Talk:Lactase

This entry looks bad and misleading. "humens" is misspelled badly
This entry looks bad. "humens" is misspelled badly, the entry claims "most humans are lactose intolerant" which is misleading. FruitSalad4225 (talk)


 * Well spelling is to be corrected not complained about (there is an edit button for a reason!), and I don't see what is misleading about most humans being lactose intolerant, please explain?

--BerserkerBen 03:35, 16 November 2005 (UTC)


 * Because most humans are not lactose intolerant.

FruitSalad4225 (talk) 23:42, 1 July 2012 (UTC)


 * Is 70% not a majority?

Roy Lewis (talk) 20:27, 19 May 2020 (UTC)

Units of measure
Labels on lactase bottles often differ to make comparison difficult. Here's a first stab at a table, which should eventually be posted to the main article.
 * 375 mg = 5,250 FCC units
 * 200 LAC = ???
 * 1 Lac. U. = 1 ALU = 1 FCC unit.

It is more difficult to give an exact equivalence between milligrams (mg) and FCC units, but 125 mg should be sufficient as several companies list it as equal to 1750 FCC units.

-- Quest out of UK shows 2000 ALU per 200mg tablet of Lactase enzyme. — Preceding unsigned comment added by 41.220.239.226 (talk) 17:51, 27 September 2020 (UTC)

β-galactosidase
I think sufficient detail should be placed to explain why β-galactosidase and lactase are not one in the same, as can be see we already had people making that confusion. It should be well explained that lactase is part of the family of β-galactosidase, that lactase is specific to lactose while other β-galactosidases is specific to one or many other galactosides. --BerserkerBen 19:18, 22 December 2005 (UTC)


 * I created the β-galactosidase page so that if people are confused they can follow the link. All that needs to be said on this page is that Lactase is a type of β-galactosidase. Bensaccount 19:22, 22 December 2005 (UTC)


 * I don't think a link is enough to answer the confusion, I have seen the mistake made enough (on the internet in general) to make me believe it is warranted to explain that in detail, perhaps it could be stated as:


 * “Lactase is a beta galacticidase that can hydrolysis the beta 1,4 ether bridge of lactose”


 * and


 * “A common mistake is the assumption that all beta galacticidase enzymes are lactase enzymes, this is untrue as other beta galacticidases have substrates other then lactose.”


 * --BerserkerBen 20:24, 22 December 2005 (UTC)


 * BerserkerBen, this is what you got initially

'''Lactase is a member of the β-galactosidase family of enzyme: enzymes that hydrolysis β 1,4 bonded attachments off of galactose. Lactase (EC 3.2.1.23) is involved in the hydrolysis of lactose in to constituent galactose and glucose monomers. Not all β-galactosidase hydrolysis lactose, but those that can quilify as lactase enzymes.'''

If someone makes a wrong assumptiion it is their mistake not yours, at least i don't make such an assumption. You have done the right thing by creating the β-galactosidase family page, if they don't know what β-galactosidase is they can just follow the link - you don't have to explain it for them in every article that's about the members of this family. So this part of the text is unnecesary:

"Lactase is a member of the β-galactosidase family of enzyme: enzymes that hydrolysis β 1,4 bonded attachments off of galactose. Lactase (EC 3.2.1.23) is involved in the hydrolysis of lactose in to constituent galactose and glucose monomers. Not all β-galactosidase hydrolysis lactose, but those that can quilify as lactase enzymes."

Then you are left with two sentences that can be merged:

"Lactase (EC 3.2.1.23) , is a member of the β-galactosidase family of enzyme: enzymes that hydrolysis β 1,4 bonded attachments off of galactose. Lactase (EC 3.2.1.23) is involved in , catalyzes the hydrolysis of lactose in to constituent galactose and glucose monomers. Not all β-galactosidase hydrolysis lactose, but those that can quilify as lactase enzymes."

By the way, would you like to join our team? -- Boris 21:53, 22 December 2005 (UTC)


 * ok (?) I was speaking of the issue of the common confusion of lactase as all beta galacticidases, which I think is only a issue with lactase, I think that issue should be mentioned as it is relavent to lactase, if anyone wants to suggest how to do that please state so simply, by the way I'm not Bensaccount, just encase you didn't know. Previously (upthere) I made a suggested solution do you think its is viable?


 * I think saying it is a member of the β-galactosidase is sufficient to clear up this confusion. Bensaccount 23:56, 22 December 2005 (UTC)

I don't, we don't need to explain the diffrence between beta galacticidase and lactase, but we do need ot explain that the missconception exist, and until you people talk out argeement with me in here instead of editing first I will fight it. Now as I stated before here is the solution I propose, state if you argee/disargee or what you want changed:

“Lactase is a beta galacticidase that can hydrolysis the beta 1,4 ether bridge of lactose”

and

“A common mistake is the assumption that all beta galacticidase enzymes are lactase enzymes, this is untrue as other beta galacticidases have substrates other then lactose.”--BerserkerBen 02:23, 23 December 2005 (UTC)

This article provides an encyclopedia type of info, which means that there should not be any text that tries to clear up any misconception that the reader might have, but even if you insist so much this case has to go to the β-galactosidase because if you put it here, then you have to put it in all the articles about all those β-galactosidase that some people might think are lactases too, so we gonna end up with the same text in several articles, instead of being in just one place - now how does that make sence to you? So i strongly preffer to have either mine, Bensaccount or your first variant in the article. And then why do you keep writing "galacticidase"? Your variant though needs some fixing - when an enzyme has only one substrate it is more proper to say "it catalyzes this reaction" instead of "it can catalyze...", can is not used when you talk about the default function of a protein, especially when it takes place most of the time, it just doesn't "sound" right, and i'm not talking as some grammar pro, it's that i have read probably a half a dozen different biochemistry books and hundreds of articles and the authors don't say it that way, can sounds better when its used to describe an optional function, anyway that's up to you. Then you have this "beta 1,4 ether bridge" - this is not an ehter bond (bridge is very un-pro, so i won't let you use it), it is a glycoside bond, these are two different type of bonds, and although some authors might find them equivalent, they are not. -- Boris 09:44, 23 December 2005 (UTC)
 * Do you have any links to prove that this is a "common mistake"? Because i don't think it is, well at least i don't remember me or any of my colleagues having this problem while we were taking our biochemistry class. When you say "but we do need ot explain that the missconception exist", by "we" you mean yourself only, everyone on Wikipedia or who? For me it seems that we includes you only and noone else so far, and definately does not include me and at least one more guy, Bensaccount, because we, which in this case is me and Bensaccount, don't think that this explanation needs to take place here.
 * We have many articles on the site which address myths and miconceptions related to their topic, don't believe me then just search for "misconceptions". Yes I can find many examples of the error on the internet:

http://www.drugs.com/pdr/LACTASE__BETA_D_GALACTOSIDASE_.html LACTASE (BETA-D-GALACTOSIDASE) http://www-saps.plantsci.cam.ac.uk/worksheets/scotland/milk.htm “lactase (ß galactosidase)” http://www.science-projects.com/LactaseTeacher.htm “β-galactosidase is also known as lactase” http://www.science-projects.com/LacInhibSetUp.htm “lactase, or β-galactosidase.” http://www.worthington-biochem.com/BG/default.html "Beta-galactosidase (Lactase)" Now I have a flight to catch so I'll be quick and get back to you later. Look I'm sorry to tell you this but wikipedia is meant for the general public (everyone), so misconception made by laymen need to be address to correct them. Now I have no problem with fixing grammatical, spelling, technical what ever errors, go crazy, but I will not stand for not address the problem I perceive, all I ask for is a sentence or two that addresses the fact the lactase is not beta-galactosidase, that lactase is specific to a reaction and only beta-galactosidases that can hydrolyses lactose can be called “lactase”. You can rewrite it in whatever why that you find is correct as long as you state the same premise. Now if you want this described under beta-galactosidases I’m fine with that to, just say you agree and we can be done with this. Now I’m very frustrated here, I thought we could discuss this agree upon a conclusion and then edit up the solution, but you people want to edit first and tell me to now that is just rude and makes a edit war mess in the history archives.--BerserkerBen 18:14, 23 December 2005 (UTC)


 * First let me say that i DO NOT WANT to be part of any edit war. Now back to lactase. Lactase is an enzyme that has a very high substrate specificity for lactose, and even if it can hydrolyzes some other substrates, lactose is it's primary (if not only) substrate. All the lactases that we know (human, rat, rabbit, bovine, etc.) form the lactase family of enzymes. The lasctase family is a subfamily of the beta-galactosidase family of enzymes, which means that any lactase enzyme is a beta-galactosidase as well. There are beta-galactosidase enzymes, that belong to their own subfamilies, that can hydrolize lactose among other substrates but this doesn't make them lactases, it is not correct to called them lactases at all. Now if some people call these enzymes lactases too, according to the links you have provided, that is their problem. Keep in mind that there is an enzyme called beta-galactosidase (it has its own gene, it is regulated in a specific way, etc) - it is an enzyme entity or an enzyme species if you want. This enzyme is A beta-galactosidase - it belongs to the beta-galactosidase family of enzymes. (Lactase) = (a beta-galactosidase) - Yes. (Lactase) = (beta-galactosidase) - No. I guess that is where all the confusion comes. -- Boris 15:24, 28 January 2006 (UTC)
 * Misconceptions, be it "their problem" is what an encyclopedia is trying to alleviate, so it is our problem. Yes Lactase equals "a beta-galactosidase", Lactase does not equal "beta-galactosidase", I'm glad you finally recognized the source of the misconception. Now I want to dispel that misconception, I agree with you that it would be better place on the beta-galactosidase article, briefly saying something like, lactase is a subfamily of beta-galactosidase that is sometimes confused as an alternate name, etc. Now if you object why?

1. Not all β-galactosidase hydrolysis lactose, but those that can quilify as lactase enzymes. - that is uncorrect. 2. Bacterial and Archaea lactase lack a membrane binding domain and free float around the cell, these also tend to be more general beta-galactosidase that will cleave more then just lactose. - since these enzymes aren't lactases but they can hydrolyze lactose, this one should go to the "lactose" article or to their respective subfamily articles. And finaly i would like if the text in section "Industrial use" is checked, by someone who's familiar with the industrial hydrolyzis of lactose (i'm not), to make sure that the enzymes that are mentioned are true lactases and not enzymes with lactase activity - "lactase" and "enzyme that can hydrolize lactose" aren't the same thing. If any of them is a true lactase, that text can stay here, if not it should go someplace else. -- Boris 01:30, 29 January 2006 (UTC)
 * If you want to clarify for the readers that lactase is a subfamily of beta-galactosidase that is sometimes confused as an alternate name, etc., it is fine with me, whether you want to have it here in this article or in the "beta-galactosidase" article, or in both, at this point it doesn't matter to me. What i don't like is the presence of these sentences in the "Lactase" article:
 * Go right ahead and change those to your liking, none of those I have an issue with. --BerserkerBen 02:47, 29 January 2006 (UTC)

"Most humans". Hilarious.
Lactose intolerance figures can't be determined through simple genetics.

Lactose intolerance and lactase deficiency are not synonyms. Lactose intolerance is defined by the adverse symptoms that accompany a lactase deficient individual's consumption of lactose. Not all lactase deficient individuals ever have such symptoms, and thus not all lactase deficient individuals are lactose intolerant. Even if only 1/3 don't, the impressive propagandistic "75% of the world is lactose intolerant" straight-out-of-the-ass figure becomes 50%.

Lactose intolernace figures can't necessarily be determined through a simple survey or cursory diagnosis, especially in 3rd world countries.

Lactose intolerance is not the same thing as intolerance to cow milk, so any study you cite has to be able to positively differentiate them. Difficult, considering the symtoms are the same. Simple intolerance to cow milk is an allergy, totally unrelated to lactase abundance. Even if only 1/3 of those assumed to be lactose intolerant are actually intolerant to cow milk, the still passably impressive propagandistic 50% derived above becomes 33%.

If what the statistic means to say is that up to 75% of people are likely to develop lactose intolerance in their lifetimes, we have to ask what ages they are likely to develop it at. Is it really scientifically rigorous to say that a person who develops lactose intolerance on their death bed at age 84 should contribute to the statistic before that time?

Perhaps it means that up to 75% of people are at "significantly greater risk" towards contracting lactose intolerance? In which case, for the sake of perspective, please provide carcingen statistics in the same vein, so people can clearly see how utterly meaningless that really is.

Using similar vague terminology as that which is used to come up with the 75% figure, practically everyone in the world "has" cancer. --76.209.58.121 10:29, 27 February 2007 (UTC

Ummm... Most people ARE lactose intolerant. Try drinking an amount of milk proportional to what infants consume on a daily basis. Chance are pretty good you're gonna get diarrhea. Go on, try it. I dare you. What's "hilarious" is your overexcited response to a broad, generic statement. — Preceding unsigned comment added by 129.3.139.40 (talk) 03:09, 2 March 2012 (UTC)

"Approximately 65 percent of the human population has a reduced ability to digest lactose after infancy." see https://ghr.nlm.nih.gov/condition/lactose-intolerance#statistics — Preceding unsigned comment added by Jphighwater (talk • contribs) 23:32, 18 April 2016 (UTC)

In addition to the above responses which correctly reply that most human adults (and all other adult mammals) are lactose intolerant, the original comment about common cow milk intolerance being an allergy (IgE mediated) is wrong, and evinces a confusion about the mechanisms involved in allergies and lactose intolerance. — Preceding unsigned comment added by 2601:589:0:4B51:40F6:84D:6C36:E97F (talk) 19:13, 17 April 2019 (UTC)

Lactase as a dietary aid
The article does not mention lactase in pill form (such as LactAid) that can be taken with a meal. Do these pills work? That is, in the stomach does lactase survive digestion long enough to do its job? Lactase is normally used commercially to break down lactose before the food item is eaten. An explanation of this would be helpful. --Una Smith (talk) 18:54, 11 December 2007 (UTC)
 * A bit late of a response, but apparently the type of lactase used is resistant to stomach acid/enzyme degradation (Lange Gastrointestinal Physiology, 2e, Ch.15)Myoglobin (talk) 22:50, 3 May 2018 (UTC)

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Again confusing infos about EC number and CAS number.....
http://www.sigmaaldrich.com/catalog/ProductDetail.do?lang=en&N4=G3665|SIGMA&N5=SEARCH_CONCAT_PNO|BRAND_KEY&F=SPEC

http://www.sigmaaldrich.com/catalog/ProductDetail.do?lang=en&N4=G5160|SIGMA&N5=SEARCH_CONCAT_PNO|BRAND_KEY&F=SPEC

http://www.chem.qmul.ac.uk/iubmb/enzyme/EC3/2/1/108.html

http://www.genome.jp/dbget-bin/www_bget?enzyme+3.2.1.108

which one should I believe in???--124.78.211.208 (talk) 05:57, 29 July 2009 (UTC)


 * The confusion here is that there are two types of EC numbers. The number most relevant to this article is the Enzyme Commission number which is .  The second number, 232-864-1, refers to the European Commission system for coding chemicals, see EC-No. All the links that you have provided above point to the same CAS registry number . Boghog2 (talk) 04:42, 30 July 2009 (UTC)
 * Concerning food safety and EC numbers, Enzyme Commission number is not directly related to food safety, whereas the European Commission number function does relate to safety. Hence adding a what tag to an Enzyme Commission number with the justification that it has to do with food safety makes no sense. Boghog2 (talk) 05:05, 30 July 2009 (UTC)

As this is so unfinished can I make a comment. In Germany Lactase is available in tablet form and has a strength number - the usual is 9000u. This means nothing to me, whether a strength for Lactase is relevant or not i have no idea. In the UK it's a health shop product and some are printed 3000 FCC but there's no way for a consumer to understand what that means. I am very intolerant of Lactose, even the tiniest amount (from a high fat product) causes symptoms so understanding what to buy, in what strength is important. — Preceding unsigned comment added by 5.67.226.44 (talk) 09:15, 9 June 2015 (UTC)

Lactaid redirects to this page
Lactaid redirects to this page but it is not mentioned by this page. It would be useful to either provide a brief mention or restore the original page, since this seems like a notable pharmaceutical product to me. Dcoetzee 10:57, 5 July 2012 (UTC)
 * I see no need to mention any specific brand. For anyone who tries to look up any specific brand, it is entirely appropriate that it redirect here.  DrHow (talk) 20:40, 5 April 2016 (UTC)

Intro should be about stuff breaking down lactose first
The stuff about breaking down lactose should be first, not the stuff about humans. 192.12.88.228 (talk) 21:52, 23 April 2014 (UTC)

Optimum Temperature
On March 3rd 2010 the page was edited so that the optimum temperature was set to 25 degrees Celcius. I cannot find support for this claim in the referenced publications, and already asked the corresponding user who edited the article for clarification. If you find the time, please check the referenced paper and, if possible, hint me at where the temperature optimum of 25 degrees Celcius is mentioned in it. Thank you C-Otto (talk) 22:00, 9 October 2014 (UTC)


 * According to Brenda, the temperature optimum for human lactase is 20 °C, but for a mutant enzyme. The rat lactase optimum is listed at 25 while the E. coli optimum is claimed to be 37 °C.  Finally the referenced publication  didn't do a careful temperature dependence study, so their claim of 37 °C is suspect.  That is why I included the word "about".  We need a better reference.  This looks promising, but unfortunately Google books doesn't display all the pages (at least pages 84–85 are not displayed in my view) and I don't have access to a hard copy of the book. Boghog (talk) 11:58, 20 August 2015 (UTC)

lactase measuring unit
what is the lactase measuring unit 62.31.165.168 (talk) 10:36, 28 June 2023 (UTC)