There are 300 naturally occurring amino acids (AA) but only twenty take part in the formation of proteins, plants as well as animals in origin. They are working substances in all cells. They make the protein more complex. They are linked by peptide bonds. They are also classified according to our body needs into essential and non-essential amino acids.
Essential ones are those which the body cannot make and they must be provided by the food. These are histidine, leucine, isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
Non-Essential are those which the body can make, these are alanine, arginine, asparagines, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
Although all of them share a common structure, they differ in size, shape, electrical charge, and other characteristics because of differences in their side chains. The amino acid sequence can be explained as follow; if a person is to walk along a polypeptide chain, each stepping stone will be one of the 20 odd different AA. The first step stone may be methionine. The second may be an alanine. The third may be a glycine and a fourth a tryptophan and do on. Walking along another polypeptide path, a person may step on proline, then valine. It also describes that their sequence within the protein varies.
Even though they are needed to do the work that only they can perform i.e. build vital proteins but they can be sacrificed to give energy and glucose if needed. They can be used to make fats e.g. if the person eats too much protein than his body needs, AA is deaminated, the nitrogen is excreted and the remaining carbohydrate fragments are converted to fats and stored for later use.
They are even helpful in evaluating the food’s protein quality. They can further be used to make other essential compounds. Likewise, they have a wide range of effects, particularly important effects on the brain areas given.
Effects of DL-Phenylalanine and L-Glutamine Amino Acids over the Brain.
DL-phenylalanine: is a nutritional supplement and acts as an analgesic and anti-depressant. It is actually the mixture of D-phenylalanine and L- phenylalanine.
It provides an analgesic effect by acting on the brain. It does so by blocking the degradation of DL-phenylalanine of endorphin with the help of the enzyme carboxypeptidase.
As we know L-phenylalanine is a precursor in the synthesis of epinephrine and norepinephrine and decreased levels of them result in depression in an individual. So its antidepressant effect is because it blocks endorphin degradation, this thing leads to inhibition of GABA in the midbrain and the result is increased dopamine release.
L-Glutamine: It is also a nutritional supplement and it can easily enter the brain where it is used for energy and is a precursor to nerve transmitters both excitatory and inhibitory. If the brain does not get glucose, glutamine can be metabolized for energy by the brain as compensation. L-Glutamine also plays an important role during stress and in optimum protein metabolism and utilization both in the brain as well as in the gastrointestinal system. People who use them often report being happy and energetic and less fatigue.