Difference Between L-glutamic Acid & L-glutamine

L-glutamic acid and L-glutamine have similar structures and play important roles in your body's functions. They are both amino acids that, according to Ray Sahelian M.D., are constantly assembled and broken down again to form different proteins and enzymes. These amino acids are needed to form muscle and provide energy to the cells in your small intestine. The FDA does not regulate their supplementation; talk to your doctor before trying L-glutamic acid or L-glutamine.

Amino Acids

Amino acids are a class of compounds that plays a vital role in your body; they function most notably to make protein, without which many tissues in the body, including muscle, could not form. Amino acids perform various other tasks and often are precursors and co-enzymes that fuel biochemical reactions in your body. Many molecules, particularly amino acids, are given an "L" or sometimes a "D" to denote their chirality. A chiral molecule is one that cannot be reversed -- its mirror-image molecule is treated differently by the body. An "L" stands for levo-rotary, meaning counterclockwise. Most supplements will have a chiral notation, although in scientific journals, when chirality is not relevant, the letter is often dropped.

L-Glutamic Acid

L-glutamic acid is made from a number of amino acids, including ornithine and arginine, states Healthvitaminsguide. Glutamic acid is a non-essential amino acid, meaning it is made by the body, a component of folic acid and a precursor to glutathione, a powerful antioxidant. The acid also is referred to as glutamate, which is its salt form. According to Chem-online, glutamic acid is involved in the metabolism of sugar and fatty acids, and works as a neurotransmitter in the brain, transporting potassium and detoxifying ammonia.

L-Glutamine

L-glutamine can be synthesized, or made, from glutamic acid. Glutamine is the most abundant free amino acid in the body, with most of it held in skeletal muscle cells, according to an October 2009 study in "The Journal of Nutrition." It is metabolized in the small intestine, where it is broken down and used as the main source of cellular fuel, making it important in the regulation of your GI tract. The study also states that glutamine is needed to fuel the cells of your immune system, and at times the kidney utilizes glutamine as well. It can be converted into glucose, or sugar, when your body requires it, and it also helps to maintain the acid/alkaline balance in the body, states Healthvitaminsguide.

Synthesis

Glutamic acid and glutamine are interconvertible, meaning that they can each make the other. Both compounds have a similar base chain of molecules; glutamine has an amide group while glutamic acid has a hydroxyl group attached to its chain. The study published in "The Journal of Health" contains a diagram showing the addition of an amide group to glutamic acid to form glutamine, and the cleaving of an amide group from glutamine to make glutamic acid. Depending on available energy and enzymes, the body can make use of either substance as function demands.

Supplementation

In regards to supplementation, L-glutamine and L-glutamic acid are typically used by athletes and bodybuilders to promote muscle growth. L-glutamine also might be of use post-surgery; according to Healthvitaminsguide, after surgery or extreme illness, up to one-third of muscle stores of glutamine are released for nervous system use. This release can lead to loss of muscle mass. L-glutamic acid is considered excitatory, meaning tending to induce excitation, so talk to your doctor before trying either L-glutamine or L-glutamic acid as a supplement.