non-essential amino acids are those amino acids that the body can synthesize on its own, meaning they do not necessarily need to be obtained directly through dietary sources. The body has the ability to produce them through various metabolic pathways using other compounds, such as other amino acids or molecules derived from carbohydrate or fat metabolism.

While some of the other choices address important aspects of amino acids, they do not accurately define what non-essential amino acids are. Non-essential amino acids may play a role in muscle growth and can be utilized for energy, but these functions do not determine their classification as non-essential. The key characteristic that identifies them is their availability from internal synthesis rather than the necessity to acquire them from food sources.