Nā Hana Kemika i ke Kaʻina Hana ʻAi ʻAi
ʻO ka ʻai ʻana he moʻo o nā kaʻina hana e hoʻololi i ka meaʻai i mau molekala maʻalahi i hiki ke omo ʻia e ke kino a hoʻohana ʻia ma ke ʻano he kumu ikehu, nā poloka kūkulu, a me ka hoʻoponopono ʻana i nā hana physiological like ʻole. Ma hope o nā kaʻina hana "mechanical" e like me ka nau ʻana a me ka wili ʻana i ka meaʻai i loko o ka ʻōpū, aia nā hopena kemika paʻakikī loa. Pili kēia mau hopena i nā enzymes, nā waikawa, nā kumu, a me nā hui olaola like ʻole e hana ana i loko o nā kūlana pH kikoʻī. ʻO ka hoʻomaopopo ʻana i nā hopena kemika i komo i ka ʻai ʻana e kōkua iā mākou e hoʻomaopopo i ke kumu e hoʻopilikia nui ai ke ʻano o ka meaʻai, ke ʻano o kā mākou ʻai ʻana, a me ke olakino o kā mākou mau ʻōpū ʻai i ka omo ʻana i nā meaʻai.
1. Hoʻomaka ka ʻai ʻana ma ka waha: ka hydrolysis mua o nā kalapona
ʻO ka waha ke kahua mua o ka ʻeli ʻana o nā kemika. Ke nau ʻia ka meaʻai, hana nā kelepa salivary i ka saliva e loaʻa ana ka enzyme salivary amylase (ptyalin). Hoʻopau ʻo Amylase i nā kalapona paʻakikī e like me ka starch i loko o nā mole liʻiliʻi, ʻo ka maltose a me nā oligosaccharides ka mea nui.
Ma ke ʻano kemika, he hopena hydrolysis kēia kaʻina hana, ʻo ia hoʻi ka uhaki ʻana i nā pilina kemika me ka hoʻohana ʻana i ka wai me ke kōkua o nā enzymes ma ke ʻano he catalysts. Hoʻopau mālie ʻia nā pilina glycosidic i loko o nā polysaccharides, e hopena ana i nā molekala pōkole. Eia nō naʻe, he pōkole ka hoʻoheheʻe ʻana o ka carbohydrate i loko o ka waha no ka mea e hele koke ana ka meaʻai i loko o ka ʻōpū, kahi e hoʻopau ai nā kūlana waikawa kiʻekiʻe i ka salivary amylase.
Loaʻa pū i ka luwa ka bicarbonate a me nā protein pale like ʻole e kōkua i ka mālama ʻana i ka pH o ka waha i ʻole e lilo i waikawa loa, e ʻae ana i nā enzymes e hana pono. Hoʻonui ka nau ʻana i ka ʻili o ka meaʻai, e wikiwiki ana i nā hopena kemika ma hope no ka mea he maʻalahi ke komo ʻana o nā enzymes i nā substrates.
2. ʻŌpū: nā hopena i nā kūlana waikawa a me ka denaturation protein
I loko o ka ʻōpū, ua hoʻomalu ʻia ka ʻeli ʻana o nā kemika e nā waikawa a me nā enzymes. Hoʻopuka ka paia o ka ʻōpū i ka waikawa hydrochloric (HCl), e mālama ana i ka pH o ka ʻōpū i haʻahaʻa loa (ma kahi o 1,5–3). He nui nā hana kemika koʻikoʻi o kēia wahi waikawa.
ʻO ka mea mua, ʻo HCl ke kumu o ka denaturation protein. ʻAʻole pili ka denaturation i ka wāwahi ʻana i nā protein i nā waikawa amino, akā, e hoʻololi ana i ke ʻano ʻekolu-dimensional o ka protein, e wehe ai nā kaulahao. ʻO kēia ʻano "wehe" e maʻalahi ai i nā enzymes ke ʻoki i nā pilina peptide i ka hana aʻe.
ʻO ka lua, hoʻoulu ke kaiapuni waikawa i ka enzyme pepsin. Hoʻopuka mua ʻia kēia enzyme ma ke ʻano hana ʻole, ʻo pepsinogen, e pale i ka ʻōpū mai ka "ʻeli ʻana" iā ia iho. Hoʻololi ʻo HCl i ka pepsinogen i pepsin ma o ke kaʻina hana e pili ana i ka uhaki ʻana i nā ʻāpana kikoʻī o ka molekole pepsinogen. A laila hoʻoikaika ʻo Pepsin i ka hydrolysis o nā pilina peptide i loko o nā protein, e hana ana i nā peptides pōkole.
ʻO ke kolu, kōkua ʻo HCl i ka pepehi ʻana i nā microorganism he nui e komo i loko o ke kino me ka meaʻai. No laila, ma waho aʻe o kāna hana hoʻoheheʻe, hana pū ia i kahi "reaksi kemika" e hana ana ma ke ʻano he ʻano pale no ke kino.
3. Ke kuleana o ka bile: ka emulsification momona ma ke ʻano he kaʻina hana kino-kemika
Ma hope o ka haʻalele ʻana i ka ʻōpū, komo ka meaʻai (chyme) i ka ʻāpana mua o ka ʻōpū liʻiliʻi, ʻo ia hoʻi ka duodenum. Maanei, ʻoi aku ka ʻokoʻa o nā hopena kemika o ka ʻai ʻana, e pili ana i nā wai mai ka pancreas a me ka bile mai ke akepaʻa.
Aia i loko o ka bile nā paʻakai bile e kōkua ana i ka emulsification o nā momona. Manaʻo pinepine ʻia ka emulsification he hana kino, akā he hana kino-kemika maoli ia: he hopena wai-soluble (hydrophilic) ko nā paʻakai bile a me kahi hopena momona-soluble (hydrophobic). Hoʻohaʻahaʻa kēia ʻano i ka ʻili a wāwahi i nā globules momona nui i nā kulu liʻiliʻi.
ʻAʻole ka emulsification he hopena haki pili kemika, akā he mea nui ia no ka hoʻonui ʻana i ka ʻili o ka momona i hiki ai i ka enzyme haki momona, ʻo lipase, ke hana maikaʻi. Me ka ʻole o ka emulsification, e lohi loa ka ʻeli ʻana o ka momona no ka mea ʻaʻole hui maʻalahi ka momona me nā wai ʻeli wai.
4. Pancreas: kikowaena o nā enzymes a me nā hopena neutralization acid
Hoʻopuka ka pancreas i ka wai pancreatic e loaʻa ana ka bicarbonate (HCO₃⁻) a me nā ʻenzyme like ʻole. Hana ka Bicarbonate i kahi hopena neutralization: hoʻopau ʻia ka chyme acidic loa mai ka ʻōpū e hoʻolilo i ka pH i loko o ka ʻōpū liʻiliʻi i ʻoi aku ka alkaline (ma kahi o 6-8). Hiki ke hoʻomaopopo maʻalahi ʻia ka hopena kemika ma ke ʻano he pilina o nā ions H⁺ (ʻakika) me ka bicarbonate e hana i ka waikawa carbonic, a laila e palaho i loko o ka wai a me ke kalapona dioxide. He mea nui kēia neutralization no ka mea he nui nā enzymes intestinal e hana pono ana ma kahi pH neutral a alkaline iki.
Ma waho aʻe o ka bicarbonate, hana ka pancreas i nā enzymes:
– ʻO ka pancreatic amylase, hoʻomau i ka hydrolysis o nā kalapona i loko o nā disaccharides a me nā oligosaccharides.
– Hoʻopau ʻo Trypsin a me chymotrypsin i nā protein/peptides i nā peptides liʻiliʻi. Hana ʻia nā mea ʻelua ma nā ʻano hana ʻole (trypsinogen a me chymotrypsinogen) a hoʻāla ʻia i loko o ka ʻōpū e pale aku i ka pancreas mai ka hōʻino ʻia e kāna mau enzymes ponoʻī.
– ʻO ka lipase pancreatic, hydrolyzes nā triglycerides i nā waikawa momona a me nā monoglycerides (a i ʻole glycerol a me nā waikawa momona ma muli o ke kahua).
– ʻO Nuclease, hoʻokaʻawale i nā waikawa nucleic (DNA/RNA) i loko o nā nucleotides.
Hoʻomalu ʻia kēia kaʻina holoʻokoʻa e nā hopena hydrolysis i hoʻolalelale ʻia e ka enzyme. He kikoʻī nā enzymes: hoʻokahi ʻano enzyme e uhaʻi wale i kekahi mau pilina i loko o kahi substrate kikoʻī, e ʻae ana i ka hoʻoheheʻe ʻana e hoʻomau i kahi ʻano i kuhikuhi ʻia a me ka maikaʻi.
5. ʻōpū liʻiliʻi: ka ʻeli hope loa a me ke kūkulu ʻia ʻana o nā molekala i mākaukau no ka omo ʻana
Hoʻopuka nā paia o ka ʻōpū liʻiliʻi i nā enzymes "brush border" (nā enzymes villi surface) e hoʻopau i ka ʻeli ʻana i loko o kahi ʻano hiki ke omo ʻia.
No nā kalapona:
– Hoʻopau ʻo Maltase i ka maltose i ʻelua mau mole glucose.
– Hoʻopau ka Sucrase i ka sucrose i loko o ka glucose a me ka fructose.
– Hoʻopau ka Lactase i ka lactose i loko o ka glucose a me ka galactose.
ʻO kēia mau mea a pau he mau hopena hydrolysis o nā disaccharides i loko o nā monosaccharides, kahi ʻano e hiki ke komo i loko o ke kahe koko ma o nā pūnaewele epithelial intestinal.
No ka protein:
– Hoʻopau nā enzymes peptidase i nā peptides liʻiliʻi i nā waikawa amino. ʻO ka ʻoki ʻana i ka pilina peptide ka hydrolysis hou aʻe i nā ʻāpana liʻiliʻi loa e hiki ai i ke kino ke hoʻohana e kūkulu i nā ʻiʻo hou, nā hormones, a me nā enzymes.
No ka momona:
– Hoʻokumu nā huahana o ka ʻeli ʻana o ka momona (nā waikawa momona, monoglycerides) i nā micelles me nā paʻakai bile, a laila komo i loko o nā pūnaewele ʻōpū. I loko o nā pūnaewele, hiki ke hoʻohui hou ʻia nā ʻāpana momona i loko o nā triglycerides a hoʻopaʻa ʻia i loko o nā chylomicrons e komo i loko o nā kīʻaha lymphatic.
6. ʻōpū nui: ka hoʻoulu ʻana o nā microbes a me nā hopena kemika hou aʻe
ʻOiai ʻo ka hapa nui o ka omo ʻana o nā meaʻai i loko o ka ʻōpū liʻiliʻi, pili pū ka ʻōpū nui i nā hopena kemika, ʻo ia hoʻi ma o ka hana a nā bacteria o ka ʻōpū. Hoʻoulu ka bacteria i ka fiber i ʻeli ʻole ʻia, e hana ana i nā waikawa momona kaulahao pōkole e like me ka acetate, propionate, a me ka butyrate. Hiki ke omo ʻia kēia mau hui a hoʻohana ʻia ma ke ʻano he kumu ikehu a pāʻani i kahi kuleana i ke olakino o ka paia o ka ʻōpū.
Ma waho aʻe o ka fermentation, hoʻopili ka ʻōpū nui i ka wai a me nā electrolytes, e kōkua ana i ka hoʻokumu ʻia ʻana o nā feces. Hōʻike kēia kaʻina hana ʻaʻole wale ka wāwahi ʻana i ka meaʻai, akā, ʻo ka hoʻoponopono ʻana hoʻi i ke kaulike wai o ke kino.
7. Nā mea e hoʻohuli ai i nā hopena kemika i ka ʻai ʻana
Hoʻopili ʻia ka pono o nā hopena kemika digestive e kekahi mau kumu:
1. pH: Loaʻa i nā enzymes kahi pH kūpono loa. Hana maikaʻi ʻo Pepsin i nā kūlana acidic, ʻoiai ʻo nā enzymes pancreatic e hana maʻamau i nā kūlana neutral-alkaline.
2. Mahana: ʻO ka mahana o ke kino (ma kahi o 37°C) he mea kūpono ia no nā enzymes kanaka. Hiki i ke kuni kiʻekiʻe a i ʻole nā kūlana koʻikoʻi ke hoʻopilikia i ka hana enzyme.
3. Loaʻa ʻana o nā enzymes a me nā substrates: ʻO ka nele o kekahi mau enzymes (e.g. lactase) ke kumu o nā maʻi ʻōpū e like me ka lactose intolerance.
4. Ka wikiwiki o ka hoʻokahe ʻana o ka ʻōpū a me ka neʻe ʻana o ka ʻōpū: ʻO ka wikiwiki a lohi paha e hiki ke hoʻololi i ka manawa pili o nā enzymes me ka meaʻai.
5. Ola kino hoʻoheheʻe: ʻO ka mumū, nā maʻi ate/pancreas, a i ʻole nā maʻi ʻōpū hiki ke hōʻemi i ka hana ʻana o ka enzyme a hoʻololi paha i ke kaiapuni kemika.
Pani
ʻO nā hopena kemika i komo i ka ʻai ʻana he pilina paʻakikī o nā enzymes, nā waikawa, nā kumu, a me nā hui olaola ʻē aʻe e hana ʻia ana mai ka waha a i ka ʻōpū nui. ʻO ka hydrolysis o nā kalapona, nā protein, a me nā momona e hōʻoiaʻiʻo ana ua hoʻololi ʻia ka meaʻai i nā molekala maʻalahi e like me ka glucose, nā waikawa amino, a me nā waikawa momona e hiki ai i ke kino ke omo. ʻO ka neutralization o nā waikawa e ka bicarbonate, ka emulsification o nā momona e ka bile, a me ka fermentation microbial i loko o ka ʻōpū nui e hōʻike ana ʻaʻole wale ka ʻai ʻana e pili ana i ka "wāwahi ʻana i ka meaʻai," akā e pili ana hoʻi i ka hoʻokumu ʻana i nā kūlana kemika kūpono no ka hoʻohana pono ʻana i nā meaʻai. Ma ka hoʻomaopopo ʻana i kēia kaʻina hana, hiki iā mākou ke hana i nā koho meaʻai naʻauao a mālama i kahi ʻōnaehana ʻai olakino no ka omo pono ʻana i nā meaʻai.
