BCAA vs .Free Form Amino Acids?

I see a lot of people taking the Branched amino acids compared to the free form of amino acids? Currently I’m taking the free form, made by Ultimate Nutrition. I like this brand over some others because it contains 8 of the essential AA and 10 of the non essential. Most one’s I see at the store only have 4 types of Amino Acids.

Can somebody clue me into why BCAA seem more popular? Posibly explain the positives versus the Negatives?

Give me good details too, I’m a biomedical science graduate with big background in biochem and physiology. It’s just that we never covered amino acid supplements…

Thanks T-Nation

BCAA: Brandched Chain Amino Acids: Luecine, Isoluecine, Valine: The 3 amino acids which make up 1/3 of muscle tissue. The theory behind BCAA supplementation is to overload the livers ability to utilize BCAAs, I think I read the liver can handle 3-5g at once. Once the liver is no longer able to keep up the rest of the AAs will circulate through the blood. Luecine triggers and insulin response, an especially large one when coupled with carbohydrate. Insulin + boatload of circulation AAs ideally saturates the muscles with the AAs they need to repair and rebuild their tissues.

I hope that helped.