BCAAs vs free-form amino acids in diet.

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BCAAs vs free-form amino acids in diet.

Post by silligcam » Tue Feb 24, 2009 6:27 pm

I looked all over the internet and cant seem to find a good answer on this, a biologist has to know.

I work out. I take a whey protein supplement. The whey protein is made of branched chain AAs. On the back of the can, it has a chart of the typical amino acid masses that are in the average serving. For example, it says that there is 450mg of Tryptophan per serving.

When Tryptophan is taken in its free-form, 450mgs would have very noticable mental effects because my body would convert it into serotonin. However, when I take the tryptophan, as a BCAA in the whey, there are no mental effects.

Someone told me that free-tryptophan wouldn't cause mental effects. I disagree though. I'll provide this additional example though. I once took free-form l-phenylalanine (around 500mgs) which is a pre-cursor to neurotransmitters like dopamine, noradrenaline, and adrenaline. I noticed a strong mental excitation effect. Yet, there is almost a gram per serving of l-phenylalanine in the whey and I don't notice these effects.

I realize that my body uses amino acids for other chemical synthesis besides protein. It seems though, that my body would prefer to use a free-form amino acid for these non-protein purposes.

Is this true? Does the body primarily use free-form amino acids for non-protein purposes. It certainly seems that way from my experience.

Thanks for any replies!

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Re: BCAAs vs free-form amino acids in diet.

Post by hauischaui » Sat Jul 31, 2010 10:08 pm


im looking forward to answer your question!

Amino acids and the brain is a very complex issue. You should know , that there are is a
special protein , which transports amino acids in the brain. Free amino acids in the blood
compete for this transporter. Like tryptophan , phenylalanine and tyrosine have the bcaa
also an effect on one´s mood , but in a negative way. They darkens one´s mood.
An amino acid which concentration is high will reach the brain more likely , than a amino
acid in the blood stream , which concentration is higher. When you take phenylalanine , tyrosine
or tryptophan alone , and not in bond with other amino acids as whey , they will reach a very
high concentration in your blood. And when you feel the effect of the "good mood amino acids"
you have taken alone , you will know that they have displaced the competing amino acids
(bcaas) from the transporter....

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Post by JackBean » Sun Aug 01, 2010 12:43 pm

branched amino acids are different from Trp, they are Ile, Leu etc., but the Trp is not conjugated with them. And if it was, it wouldn't be used for proteosynthesis per se

Cis or trans? That's what matters.

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