Serotonin the neurotransmitter

Serotonin i.e. 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter that is said to be helping to relay signals from one area of the brain to another. However its primary functions are found in gastrointestinal tract as 90% of total serotonin is located in the enterochromaffin cells in the gut. 

Serotonin is made via a unique biochemical conversion process that begins with Tryptophan. Tryptophan is a building block to proteins. In the synthesis of serotonin, Tryptophan hydroxylase the enzyme combines with tryptophan to form 5-hydroxytryptophan metabolite that later converts to Serotonin.

Via wikipedia.org

As mentioned earlier serotonin helps to distribute messages across the brain. Brain cells related to mood, appetite, sleep, memory, learning, temperature regulation, sexual desire and some social behaviour are influenced either directly or indirectly by serotonin due to the widespread distribution in the brain. 

It can also affect the functioning of the cardiovascular system, muscles, and various elements in the endocrine system.

When it comes to mental health, it is widely believed that a serotonin deficiency plays a role in depression but there is no way to measure its levels in the living brain. Therefore, there have not been any studies proving that brain levels of this or any neurotransmitter are in short supply when depression or any mental illness develops. People who suffer from depression shows lower serotonin levels in blood levels but still it is not revealed that whether the blood levels reflect the brain's level of serotonin.

Antidepressant medications such as SSRIs (selective serotonin reuptake inhibitors) and SNRIs (serotonin and norepinephrine reuptake inhibitors) that work on serotonin levels are believed to lower the symptoms of depression, but their exact function is not fully understood.

Recent studies show that when the Mycobacterium vaccae, which occurs naturally in soil and is often breathed in when spending much time nature, is injected into mice, it stimulates neuron growth and causes serotonin levels in blood to increase. So that the bacteria could have antidepressant benefits but it is not yet revealed whether it has an effect on human.

Preparation of Sodium Carbonate extract - Identify Sulfates, Nitrites, Nitrates and Phosphates by using the prepared Sodium carbonate solution

Preparation of Sodium Carbonate extract

200mg of the unknown sample, 1g of Na₂CO₃ and 50ml of distilled water was added into a clean dry flask later boiled using a tripod stand. This was done by clamping a funnel above the flask to reduce evaporation.

It was boiled for about 5 minutes.

Afterwards solution was cooled and filtered using a filter paper.

A colorless filtrate was obtained.

Identify Sulfates, Nitrites, Nitrates and Phosphates by using the prepared Sodium carbonate solution

SO₄^2-

Procedure	Observation
5 drops of Na2CO3 extract was acidified with dil. HCl in boiling tube. Acidity was checked with litmus. It was kept in a hot water bath for about 3 minutes and added 3 drops of BaCl2	When the extract was acidified with HCl, it turned into brownish red colour. White colour precipitate was formed.

NO₂^-

Procedure	Observation
1ml of Na2CO3 extract was heated with dil. H2SO4 in boiling tube. The evolved gas was checked with starch.iodide paper.	With H2SO4 the extract turned into reddish brown colour. Brown fume was evolved when heating. It turned the starch-iodide paper into blue colour.

NO₃^-

Procedure	Observation
1ml of Na2CO3 extract was heated with 100mg Sulphamic acid in a boiling tube. Later dil.NaOH was added and heated until the evolution of NH3 is ceased. It was again checked with Devarda’s alloy.	In the presence of Sulphamic acid the solution turned into brownish red. Pungent smelling brownish colour gas was formed and the it continued for awhile in Devarda’s alloy.

PO₄^3-

Procedure	Observation
1ml of Na2CO3 extract, 1ml of dil. HNO3 and 10ml ammonium molybdate was heated gently in a boiling tube.	With HNO3 the extract turned into brownish red colour. Later a yellow colour precipitate was obtained.

What’s the purpose of preparing Na₂CO₃ extract?

It gives an expedient way of bringing all the anions of the sample into solution. Otherwise they might be insoluble and couldn’t carry out the experiment properly. Also it prevents the cation in interfering.

What is the importance of Na₂CO₃ extract to be clear and colourless?

This provides a better setting to observe formations of precipitates, colour changes which take place during the experiment.

Is the Na₂CO₃ extract basic or acidic?

It is slightly basic.

Basis of biochemical tests; Biuret test, Benedict test, Iodine/potassium iodide test, Emulsion test

Biuret test
A test for peptide bonds to identify proteins.

In the presence of dil.copper sulphate in alkaline solution, nitrogen atoms in the peptide chain form a purple complex with copper(ll) ions. Biuret is a compound derived from urea which also contains the –CONH- group and  gives a positive result.

Benedict test

A test for sugar

Reducing sugars- Benedict’s solution contains copper sulphate. Reducing sugars reduce soluble blue copper sulphate. Here the containing copper(ll) ions will change to insoluble red- brown copper oxide containing copper(l). This is seen as the precipitate.

Non-reducing sugars- The disaccharide will hydrolysed to its monosaccharide elements by boiling with dil. HCl. Such as Sucrose will be hydrolysed to glucose and fructose which are both reducing sugars. That will give the reducing sugar results with the Benedict’s test.

Iodine/potassium iodide test

A test for starch.

What is given at last is a poly-iodide complex formed with starch.

Emulsion test

A test for Lipids

Lipids are iinsoluble with water. Adding water to a solution of the lipid in alcohol results in an emulsion of lipid droplets or micelles in the water. These reflect light and give a white, opalescent appearance.