Question

Which amino acid is responsible for signaling for muscle protein synthesis, and is the only amino acid independently capable of enhancing muscle anabolism?

Answer 1

Leucine is the amino acid known to signal muscle protein synthesis and enhance muscle anabolism independently, distinguishing itself from other amino acids, including glutamine, which lacks significant effects in supplementation studies.

Step-by-step explanation:

The amino acid responsible for signaling for muscle protein synthesis and the only one independently capable of enhancing muscle anabolism is leucine. Leucine is one of the three branched-chain amino acids (BCAAs) which also include isoleucine and valine. BCAAs are unique in that they are metabolized directly in the muscles, offering anabolic and anti-catabolic effects. The role of leucine in muscle protein synthesis is well documented, and it is considered a key regulator of this process.

Glutamine, although the most abundant amino acid in human muscle, has not shown significant effects on muscle anabolism when supplemented compared to a placebo in several studies. In contrast, leucine, due to its capacity to stimulate the synthesis of muscle proteins, stands out among amino acids.