Likarabelo tsa Lik'hemik'hale tse Etsahalang Nakong ea Tšilo ea Lijo
Tšilo ea lijo ke letoto la lits'ebetso tse fetolang lijo hore e be limolek'hule tse bonolo e le hore li ka monngoa ke 'mele le ho sebelisoa e le mehloli ea matla, li-block tsa kaho, le ho laola mesebetsi e fapaneng ea 'mele. Ts'ebetso ena ha e akarelletse feela metsamao ea mechine e kang ho hlafuna le ho hema ka thata, empa hape le liketso tsa lik'hemik'hale tse laoloang ke li-enzyme, li-acid le maro a mang a tšilo ea lijo. Litšoaneleho tsena tsa lik'hemik'hale li etsahala ka mekhahlelo ho tloha molomong ho ea mala a manyane, ebe li phethoa ka thuso ea likokoana-hloko tse ka maleng a maholo. Se latelang ke tlhaloso ea liketso tse kholo tsa lik'hemik'hale tse hlahang tšilong ea lijo ea motho.
1. Tšilo ea lijo ka Molomong: Hydrolysis ea Khabohaedreite ea Pele
Ts'ebetso ea tšilo ea lijo e qala ka hanong ka ho siloa ha meno ka mechine le ho siloa ha lik'hemik'hale ka mathe. Mathe a na le enzyme ea salivary amylase (ptyalin), e qhaqhang lik'habohaedreite tse rarahaneng, haholo-holo starch, hore e be limolek'hule tse bonolo.
Karabelo e ka sehloohong ka hanong ke hydrolysis (ho senyeha ka ho eketsa metsi). Ha re e beha ka bokhutšoanyane, amylase e roba litlamo tsa glycosidic ho starch, e hlahisa maltose le dextrin (liketane tse kgutshwane tsa tsoekere). Karabelo ena e etsahala hantle ka pH e batlang e sa nke lehlakore (hoo e ka bang 6,8–7,2). Mathe a boetse a na le palo e nyane ea lipase ea lingual, e qalang ho sebetsa mafura, empa monehelo oa eona o monyane nakong ena.
Ho sa le jwalo, bolus e kolobisitsweng le e bopilweng ya dijo e a metswa mme e tsamaiswa ka hara mothapo. Ha ho na diphetoho tse ikgethang tsa dikhemikhale tse hlahang ka hara mothapo, empa bolus e tsamaiswa ke metsamao ya peristaltic ho ya mpeng.
2. Tšilo ea lijo ka mpeng: Ho senyeha ha protheine le ho qhibilihisoa ha metsi ha pele
Ka mpeng, diketso tsa dikhemikhale tsa tshilo ya dijo di etsahala tikolohong e nang le asiti e ngata ka lebaka la boteng ba hydrochloric acid (HCl). HCl e na le mesebetsi e mmalwa ya bohlokwa: ho theola pH ya mpa (hoo e ka bang 1,5–3,5), ho bolaya dikokwana-hloko tse ding, le ho fetola sebopeho sa diprotheine tse nang le mahlakore a mararo ho etsa hore di silehe habonolo ke dienzyme.
Enzyme e ka sehloohong ka mpeng ke pepsin, e kenngwang tshebetsong ho tloha sebopehong sa yona se sa sebetseng, pepsinogen, ke HCl. Pepsin e pshatla diprotheine ka dikotwana tse nyane, tse bitswang di-peptide. Karabelo ha se ho "tjhesa" kapa ho oxidation, empa ke hydrolysis ya dibopeho tsa peptide ka hara diprotheine. Tshebetso ena e fetola diprotheine tse rarahaneng hore e be di-polypeptide tse kgutshwane, e leng se thusang ho sila dijo ho eketsehileng ka maleng.
Ntle le pepsin, mpa e boetse e hlahisa lipase ea mpa, e thusang ho hydrolysis ea mafura, haholo-holo ho masea a jang mafura a mangata a tsoang lebeseng. Leha ho le joalo, tšilo ea mafura ea mantlha e etsahala ka maleng a manyane. Mpa e boetse e hlahisa mucus ho sireletsa lera la mpa liphellong tse senyang tsa HCl le ts'ebetso ea enzyme.
3. Karolo ea Sebete le Sefuba sa Nyooko: Ho Emulsification ea Mafura
Lijo tse se nang metsi a mangata tse tsoang mpeng (chyme) li kena ka har'a duodenum (mala a manyane). Mona, tšilo ea mafura e nolofalloa ke bile, e hlahisoang ke sebete 'me e bolokoa ka har'a gallbladder. Bile ha se enzyme, empa e na le letsoai la bile le thusang ho qhaqha li-globule tse kholo tsa mafura hore e be marotholi a manyane ka mokhoa o bitsoang emulsification.
Emulsification ha se karabelo ea lik'hemik'hale e robang litlamo, empa ke ts'ebetso ea 'mele-khemikhale e eketsang sebaka sa mafura, e lumellang li-enzyme tsa lipase ho sebetsa ka katleho. Matsoai a bile a amphipathic: lehlakore le leng le "rata metsi" 'me le leng le "rata mafura," kahoo a ka tsitsisa marotholi a mafura tikolohong ea metsi ea mala.
4. Tšilo ea lijo ka maleng a manyane: Hydrolysis e matla ka li-enzyme tsa Pancreatic le li-enzyme tsa mala
Mala a manyane ke sebaka sa mantlha sa tšilo ea lik'hemik'hale le ho monngoa ha lihlahisoa tsa tšilo ea lijo. Mehloli e 'meli e meholo ea li-enzyme mona ke manyeme le lebota la mala a manyane.
a) Lik'habohaedreite: Ho tloha ho Poly- le Disaccharides ho ea ho Monosaccharides
Lero la pancreatic le na le pancreatic amylase, e tswelang pele ho senyeha ha starch ho ba maltose, maltotriose, le dextrin. Ka mor'a moo, dienzyme tse hodima intestinal villi (dienzyme tse moeding wa borashe) di fetola di-disaccharide hore e be di-monosaccharide:
– Maltase: maltose → tsoekere + tsoekere
– Sucrase: sucrose → tsoekere + fructose
– Lactase: lactose → glucose + galactose
Ena ke karabelo ea hydrolysis e hlahisang li-monosaccharide ka mokhoa o ka monngoang maling. Tsoekere le galactose li monngoa ka ho tsamaisoa ha bobeli ka mafolofolo, ha fructose ka ho hasana ho nolofalitsoeng.
b) Protheine: Ho tloha ho Li-polypeptide ho ea ho Li-amino acid
Lekhopho le ntša mefuta e sa sebetseng ea li-enzyme tsa protease, tse kang trypsinogen le chymotrypsinogen. Li-enzyme tsena li kenngoa tšebetsong ka har'a duodenum ke enterokinase le ketane ea karabelo. Hang ha e kentsoe tšebetsong:
– Trypsin le chymotrypsin li arola li-polypeptide hore e be li-peptide tse nyane.
– Carboxypeptidase e khaola li-amino acid ho tloha pheletsong ea ketane ea peptide.
Holim'a mala, ho na le li-aminopeptidase le li-dipeptidase tse phethelang ho aroloa ha li-amino acid (hammoho le karolo e nyane ea li-dipeptide le li-tripeptides tse ka boelang tsa monngoa le ho qhaqhoa liseleng).
c) Mafura: Ho tloha ho Triglycerides ho ea ho Mafura a Li-acid le Monoglycerides
Lebese le boetse le hlahisa pancreatic lipase e sebetsang hantle haholo, haholo-holo ka mor'a hore mafura a emulsisoe ke letsoai la bile. Lipase e qhaqha triglycerides ka hydrolysis:
– triglycerides → monoglycerides + mafura a mahala
Mafura a hlahang a bopa di-micelles, e leng "dipakete" tse nyane tseo matswai a bile a thusang ho di kgomaretsa hodima disele tsa mala. Ka hare ho disele tsa mala, mafura a hlophiswa botjha hore e be di-triglyceride mme a kenngwa ka di-chylomicron bakeng sa ho iswa tsamaisong ya lymphatic.
5. Tšilo ea lijo ka maleng a maholo: Ho belisoa ke likokoana-hloko
Ka maleng a maholo, boholo ba diketso tsa dikhemikhale ha di etswe ke dienzyme tsa batho, empa ke microbiota ya mala. Faeba ya dijo (cellulose, hemicellulose, pectin) e ke keng ya silwa ka maleng a manyane e bediswa ho ba di-fatty acid tse kgutshwane (SCFAs) tse kang acetate, propionate, le butyrate. Dihlahiswa tsena di thusa bophelo bo botle ba mala mme di ka monngwa e le mohlodi o eketsehileng wa matla.
Likokoana-hloko li boetse li hlahisa likhase tse kang carbon dioxide, methane le haeterojene e le lihlahisoa tsa ho belisoa. Ho feta moo, microbiota e phetha karolo ea ho qaptjoa ha livithamine tse itseng, tse kang vithamine K le livithamine tse ling tsa B, leha monehelo oa tsona o fapana ho ea ka motho.
6. Taolo ea Likarabelo tsa Lik'hemik'hale: Lihormone le pH
Ho netefatsa hore diketso tsena tsohle tsa dikhemikhale di tswela pele hantle, mmele o laola tshilo ya dijo ka tsamaiso ya methapo le dihormone. Dihormone tse pedi tsa bohlokwa ke:
– Secretin: e hlohlelletsa manyeme ho ntsha bicarbonate ho thibela asiti e tswang ka mpeng ka hara duodenum, e le hore pH e be e loketseng mosebetsi wa dienzyme tsa mala le manyeme.
– Cholecystokinin (CCK): e hlohlelletsa manyeme ho lokolla dienzyme tsa tshilo ya dijo mme e etsa hore gallbladder e honyele ho lokolla bile.
pH le yona e bohlokwa. Dienzyme di sebetsa ka hara tekanyo e itseng ya pH: pepsin e sebetsa hantle tikolohong e nang le asiti ka mpeng, ha dienzyme tsa pancreatic le mala di sebetsa hantle ka pH e sa nke lehlakore ho isa ho e nang le alkaline hanyane ya mala a manyane.
Ho koala
Likarabelo tsa lik'hemik'hale tsa tšilo ea lijo ke motsoako oa hydrolysis ke li-enzyme, denaturation ke li-acid, emulsification ea mafura ke bile, le belisoa ke likokoana-hloko tsa mala. Mekhoa ena kaofela e tlatsana ho fetola lik'habohaedreite hore e be li-monosaccharides, liprotheine hore e be li-amino acid, le mafura hore e be li-fatty acid le li-monoglycerides bakeng sa ho monngoa ke 'mele. Ho utloisisa liketso tsa lik'hemik'hale tsa tšilo ea lijo ho re thusa ho ananela bohlokoa ba li-enzyme, maemo a pH, le bophelo bo botle ba tšilo ea lijo ho tšehetsa ho monngoa ha limatlafatsi le ho boloka botsitso ba 'mele ka kakaretso.
