Metabolisme: Perbedaan antara revisi

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== Xenobiotika dan metabolisme redoks ==
{{further|Xenobiotik|Metabolisme obat|Metabolisme alkohol|Antioksidan}}
{{further|Xenobiotik|Metabolisme obat|Metabolisme Alkohol|Antioksidan}}Seluruh organisme secara konstan terpapar oleh senyawa yang mereka tidak bisa gunakan sebagai nutrisi dan dapat berbahaya, jika berakumulasi di dalam sel karena tidak memiliki fungsi metabolis. Senyawa yang berpotensi membahayakan ini disebut xenobiotik.<ref>{{Cite journal|last=Testa|first=Bernard|last2=Krämer|first2=Stefanie D.|date=Oktober 2006|title=The Biochemistry of Drug Metabolism – An Introduction|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/cbdv.200690111|journal=Chemistry & Biodiversity|language=en|volume=3|issue=10|pages=1053–1101|doi=10.1002/cbdv.200690111|issn=1612-1880|access-date=2020-07-16|archive-date=2020-07-16|archive-url=https://web.archive.org/web/20200716081155/https://onlinelibrary.wiley.com/doi/abs/10.1002/cbdv.200690111|dead-url=no}}</ref> Xenobiotik, seperti [[Obat|obat sintetis]], [[Racun|racun alami]], dan [[antibiotik]] didetokfisikasi oleh serangkaian enzim metabolis.Pada manusia,termasuk di antaranya [[sitokrom P450 oksidase]],<ref>{{Cite web|url=https://www.eurekaselect.com/64118/article|title=The Cytochrome P450 Superfamily: Biochemistry, Evolution and Drug Metabolism in Humans|last=Danielson|first=P. B.|date=Desember 2002|website=Current Drug Metabolism|language=en|doi=10.2174/1389200023337054|access-date=2020-07-16|archive-date=2020-07-19|archive-url=https://web.archive.org/web/20200719213842/https://www.eurekaselect.com/64118/article|dead-url=no}}</ref><ref>{{cite journal|date=December 2002|title=The cytochrome P450 superfamily: biochemistry, evolution and drug metabolism in humans|journal=Current Drug Metabolism|volume=3|issue=6|pages=561–97|doi=10.2174/1389200023337054|pmid=12369887|vauthors=Danielson PB}}</ref> [[Glukuronosiltransferase|UDP-glukuronosiltransferase]],<ref>{{Cite web|url=https://www.eurekaselect.com/65538/article|title=UDP-Glucuronosyltransferases|last=King|first=C. D.|last2=Rios|first2=G. R.|date=Agustus 2000|website=Current Drug Metabolism|language=en|doi=10.2174/1389200003339171|access-date=2020-07-16|last3=Tephly|first3=M. D. Green and T. R.|archive-date=2020-07-16|archive-url=https://web.archive.org/web/20200716220241/https://www.eurekaselect.com/65538/article|dead-url=no}}</ref> and [[Glutation-S-transferase|glutation ''S''-transferase]].<ref>{{Cite journal|last=Sheehan|first=D.|last2=Meade|first2=G.|last3=Foley|first3=V. M.|last4=Dowd|first4=C. A.|date=November 2001|title=Structure, function and evolution of glutathione transferases: implications for classification of non-mammalian members of an ancient enzyme superfamily|url=https://pubmed.ncbi.nlm.nih.gov/11695986/|journal=The Biochemical Journal|volume=360|issue=Pt 1|pages=1–16|doi=10.1042/0264-6021:3600001|issn=0264-6021|pmc=1222196|pmid=11695986|access-date=2020-07-16|archive-date=2020-06-29|archive-url=https://web.archive.org/web/20200629191302/https://pubmed.ncbi.nlm.nih.gov/11695986/|dead-url=no}}</ref> Sistem ini terbagi menjadi tiga langkah. Langkah pertama ialah mengoksidasi xenobiotik (fase I) dan mengonjungasi gugus berbahan dasar air terhadap molekul (fase II). Xenobiotik larut air yang telah temodikasi dapat dipompa keluar dari sel dan organisme multiseluler akan mencerna lebih jauh, sebelum senyawa tersebut dieskresikan (fase III). Pada ilmu [[ekologi]], reaksi ini sangat penting dalam proses [[biodegradasi]] polutan oleh mikrob dan [[bioremediasi]] lahan yang terkontaminasi serta tumpahan minyak.<ref>{{Cite journal|last=Galvão|first=Teca Calcagno|last2=Mohn|first2=William W.|last3=Lorenzo|first3=Víctor de|date=Oktober 2005|title=Exploring the microbial biodegradation and biotransformation gene pool|url=https://www.cell.com/trends/biotechnology/abstract/S0167-7799(05)00223-4|journal=Trends in Biotechnology|language=English|volume=23|issue=10|pages=497–506|doi=10.1016/j.tibtech.2005.08.002|issn=0167-7799|pmid=16125262|access-date=2020-07-16|archive-date=2013-10-14|archive-url=https://web.archive.org/web/20131014174519/http://www.cell.com/trends/biotechnology/abstract/S0167-7799(05)00223-4|dead-url=no}}</ref> Banyak reaksi mikrob yang juga ada pada organisme multiseluler. Akan tetapi, dikarenakan diversitas jenis mikrob, organisme ini dapat menangani xenobiotik dalam jangkauan yang lebih luas dibandingkan dengan organisme multiseluler. Organisme ini juga dapat mendegradasi [[polutan organik persisten]] seperti senyawa [[organoklorida]].<ref>{{Cite journal|last=Janssen|first=Dick B.|last2=Dinkla|first2=Inez J. T.|last3=Poelarends|first3=Gerrit J.|last4=Terpstra|first4=Peter|date=2005|title=Bacterial degradation of xenobiotic compounds: evolution and distribution of novel enzyme activities|url=https://sfamjournals.onlinelibrary.wiley.com/doi/abs/10.1111/j.1462-2920.2005.00966.x|journal=Environmental Microbiology|language=en|volume=7|issue=12|pages=1868–1882|doi=10.1111/j.1462-2920.2005.00966.x|issn=1462-2920|access-date=2020-07-16|archive-date=2022-04-11|archive-url=https://web.archive.org/web/20220411023056/https://sfamjournals.onlinelibrary.wiley.com/doi/abs/10.1111/j.1462-2920.2005.00966.x|dead-url=yes}}</ref>
 
{{further|Xenobiotik|Metabolisme obat|Metabolisme Alkohol|Antioksidan}}Seluruh organisme secara konstan terpapar oleh senyawa yang mereka tidak bisa gunakan sebagai nutrisi dan dapat berbahaya, jika berakumulasi di dalam sel karena tidak memiliki fungsi metabolis. Senyawa yang berpotensi membahayakan ini disebut xenobiotik.<ref>{{Cite journal|last=Testa|first=Bernard|last2=Krämer|first2=Stefanie D.|date=Oktober 2006|title=The Biochemistry of Drug Metabolism – An Introduction|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/cbdv.200690111|journal=Chemistry & Biodiversity|language=en|volume=3|issue=10|pages=1053–1101|doi=10.1002/cbdv.200690111|issn=1612-1880|access-date=2020-07-16|archive-date=2020-07-16|archive-url=https://web.archive.org/web/20200716081155/https://onlinelibrary.wiley.com/doi/abs/10.1002/cbdv.200690111|dead-url=no}}</ref> Xenobiotik, seperti [[Obat|obat sintetis]], [[Racun|racun alami]], dan [[antibiotik]] didetokfisikasi oleh serangkaian enzim metabolis.Pada manusia,termasuk di antaranya [[Sitokrom P450|sitokrom P450 oksidase]],<ref>{{Cite web|url=https://www.eurekaselect.com/64118/article|title=The Cytochrome P450 Superfamily: Biochemistry, Evolution and Drug Metabolism in Humans|last=Danielson|first=P. B.|date=Desember 2002|website=Current Drug Metabolism|language=en|doi=10.2174/1389200023337054|access-date=2020-07-16|archive-date=2020-07-19|archive-url=https://web.archive.org/web/20200719213842/https://www.eurekaselect.com/64118/article|dead-url=no}}</ref><ref>{{cite journal|date=December 2002|title=The cytochrome P450 superfamily: biochemistry, evolution and drug metabolism in humans|journal=Current Drug Metabolism|volume=3|issue=6|pages=561–97|doi=10.2174/1389200023337054|pmid=12369887|vauthors=Danielson PB}}</ref> [[Glukuronosiltransferase|UDP-glukuronosiltransferase]],<ref>{{Cite web|url=https://www.eurekaselect.com/65538/article|title=UDP-Glucuronosyltransferases|last=King|first=C. D.|last2=Rios|first2=G. R.|date=Agustus 2000|website=Current Drug Metabolism|language=en|doi=10.2174/1389200003339171|access-date=2020-07-16|last3=Tephly|first3=M. D. Green and T. R.|archive-date=2020-07-16|archive-url=https://web.archive.org/web/20200716220241/https://www.eurekaselect.com/65538/article|dead-url=no}}</ref> and [[Glutation-S-transferase|glutation ''S''-transferase]].<ref>{{Cite journal|last=Sheehan|first=D.|last2=Meade|first2=G.|last3=Foley|first3=V. M.|last4=Dowd|first4=C. A.|date=November 2001|title=Structure, function and evolution of glutathione transferases: implications for classification of non-mammalian members of an ancient enzyme superfamily|url=https://pubmed.ncbi.nlm.nih.gov/11695986/|journal=The Biochemical Journal|volume=360|issue=Pt 1|pages=1–16|doi=10.1042/0264-6021:3600001|issn=0264-6021|pmc=1222196|pmid=11695986|access-date=2020-07-16|archive-date=2020-06-29|archive-url=https://web.archive.org/web/20200629191302/https://pubmed.ncbi.nlm.nih.gov/11695986/|dead-url=no}}</ref> Sistem ini terbagi menjadi tiga langkah. Langkah pertama ialah mengoksidasi xenobiotik (fase I) dan mengonjungasi gugus berbahan dasar air terhadap molekul (fase II). Xenobiotik larut air yang telah temodikasi dapat dipompa keluar dari sel dan organisme multiseluler akan mencerna lebih jauh, sebelum senyawa tersebut dieskresikan (fase III). Pada ilmu [[ekologi]], reaksi ini sangat penting dalam proses [[biodegradasi]] polutan oleh mikrob dan [[bioremediasi]] lahan yang terkontaminasi serta tumpahan minyak.<ref>{{Cite journal|last=Galvão|first=Teca Calcagno|last2=Mohn|first2=William W.|last3=Lorenzo|first3=Víctor de|date=Oktober 2005|title=Exploring the microbial biodegradation and biotransformation gene pool|url=https://www.cell.com/trends/biotechnology/abstract/S0167-7799(05)00223-4|journal=Trends in Biotechnology|language=English|volume=23|issue=10|pages=497–506|doi=10.1016/j.tibtech.2005.08.002|issn=0167-7799|pmid=16125262|access-date=2020-07-16|archive-date=2013-10-14|archive-url=https://web.archive.org/web/20131014174519/http://www.cell.com/trends/biotechnology/abstract/S0167-7799(05)00223-4|dead-url=no}}</ref> Banyak reaksi mikrob yang juga ada pada organisme multiseluler. Akan tetapi, dikarenakan diversitas jenis mikrob, organisme ini dapat menangani xenobiotik dalam jangkauan yang lebih luas dibandingkan dengan organisme multiseluler. Organisme ini juga dapat mendegradasi [[polutan organik persisten]] seperti senyawa [[organoklorida]].<ref>{{Cite journal|last=Janssen|first=Dick B.|last2=Dinkla|first2=Inez J. T.|last3=Poelarends|first3=Gerrit J.|last4=Terpstra|first4=Peter|date=2005|title=Bacterial degradation of xenobiotic compounds: evolution and distribution of novel enzyme activities|url=https://sfamjournals.onlinelibrary.wiley.com/doi/abs/10.1111/j.1462-2920.2005.00966.x|journal=Environmental Microbiology|language=en|volume=7|issue=12|pages=1868–1882|doi=10.1111/j.1462-2920.2005.00966.x|issn=1462-2920|access-date=2020-07-16|archive-date=2022-04-11|archive-url=https://web.archive.org/web/20220411023056/https://sfamjournals.onlinelibrary.wiley.com/doi/abs/10.1111/j.1462-2920.2005.00966.x|dead-url=yes}}</ref>
 
Masalah serupa untuk xenobiotik terjadi untuk [[organisme aerobik]] adalah [[stres oksidatif]].<ref>{{Cite journal|last=Rice-Evans|first=C.|last2=Halliwell|first2=B.|last3=Lunt|first3=G. G.|last4=Davies|first4=Kelvin J. A.|date=November 1995|title=Oxidative stress: the paradox of aerobic life|url=https://portlandpress.com/biochemsocsymp/article/doi/10.1042/bss0610001/50002/Oxidative-stress-the-paradox-of-aerobic-life|journal=Biochemical Society Symposia|language=en|volume=61|issue=|pages=1–31|doi=10.1042/bss0610001|issn=0067-8694|access-date=2020-07-16|archive-date=2020-07-17|archive-url=https://web.archive.org/web/20200717191837/https://portlandpress.com/biochemsocsymp/article/doi/10.1042/bss0610001/50002/Oxidative-stress-the-paradox-of-aerobic-life|dead-url=no}}</ref> Stres oksidatif dimulai dengan reaksi [[fosforilasi oksidatif]] dan pembentukan [[Disulfida|ikatan disulfida]] selama [[pelipatan protein]] yang menghasilkan [[spesi oksigen reaktif]], seperti [[hidrogen peroksida]] <ref>{{Cite journal|last=Tu|first=Benjamin P.|last2=Weissman|first2=Jonathan S.|date=Februari 2004|title=Oxidative protein folding in eukaryotes|url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2172237/|journal=The Journal of Cell Biology|volume=164|issue=3|pages=341–346|doi=10.1083/jcb.200311055|issn=0021-9525|pmc=2172237|pmid=14757749|access-date=2020-07-16|archive-date=2021-03-08|archive-url=https://web.archive.org/web/20210308102142/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2172237/|dead-url=no}}</ref> Oksidan yang bersifat merusak ini dihilangkan oleh metabolit antioksidan seperti [[glutation]] dan enzim [[Enzim katalase|katalase]] dan [[peroksidase]].<ref>{{Cite journal|last=Sies|first=H|date=Maret 1997|title=Oxidative stress: oxidants and antioxidants|url=http://doi.wiley.com/10.1113/expphysiol.1997.sp004024|journal=Experimental Physiology|language=en|volume=82|issue=2|pages=291–295|doi=10.1113/expphysiol.1997.sp004024}}</ref><ref>{{Cite web|url=https://www.eurekaselect.com/62686/article|title=The Antioxidants and Pro-Antioxidants Network: An Overview|last=Vertuani S|last2=Manfredini S|date=Mei 2004|website=Current Pharmaceutical Design|language=en|doi=10.2174/1381612043384655|access-date=2020-07-16|last3=Angusti A|archive-date=2020-07-16|archive-url=https://web.archive.org/web/20200716095751/https://www.eurekaselect.com/62686/article|dead-url=no}}</ref>