Tryptophan

An essential amino acid

Tryptophan is an essential amino acid that is important in human nutrition. It is a precursor to several important biomolecules, including serotonin, melatonin, and niacin.

Structure and properties

Tryptophan is an _-amino acid with the chemical formula C__H__N_O_. It contains an indole functional group, which is a bicyclic structure consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. This structure is responsible for tryptophan's unique properties and its role in various biological processes.

3D model of tryptophan

Biosynthesis

Tryptophan is synthesized in plants and microorganisms from chorismate and anthranilate. The biosynthesis involves several enzymatic steps, including the conversion of chorismate to anthranilate, followed by a series of reactions that lead to the formation of tryptophan.

Biosynthesis of tryptophan

Metabolism

In humans, tryptophan is metabolized through several pathways. One of the primary pathways is the kynurenine pathway, which leads to the production of nicotinamide adenine dinucleotide (NAD_), an essential coenzyme in cellular metabolism. Tryptophan is also a precursor to serotonin, a neurotransmitter that plays a role in mood regulation, and melatonin, a hormone involved in sleep regulation.

Metabolism of tryptophan

Dietary sources

Tryptophan is found in various dietary sources, including turkey, chicken, milk, cheese, yogurt, eggs, fish, and nuts. It is often associated with the myth that consuming turkey leads to increased sleepiness due to its tryptophan content, although the effect is more likely due to the overall meal composition.

Health implications

Tryptophan supplementation has been studied for its potential effects on mood disorders, such as depression and anxiety, due to its role in serotonin production. However, excessive intake of tryptophan supplements can lead to health issues, such as eosinophilia-myalgia syndrome.

Related pages

• Amino acid
• Serotonin
• Melatonin
• Niacin

References

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  Tryptophan molecule spinning
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  Tryptophan metabolism pathway
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  Tryptophan biosynthesis process