Glucogenic amino acid
Aglucogenic amino acid(orglucoplastic amino acid[1]) is anamino acidthat can be converted intoglucosethroughgluconeogenesis.[2][3]This is in contrast to theketogenic amino acids,which are converted intoketone bodies.
The production of glucose from glucogenic amino acids involves these amino acids being converted toalpha keto acidsand then to glucose, with both processes occurring in the liver. This mechanism predominates duringcatabolysis,rising asfastingandstarvationincrease in severity.
As an example, consider alanine.Alanineis a glucogenic amino acid that the liver's gluconeogenesis process can use to produce glucose.
Muscle cells break down their protein when their blood glucose levels fall, which happens during fasting or periods of intense exercise. The breakdown process releasesalanine,which is then transferred to the liver. Through atransaminationprocess, alanine is changed into pyruvate in the liver. Following this, pyruvate is transformed intooxaloacetate,a crucial step in thegluconeogenesisprocess.[4]It is possible to synthesize glucose from oxaloacetate, ensuring that the blood glucose levels required for the body to produce energy are maintained.
In humans, the glucogenic amino acids are:
- Alanine
- Arginine
- Asparagine
- Aspartic acid
- Cysteine
- Glutamic acid
- Glutamine
- Glycine
- Histidine
- Methionine
- Proline
- Serine
- Valine
Amino acids that are both glucogenic and ketogenic, known as amphibolic (mnemonic "PITTT" ):
Onlyleucineandlysineare not glucogenic (they are onlyketogenic).
Glucogenic and ketogenic amino acids are classified according to the metabolic pathways they enter after being broken down. Glucogenic amino acids can be converted into intermediates that feed the gluconeogenesis metabolic pathway, which produces glucose. When necessary, these amino acids can be used to generate glucose. As previously stated, because they can be transformed into glucose via a variety of metabolic pathways, the majority of amino acids (apart from leucine and lysine) are regarded as glucogenic. Alternatively, the breakdown of ketogenic amino acids results in the ketogenic precursors acetyl-CoA and acetoacetate. These substances undergo a process calledketogenesisthat produces ketone bodies like acetoacetate, beta-hydroxybutyrate, and acetone.[5]
See also
[edit]References
[edit]- ^Müller, M. J.; Seitz, H. J. (1984). "Thyroid hormone action on intermediary metabolism. Part III. Protein metabolism in hyper- and hypothyroidism".Klinische Wochenschrift.62(3): 97–102.doi:10.1007/BF01738699.PMID6231411.S2CID2598447.
- ^Brosnan J (1 June 2003)."Interorgan amino acid transport and its regulation".J Nutr.133(6 Suppl 1): 2068S–2072S.doi:10.1093/jn/133.6.2068S.PMID12771367.
- ^Young V, Ajami A (1 September 2001)."Glutamine: the emperor or his clothes?".J Nutr.131(9 Suppl): 2449S–59S, discussion 2486S–7S.doi:10.1093/jn/131.9.2449S.PMID11533293.
- ^"Glucogenic Amino Acid - an overview | ScienceDirect Topics".www.sciencedirect.com.Retrieved2023-12-08.
- ^D'Andrea, Gabriele (January 2000)."Classifying amino acids as gluco(glyco)genic, ketogenic, or both".Biochemical Education.28(1): 27–28.doi:10.1111/j.1539-3429.2000.tb00007.x.
External links
[edit]- Amino acid metabolism
- Chapter on Amino acid catabolism inBiochemistryby Jeremy Berg, John Tymoczko, Lubert Stryer. Fourth ed. by Lubert Stryer.ISBN0-7167-4955-6Accessed 2007-03-17
- Amino acid metabolism
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