Témbongkeun sumber pikeun Laktosa

[[Gambar:Beta-D-Lactose.svg|thumb|Wangun molekul laktosa.]]
'''Laktosa''' nyaéta [[gula]] nu aya dina [[susu]] (ku kituna katelah '''gula susu'''), kadarna 2–8% (dumasar beurat), béda-béda di unggal sato. Ngaran sistematisna β-D-galaktopiranosil-(1↔4)β-D-glukopiranosa. Laktosa bisa diékstrak tina [[dadih]].

== Kimia ==
Laktosa kaasup [[disakarida]] nu ngandung β-D-[[galaktosa]] jeung fragmén α/β-D-[[glukosa]] maké beungkeut β1-4 [[glikosida]].

=== Kelarutan ===
Kelarutanana dina cai 18.9049&nbsp;g (25&nbsp;°C), 25.1484&nbsp;g (40&nbsp;°C), jeung 37.2149&nbsp;g (60&nbsp;°C) per 100&nbsp;g larutan. Kelarutanana dina [[étanol]] 0.0111&nbsp;g (40&nbsp;°C) jeung (0.0270&nbsp;g (60&nbsp;°C) per 100&nbsp;g larutan<ref name="path">{{cite journal
 | year = 20001
 | last = Machado
 | first = José J.B.
 | coauthors = João A. Coutinho, Eugénia A. Macedo
 | url = http://path.web.ua.pt/file/FPE%20(2000)%20173%20121.pdf
 | title = Solid–liquid equilibrium of a-lactose in ethanol/water
 | format = PDF
 | publisher = Fluid Phase Equilibria
 | accessdate = 2007-12-05
}}</ref>.

== Katabolismeu laktosa ==
{{utama|Intoléransi laktosa}}
Anak [[mamalia]] nyusu ka indungna, susuna ngandung loba laktosa. [[Intestinal villus]] nyékrésikeun [[énzim]] nu katelah [[laktaseu]] (β-D-galaktosidaseu) pikeun nyerna ieu karbohidrat, ku cara megatkeun laktosa jadi dua sub-unitna: gula basajan [[glukosa]] jeung [[galaktosa]] anu bisa diserep. ku sabab laktosa mah lolobana aya dina susu, produksi laktaseu mamalia biasana nyirorot luyu jeung umurna.

Awak jalma-jalma turunan [[Éropa]], [[Timur Tengah]], [[India]], jeung sawaréh [[Afrika Wétan]] biasana masih ngahasilkeun laktaseu nepi ka sawawa, ku kituna tara aya masalah nalika maranéhna nginum susu [[sapi]], [[embé]], jeung [[domba]] atawa katuangan turunanana. Jalma nu intoléran kana laktosa teu bisa loba teuing ngonsumsi laktosa, sabab awakna teu bisa nyerna laktosa. Balukarna bisa jadi mules, [[muncrut]], jeung gangguan beuteung lianna<ref name="NYT">
{{cite news
| author= Nicholas Wade
| title= Study Detects Recent Instance of Human Evolution
| date= [[10 Désémber]] [[2006]]
| publisher= ''[[The New York Times]]''
| url= http://www.nytimes.com/2006/12/10/science/10cnd-evolve.html?
| accessdate= 2007-12-05
}}</ref>.

== Rujukan ==
* ''[[:en:Lactose|Lactose]]'' (dicutat 27 Agustus 2009)
{{reflist}}

{{Karbohidrat}}
{{pondok}}

[[Kategori:Disakarida]]