Õèìèÿ: Îáì³í âóãëåâîä³â, Ó÷åáíîå ïîñîáèå

  • Êàòåãîðèÿ: Õèìèÿ
  • Òèï: Ó÷åáíîå ïîñîáèå

Ïëàí

1. Ôåðìåíòàòèâíå ïåðåòâîðåííÿ âóãëåâîä³â ó õàð÷îâîìó òðàêò³ ëþäèíè

2. Ïîøèðåííÿ âóãëåâîä³â ó îðãàí³çì³ ëþäèíè

3. Ïðîöåñè ïåðåòâîðåííÿ âóãëåâîä³â íà êë³òèííîìó ð³âí³:

3.1. Ñèíòåç ãë³êîãåíó ç ãëþêîçè (ãë³êîãåíåç)

3.2. Ðîçïàä ãë³êîãåíó äî ãëþêîçè (ãë³êîãåíîë³ç)

3.3. Ãë³êîë³ç (àíàåðîáíèé ðîçïàä)

3.4. Äèõàííÿ (àåðîáíèé ðîçïàä âóãëåâîä³â)

4. Åíåðãåòè÷í³ åôåêòè ïðîöåñ³â


Âóãëåâîäè ñêëàäàþòü á³ëÿ 70 % õàð÷îâîãî ðàö³îíó ëþäèíè (áîðîøíî, êðóïè, êàðòîïëÿ – êðîõìàëåâì³ñí³; ìåä, ÿãîäè, ôðóêòè – ì³ñòÿòü ñàõàðîçó, ãëþêîçó ³ ôðóêòîçó), ÿâëÿþ÷èñü îñíîâíèì äæåðåëîì åíåð㳿 äëÿ îðãàí³çìó. Ïîøèðåíèé ó ïðèðîä³ ïîë³ñàõàðèä êë³òêîâèíà ò³ëüêè ÷àñòêîâî çàñâîþºòüñÿ îðãàí³çìîì ëþäèíè çà äîïîìîãîþ áàêòåð³é òîâñòîãî êèøå÷íèêà. Îñíîâíîþ ôóíêö³ºþ êë³òêîâèíè º çàáåçïå÷åííÿ ïåðèñòàëüòèêè õàð÷îâîãî òðàêòó, ñòèìóëþâàííÿ ñåêðåòîðíî¿ ä³ÿëüíîñò³, ñïðèÿííÿ ñèíòåçó â³òàì³íó Ê çà äîïîìîãîþ êèøå÷íî¿ ì³êðîôëîðè.

Ïîñê³ëüêè âóãëåâîäè çàñâîþþòüñÿ ó âèãëÿä³ ìîíîöóêðèä³â, òî ñêëàäí³ âóãëåâîäè (äèöóêðèäè, ïîë³öóêðèäè) ïîâèíí³ ïîïåðåäíüî ðîçùåïèòèñÿ. óäðîë³òè÷íå ðîçùåïëåííÿ ïðîõîäèòü ï³ä âïëèâîì ôåðìåíò³â ùî íîñÿòü çàãàëüíó íàçâó ãë³êîçèäàçè. Îïòèìóì 䳿 ãë³êîçèäàç ëåæèòü â íåéòðàëüíîìó òà ñëàáêîëóæíîìó ñåðåäîâèù³ (âèêëþ÷åííÿ àì³ëàçà ñëèíè – ñëàáêîêèñëå), ùî ³ îáóìîâëþº ïåâíó ëîêàë³çàö³þ ïðîöåñ³â ðîçùåïëåííÿ ó õàð÷îâîìó òðàêò³ ëþäèíè.

³ää³ë

òðàâëåííÿ

Îïòèìóì 䳿 ôåð-ìåíòíèõ ñèñòåì (ðÍ) Ïðîöåñè Ôåðìåíòè
Ðîòîâà ïîðîæíèíà 6.5–7.0 Ðîçùåïëåííÿ êðîõìàëþ äî äåêñòðèí³â, ÷àñòêîâî ìàëüòîçè äî ãëþêîçè ³ ôðóêòîçè. àì³ëàçà ñëèíè, ìàëüòàçà.
Ñòðàâîõ³ä 7 Ïðîöåñè ðîçùåïëåííÿ â³äñóòí³ ó çâ‘ÿçêó ç øâèäêèì ïðîõîäæåííÿì ñóáñòðàò³â.
Øëóíîê 1–2 Ïðîöåñè ðîçùåïëåííÿ â³äñóòí³ ó çâ‘ÿçêó ç ³íàêòèâàö³ºþ ôåðìåíò³â «êèñëèì» ñåðåäîâèùåì.
12–ïàëà êèøêà 7.0–7.5 Îñòàòî÷íå ðîçùåïëåííÿ äåêñòðèí³â äî äèñàõàðè-ä³â.

ôåðìåíòè ï³äøëóíêîâî¿ çàëîçè: ê³íöåâà äåêñòðèíàçà, –àì³ëàçà, ìàëüòàçà, ñàõàðàçà, ëàêòà-çà.

Òîíêèé êèøå÷íèê 7.0–7.5 Ðîçùåïëåííÿ äèñàõàðèä³â äî ìîíîñàõàðèä³â. Ïîñòó-ïàííÿ ìîíîñàõàðèä³â ó êðîâ.

ʳíöåâà äåêñòðèíàçà, –àì³ëàçà, ìàëüòàçà, ñàõàðàçà, ëàêòà-çà.

Òîâñòèé êèøå÷íèê

Ðîçùåïëåííÿ êë³òêîâèíè äî öåëîá³îçè ³ ãëþêîçè. Ñèíòåç â³òàì³íó Ê. Ïðîõî-äÿòü ïðîöåñè çáðîäæåííÿ âóãëåâîäíåâèõ çàëèøê³â ç âèä³ëåííÿì ÑÎ2, Í2, ÑÍ4. Ôîðìóâàííÿ êàëîâèõ ìàñ.

Öåëþëàçà, ôåðìåíòí³ ñèñòåìè áàêòåð³é.

 òîíêîìó êèøå÷íèêó â³äáóâàþòüñÿ ïðîöåñè âñìîêòóâàííÿ ìîíîñàõàðèä³â ÷åðåç ñèñòåìó ìåìáðàí ó êðîâ‘ÿíå ðóñëî. Äëÿ ïðîöåñó âñìîêòóâàííÿ õàðàêòåðíî: çíà÷-í³ åíåðãåòè÷í³ âèòðàòè îðãàí³çìó (àêòèâíèé ô³ç³îëîã³÷íèé ïðîöåñ); ³çîìåðèçàö³ÿ (òðàíñôîðìàö³ÿ, ïåðåòâîðåííÿ) ñóì³ø³ ïðîñòèõ âóãëåâîä³â (98 %) ó ãëþêîçó; òðàíñïîðòóâàííÿ ãëþêîçè ÷åðåç ìåìáðàíè ó ôîðì³ ãëþêîçî-ôîñôàòó (íàâ³äü ïðîòè çíà÷åíü ¿¿ êîíöåíòðàö³¿ ó êðîâ‘ÿíîìó ðóñë³).

Ç òîêîì êðîâ³ ìîíîöóêðèäè ÷åðåç âîðîòíó âåíó ïîòðàïëÿþòü ó ïå÷³íêó, äå âèêî-ðèñòîâóþòüñÿ äëÿ á³îñèíòåçó ãë³êîãåíó (3–5 %), á³îñèíòåçó æèð³â (30–35 %), îêèñëþþòüñÿ äî âóãëåêèñëîãî ãàçó ³ âîäè (60–70 %). Ïåâíà, ô³ç³îëîã³÷íî íîðìàëüíà ê³ëüê³ñòü ãëþêîçè (120 ìã íà 100 ñì3), º íåâ³ä‘ºìíîþ ñêëàäîâîþ êðîâ³, çàáåçïå÷óþ÷è ãîìåîñòàç îðãàí³çìó. Âîíà íåîáõ³äíà äëÿ íîðìàëüíîãî ôóíêö³îíó-âàííÿ ãîëîâíîãî ìîçêó, ì‘ÿç³â ñåðöÿ, íåðâîâî¿ òêàíèíè (ãëþêîçà –ãîëîâíå äæåðå-ëî åíåð㳿).

Ïðè ï³äâèùåí³é êîíöåíòðàö³¿ ãëþêîçè â êðîâ³ (á³ëüøå 140 ìã) ãîâîðÿòü ïðî ã³ïåðãë³êåì³þ. Âèêëèêàºòüñÿ âæèâàííÿì ïðîäóêò³â áàãàòèõ íà âóãëåâîäè (àë³ìåíòàðíà ã³ïåðãë³êåì³ÿ); íåäîñòàòí³ì ñèíòåçîì ³íñóë³íó (öóêðîâèé ä³àáåò); ïîíàä-íîðìîâèì ñèíòåçîì àäðåíàë³íó ³ ãëþêàãîíó. Ñòàí ã³ïåðãë³êå쳿 ïðèâîäèòü äî îæèð³ííÿ.

Ïðè ïîíèæåí³é êîíöåíòðàö³¿ ãëþêîçè â êðîâ³ (ìåíøå 120 ìã) ãîâîðÿòü ïðî ã³ïîãë³êåì³þ. Âèêëèêàºòüñÿ òðèâàëèì ãîëîäóâàííÿì; âåëèêèìè ô³çè÷íèìè íàâàíòàæåííÿìè; íåäîñòàòí³ì ñèíòåçîì ãëþêàãîíó ³ àäðåíàë³íó; ïîíàäíîðìîâèì ñèíòåçîì ³íñóë³íó. Ïðèâîäèòü äî äåñòðóêòèâíèõ çì³í â ãîëîâíîìó ìîçêó, íåðâîâ³é òêàíèí³, íèðêàõ. Ñòàí òðèâàëî¿ ã³ïîãë³êå쳿 ïðèâîäèòü äî âèñíàæåííÿ îðãàí³çìó ³ ñìåðò³.

Îòæå:

Îñíîâíà ðîëü â ïðîöåñàõ îáì³íó âóãëåâîä³â íàëåæèòü ïå÷³íö³, ä³ÿëüí³ñòü ÿêî¿ ðåãóëþºòüñÿ íåðâîâîþ ³ åíäîêðèííîþ ñèñòåìàìè (³íñóë³í, àäðåíàë³í–ãëþêàãîí).

Ó âèïàäêó ïîâíîãî åíåðãåòè÷íîãî çàáåçïå÷åííÿ îðãàí³çìó, ç íàäëèøêó ãëþêîçè ñèíòåçóºòüñÿ ãë³êîãåí. Ïðîöåñè ãë³êîãåíåçó ïðîõîäÿòü â êë³òèíàõ ð³çíèõ îðãàí³â ³ òêàíèí, àëå íàéá³ëüøó çäàòí³ñòü äî íàêîïè÷åííÿ ìàþòü êë³òèíè ïå÷³íêè. Ãë³êîãåí ïå÷³íêè º îñíîâíèì ðåçåðâíèì äæåðåëîì âóãëåâîä³â äëÿ îðãàí³çìó.


3. Ïðîöåñè ïåðåòâîðåííÿ âóãëåâîä³â íà êë³òèííîìó ð³âí³

 

3.1 Ãë³êîãåíåç (ñèíòåç ãë³êîãåíó ç ãëþêîçè)

1. Ãëþêîçà, ÿêà ç òîêîì êðîâ³ íàäõîäèòü ó ïå÷³íêó àêòèâóºòüñÿ çà äîïîìîãîþ ôåðìåíòó ãåêñîê³íàçè ³ ÀÒÔ, ïåðåòâîðþþ÷èñü â ãëþêîçî-6-ôîñôàò:

                                                                                                HO    OH

                   CH2OH                                                       CH2O–P=O                  

H                H                H      ÀÒÔ ÀÄÔ H      H               H

                                                                                                                  

OH    OH    H      OH                                OH    OH   H OH

                   H       OH                                         H               OH

                   Ãëþêîçà                                                     Ãëþêîçî–6–ôîñôàò

2. Ãëþêîçî-6-ôîñôàò ï³ä 䳺þ ôîñôîãëþêîìóòàçè ïåðåòâîðþºòüñÿ íà ãëþêîçî-1-ôîñôàò:

                    HO   OH

                   CH2O–P=O                                                 CH2OH

 H               H                H                                   H      H               H

                                                ôîñôîãëþêîìóòàçà                                             OH

OH    OH    H      OH                                OH    OH   H O–P=O

                   H       OH                                         H               OH    OH

                   Ãëþêîçî–6–ôîñôàò                                   Ãëþêîçî–1–ôîñôàò

3. Ãëþêîçî-1-ôîñôàò ïîâòîðíî àêòèâóºòüñÿ ÓÒÔ (óðèäèíòðèôîñôàòîì) ç âèêî-ðèñòàííÿì åíåð㳿 äâîõ ìàêðîåðã³÷íèõ çâ‘ÿçê³â, óòâîðþþ÷è àêòèâîâàíó óðè-äèí-äèôîñôàòãëþêîçó.

ÓÐÈÄÈÍ

                   CH2OH                                                       CH2OH                OH    O

H                H                H                                   H      H               H               P

                                                OH    ÓÒÔ  Í4Ð2Î7                                     O      

OH    OH    H      O–P=O                         OH    OH   H O–P=O

                   H       OH   OH                                 H               OH    OH

                   Ãëþêîçî–1–ôîñôàò                                             ÓÄÔ–ãëþêîçà

4. Ïîñê³ëüêè ñèíòåç ãë³êîãåíó ïðîõîäèòü «çàòðàâî÷íèì» ìåòîäîì (ó ðîë³ çàòðàâêè âèêîðèñòîâóºòüñÿ çàëèøîê ìîëåêóëè ãë³êîãåíó), òî àêòèâîâàíà ÓÄÔ-ãëþêîçà ïðèºäíóºòüñÿ äî çàòðàâêè çà äîïîìîãîþ ãë³êîãåí-ñèíòåòàçíèõ (óòâîðþº 1,4–çâ‘ÿçêè) òà òðàíñãëþêîçèëàçíèõ (óòâîðþº 1,6–çâ‘ÿçêè) ôåðìåíòíèõ ñèñòåì, çá³ëü-øóþ÷è ìîëåêóëó ãë³êîãåíó íà îäíó ìîëåêóëó ãëþêîçè:

                             ÓÐÈÄÈÍ

                   CH2OH                 OH   

H                H                H      P Π                                                                     

                                                O                (Ñ6H10O5)n   ÓÄÔ

OH    OH    H      O–P=O                                             (C6H10O5)n+1        

                   H       OH   OH             

                   ÓÄÔ–ãëþêîçà                                  çàòðàâî÷íèé ãë³êîãåí

Âèñíîâîê:

ñèíòåç ãë³êîãåíó åíåðãîºìíèé ïðîöåñ (çàòðà÷àºòüñÿ 2-³ ìîëåêóëè ÀÒÔ); àâòîêàòàë³òè÷íèé (âåëèê³ ê³ëüêîñò³ â³ëüíîãî ãëþêîçî-6-ôîñôàòó àêòè-âóþòü ãë³êîãåíñèíòåòàçó–ïðîöåñè ãë³êîãåíåçó ïîñèëþþòüñÿ; ï³äâèùåí³ ê³ëüêîñò³ ÓÄÔ ³íàêòèâóþòü ãë³êîãåíñèíòåòàçó–ïðîöåñè ãë³êîãåíåçó ïðèïèíÿþòüñÿ). Óòâîðåííÿ ãë³êîãåíó ïðîõîäèòü ç ìàêñèìàëüíîþ øâèäê³ñòüþ ÷åðåç 30–40 õâ. ï³ñëÿ ïðèéîìó ¿æ³. Ïðîöåñè ãë³êîãåíåçó ïðîõîäÿòü ³íòåíñèâí³øå ï³ñëÿ àêòèâíî¿ ì‘ÿçåâî¿ ðîáîòè.

3.2 . Ãë³êîãåíîë³ç

 

Ïðè ì‘ÿçåâ³é ðîáîò³, ñèëüíîìó ïåðåîõîëîäæåíí³, ãîëîäóâàíí³, åìîö³éíîìó çáóäæåíí³ â³äáóâàºòüñÿ ïîñèëåíå ñïîæèâàííÿ êë³òèíàìè ãëþêîçè êðîâ³. гâåíü îñòàííüî¿ ïîâèíåí áóâ áè çíèæóâàòèñÿ. Ïðîòå, ó çäîðîâèõ ëþäåé ïðè ð³çíèõ ôóíêö³îíàëüíèõ ñòàíàõ, ð³âåíü ãëþêîçè ïîñò³éíèé (120 ìã/100ñì3) ç íåçíà÷íèìè â³äõèëåííÿìè. Ñòàá³ëüíèé ð³âåíü ãëþêîçè ó êðîâ³ çà ð³çíèõ ôóíêö³îíàëüíèõ ñòàí³â çàáåçïå÷óºòüñÿ ïðîò³êàííÿì ïðîöåñ³â ãë³êîãåíîë³çó (ðîçïàä ãë³êîãåíó äî ãëþêîçè). Ãë³êîãåíîë³ç ìîæå ïðîõîäèòè äâîìà øëÿõàìè: ã³äðîë³ç–ïîâ³ëüíèé, ìàëîåôåêòèâíèé ïðîöåñ; ôîñôîðîë³ç–îñíîâíèé øëÿõ ðîçïàäó ãë³êîãåíó.

Ôîñôîðîë³ç ïðîõîäèòü çà ó÷àñòþ ôîñôîðèëàçíèõ ôåðìåíòíèõ ñèñòåì, ÿê³ íà ïåðøîìó åòàï³ â³äùåïëþþòü â³ä ìîëåêóëè ãë³êîãåíó ê³íöåâ³ çàëèøêè ìîëåêóë ãëþêîçè ó âèãëÿä³ ãëþêîçî-1-ôîñôàòó:


1.

                                                                                       CH2OH

                                                                              H      H               H

          (C6H10O5)n            H3PO4; (C6H10O5)n-1                                              OH

                             ôîñôîðèëàçà                 OH   OH   H O–Р                                                                                             H               OH    OH

          Ãë³êîãåí                                                               Ãëþêîçî–1–ôîñôàò

2. Îñòàííÿ øâèäêî ³çîìåðèçóºòüñÿ â ãëþêîçî-6-ôîñôàò:

                                                                                                ÍΠ   ÎÍ   

                   CH2OH                                                       CH2O–Ð=Π       

 H               H                H                                   H      H               H     

                                                OH ôîñôîãëþêî³çîìåðàçà             

 OH   OH    H      O–P=O                         OH    OH   H OÍ

                   H       OH   OH                                 H               OH

                   Ãëþêîçî–1–ôîñôàò                                             Ãëþêîçî-6-ôîñôàò

3. Ãëþêîçî-6-ôîñôàò ðîçùåïëþºòüñÿ ôîñôàòàçàìè äî â³ëüíî¿ ãëþêîçè ³ ôîñôîðíî¿ êèñëîòè:

                    ÍΠ  ÎÍ                                         

                   CH2O–Ð=Π                                                CH2OÍ     

H                H                H                                   H      H               H     

                                                OH    ôîñôàòàçà                                         + Í3ÐÎ4

OH    OH    H      O–P=O                         OH    OH   H OÍ        

                   H       OH   OH    Í2Π          H               OH             

                   Ãëþêîçî–6–ôîñôàò                                             Ãëþêîçà

 

Âèñíîâîê:

ïîñò³éíà êîíöåíòðàö³ÿ ãëþêîçè ó êðîâ³ ï³äòðèìóºòüñÿ ïðîöåñàìè ãë³êîãåíîë³çó ÿê³ çíàõîäÿòüñÿ ï³ä êîíòðîëåì åíäîêðèííî¿ ñèñòåìè: ãîðìîí ãëþêàãîí ñòèìóëþº ïðîöåñè ðîçïàäó ãë³êîãåíó äî ãëþêîçè ó ïå÷³íö³ à àäðåíàë³í– ó ì‘ÿçàõ òà ³íøèõ âíóòð³øí³õ îðãàíàõ. Ïðîöåñè ãë³êîãåíîë³çó ïðèñêîðþþòüñÿ ïðè ïîñèëåí³é ì‘ÿçåâ³é ðîáîò³, ïåðåîõîëîäæåíí³, åìîö³éíîìó çáóäæåíí³. Íåçàëåæíî â³ä åíåðãîòðàò îðãàí³çìó çàâæäè â ïå÷³íö³ çàëèøàºòüñÿ ïåâíà ê³ëüê³ñòü ãë³êîãåíó (ðåçåðâ äëÿ ðîáîòè ãîëîâíîãî ìîçêó, ñåðöåâîãî ì‘ÿçó ³ «çàòðàâî÷íèé ãë³êîãåí»).

ϳäòðèìàííÿ ñòàíó ãîìåîñòàçó òà âèêîíàííÿ ïåâíèõ ô³çè÷íèõ âïðàâ ïðèâîäèòü äî ïîñèëåííÿ ïðîöåñ³â ðîçïàäó ãë³êîãåíó òà îêèñëåííÿ ãëþêîçè. Îñòàííº ìîæå â³äáóâàòèñÿ çà áåçêèñíåâèõ (àíàåðîáíèõ) óìîâ òà ó ïðèñóòíîñò³ êèñíþ (àåðîáíå îêèñëåííÿ).

Ïî÷àòêîâîþ ñòà䳺þ îêèñëåííÿ ãëþêîçè º àíàåðîáí³ ïåðåòâîðåííÿ.

 

3.3 Àíàåðîáíèé ðîçïàä ãëþêîçè (ãë³êîë³ç)

 

Óìîâíî ïîä³ëÿþòü íà äâ³ ñòà䳿 – ï³äãîòîâ÷ó ³ îñíîâíó.

ϳäãîòîâ÷à ñòàä³ÿ ãë³êîë³çó ðîçïî÷èíàºòüñÿ ç àêòèâàö³¿ ìîëåêóëè ãëþêîçè, ÿêà ÷åðåç ðÿä ôåðìåíòàòèâíèõ ðåàêö³é, ïåðåòâîðþºòüñÿ íà äâ³ ìîëåêóëè ôîñôîãë³öå-ðèíîâîãî àëüäåã³äó:


                                                                                                HO    OH

                   CH2OH                                                       CH2O–P=O                  

 H               H                H      ÀÒÔ ÀÄÔ H      H               H              

                                                                                                                            

OH    OH    H      OH   ãåêñîê³íàçà         OH    OH   H OH        

H       OH                                         H               OH             

Ãëþêîçà                                                     Ãëþêîçî–6–ôîñôàò     

                    HO   OH

                   CH2O–P=O                             ÍΠ   ÎÍ                                         

 H               H                H                         O=P–O–CH2                 OH             

                                      ôîñôîãëþêî³çîìåðàçà           H      HO                     

OH    OH    H      OH                                                                               

                   H       OH                                         H OH H      CH2OH

                   Ãëþêîçî–6–ôîñôàò                                   Ôðóêòîçî–6–ôîñôàò   

          O      

HO–P–OH                                                  HO    OH

 O–CH2                          OH                      O=P–O–CH2                 OH             

                                       ôîñôîôðóêòîê³íàçà               H      HO                     

H                H       OH                                                                      HO OH

                   OH    H      CH2ÎH                                   H OH H      CH2O–P=O

                   Ôðóêòîçî–6–ôîñôàò                                 Ôðóêòîçî–1,6–äèôîñôàò

          O      

HO–P–OH                                                                     OH                                

 O–CH2                          OH                                CH2–OP=O                    OH   

                                                àëüäîëàçà            C=O  OH    +       CH2–OP=O

H                H       OH             HO OH                 CH2–OH               CH=O OH 

                   OH    H      CH2ΖP=O                                                CH2–OH

                   Ôðóêòîçî–1,6–äèôîñôàò                 Äèîêñ³àöåòîíôîñôàò

          OH                                                              OH

CH2–OP=O                                                 CH2–O–P=O

CH=O OH                     ³çîìåðàçà                   CH–OH OH

CH2–OH                                                     C=O

                                                                   H

Äèîêñ³àöåòîíôîñôàò                        Ôîñôîãë³öåðèíîâèé àëüäåã³ä

Îòæå:

ï³äãîòîâ÷à ñòàä³ÿ ãë³êîë³çó ðåãóëþºòüñÿ äâîìà àëîñòåðè÷íèìè ôàêòîðàìè: ãåêñîê³íàçíèìè òà ôîñôîôðóêòîê³íàçíèìè ôåðìåíòíèìè ñèñòåìàìè, ÿê³ ïðè íèçüêèõ êîíöåíòðàö³ÿõ ÀÒÔ ó êë³òèí³ çàïóñêàþòü ïðîöåñè ãë³êîë³çó.  õîä³ ï³äãî-òîâ÷î¿ ñòà䳿 ãë³êîë³çó âèòðà÷àºòüñÿ äâ³ ìîëåêóëè ÀÒÔ.

Îñíîâíà ñòàä³ÿ ãë³êîë³çó – ñóêóïí³ñòü ôåðìåíòàòèâíèõ ðåàêö³é ïî ïåðåòâîðåííþ ôîñôîãë³öåðèíîâîãî àëüäåã³äó äî ï³ðîâèíîãðàäíî¿ ÷è ìîëî÷íî¿ êèñëîòè.

1. Îêèñëåííÿ ÔÃÀ. äî ôîñôîãë³öåðèíîâî¿ êèñëîòè çà ó÷àñòþ ôåðìåíòó ãë³öåð-àëüäåã³ä–3–ôîñôàòäåã³äðîãåíàçè (àêòèâíà ÷àñòèíà êîôåðìåíòó – ò³îëîâà ãðóïà òà îêèñëåíà ôîðìà ÍÀÄ+):


CH=O                  H–C–OH                                                   Ñ=Π          

CH–OH                         SF                                                    SF             

CH2–O–P=O + HS–F CH–OH                   ÍÀÄ+                   ÍÀÄÍÍ     CH–OH     

HO OH                 CH2–O–P=O                                               CH2–O–P=O

                                                HO OH                                             HO OH

                   ìàêðîåðã³÷íèé çâ‘ÿçîê

C=O                                                  C=O  OH                                 ÑOOH

 SF                                                    O–P=O                                   CH–OH

CH–OH                + H3PO4                                          OH              ÀÄÔ ÀÒÔ CH2–O–P=O

CH2–O–P=O        – HS–F                 CH–OH OH                                      HO OH

HO OH                                    CH2–O–P=O                                    

                                                                    OH                               

                                      1,3-äèôîñôîãë³öåðèíîâà êèñëîòà (ÔÃÊ)  3-ÔÃÊ

ÑOOH                                                                           COOH OH          

CH–OH                         ôîñôîãë³öåðîìóòàçà              CH–O–P=O        

CH2–O–P=O                                                                  CH2–OH OH                 

          HO OH                                                                                                      

3–ôîñôîãë³öåðèíîâà êèñëîòà                                      2–ôîñôîãë³öåðèíîâà êèñëîòà

2. Ïåðåòâîðåííÿ ôîñôîãë³öåðèíîâî¿ êèñëîòè äî ï³ðîâèíîãðàäíî¿ ÷è ìîëî÷íî¿ êèñëîòè:

COOH        OH                                 COOH OH                              COOH       

CH–O–P=O                   åíîëàçà (–Í2Î)    C–O–P=O   ÀÄÔ ÀÒÔ C=O           

CH2–OH     OH                                 CH2   OH                                 CH3                    

2–ÔÃÊ                 2–ôîñôîåíîëï³ðîâèíîãðàäíà êèñëîòà (ÏÂÊ)   ÏÂÊ          

COOH                                                                                     ÑÎÎÍ                 

C=O                               ÍÀÄ ÍÍ    ÍÀÄ+                                      ÑÍ–ÎÍ

CH3                                                                                                                                                     ÑÍ3                      ÏÂÊ                                                                                        ìîëî÷íà êèñëîòà

Îòæå:

â õîä³ ãë³êîë³çó âèä³ëÿºòüñÿ 6–7 % ïîòåíö³àëüíî¿ åíåð㳿 ãëþêîçè ó âèãëÿä³ 2 ìîëåêóë ÀÒÔ. ʳíöåâèìè ïðîäóêòàìè ãë³êîë³òè÷íèõ ïðîöåñ³â îêèñëåííÿ âóãëå-âîä³â º ï³ðîâèíîãðàäíà êèñëîòà (íîðìàëüí³ ô³ç³îëîã³÷í³ óìîâè) ÷è ìîëî÷íà êèñ-ëîòà (çà íåäîñòàòíüî¿ ê³ëüêîñò³ êèñíþ). Îñòàííÿ, ÿê ñèëüíà îðãàí³÷íà êèñëîòà, «çàêèñëþþ÷è» ñåðåäîâèùå ³íã³áóº àêòèâí³ñòü àëîñòåðè÷íèõ ôàêòîð³â, çàïîá³ãà-þ÷è ïåðåâòîì³.

Ó ìîëî÷í³é ÷è ï³ðîâèíîãðàäí³é êèñëîò³ ùå ì³ñòèòüñÿ äî 93 % ïîòåíö³éíî¿ åíåð㳿 ãëþêîçè, ÿêà âèä³ëÿºòüñÿ â çàêëþ÷í³é, àåðîáí³é ôàç³ ïåðåòâîðåííÿ âóãëåâîä³â. Àåðîáíà ôàçà õàðàêòåðèçóºòüñÿ ðîçïàäîì ïðîäóêò³â ãë³êîë³çó (ìîëî÷íî¿ êèñëîòè ÷è ÏÂÊ) äî âóãëåêèñëîãî ãàçó ³ âîäè ç âèä³ëåííÿì âåëèêî¿ ê³ëüêîñò³ åíåð㳿. ʳí-öåâèì àêöåïòîðîì åëåêòðîí³â ³ ïðîòîí³â º òêàíèííèé êèñåíü. Ñêëàäàºòüñÿ ç ï³ä-ãîòîâ÷î¿ ñòà䳿 ³ öèêëó òðèêàðáîíîâèõ êèñëîò.

3.4 Àåðîáíîãî ïåðåòâîðåííÿ âóãëåâîä³â

ϳäãîòîâ÷à ñòàä³ÿ àåðîáíîãî ïåðåòâîðåííÿ âóãëåâîä³â õàðàêòåðèçóºòüñÿ ïåðåòâî-ðåííÿì ÏÂÊ ÷è ìîëî÷íî¿ êèñëîòè â àêòèâíó ôîðìó àöåòèë–ÊîÀ. Íà äàíîìó åòàï³ âèä³ëÿºòüñÿ áëèçüêî 7 % åíåð㳿 ùî àêóìóëüîâàíà ó â³äïîâ³äíèõ ìåòàáîë³òàõ:

                                                                   CO2                                                  

COOH                                               ÑÎÎÍ        ÍÀÄ+          ÍÀÄÍ2                             

CH–OH      ÍÀÄ+                   ÍÀÄÍÍ     Ñ=Π           HS–ÊîÀ              ÑÍ3–Ñ=Π 

CH3             ëàêòàòäåã³äðîãåíàçà     ÑÍ3   ï³ðóâàòäåêàðáîêñèëàçà         S–KoA

Öèêë òðèêàðáîíîâèõ êèñëîò ñóêóïí³ñòü ôåðìåíòàòèâíèõ ðåàêö³é çà ó÷àñòþ òðèêàðáîíîâàíèõ êèñëîò. Âîíè ðîçïî÷èíàþòüñÿ âçàºìî䳺þ àöåòèë–ÊîÀ ç ùàâëåâî-îöòîâîþ êèñëîòîþ ³ çàê³í÷óþòüñÿ ðîçïàäîì ÿáëó÷íî¿ êèñëîòè äî ùàâëåâî-îöòîâî¿ êèñëîòè.  õîä³ äàíèõ ðåàêö³é â³äíîâëþºòüñÿ îêèñëåí³ ôîðìè äåã³äðîãåíàçíèõ ôåðìåíòíèõ ñèñòåì òà âèä³ëÿºòüñÿ âóãëåêèñëèé ãàç:

C=O            O=C–COOH                                    C=O

 SKoA        +       CH2             öèòðàòñèíòåòàçà  SKoA        H–OH – HS–KoA

CH3                                     COOH                                     CH2             àêîí³òàòã³äðàçà  

                                                                    HO– C–COOH                               

                                                                             CH2                                                                    

                                                                             COOH                                    

àöåòèë–ÊîÀ        ùàâëåâî-îöòîâà êèñëîòà        öèòðèë–ÊîÀ       

COOH                           COOH                            COOH                          

CH2                                CH2                                CH2                               

HO–C–COOH      – H2O                   C–COOH    +H–OH       CH–COOH ÍÀÄ ÍÀÄÍÍ

          CH2                                CH                       HO–CH               ³çîöèòðàò-–         

          COOH                           COOH                           COOH        äåã³äðîãåíàçà

ëèìîííà êèñëîòà                    öèñ-àêîí³òîâà                ³çîëèìîííà

                   – CO2                                      – CO2                                                                   

COOH                           COOH                                                        COOH       

CH2                                               CH2                      +ÍÀÄ+       ÍÀÄÍÍ     CH2            

CH–COOH                    CH2                      +ÍS–F        –CO2                  CH2            

C=O                               C=O                     –êåòîãëóòàðàò–                   C=O           

COOH                           COOH                  äåã³äðîãåíàçà                         S–KoA

ùàâëåâî–ÿíòàðíà                   –êåòîãëóòàðîâà                                                ñóêöèí³ë–ÊîÀ

                   COOH                                     ÑOOH        COOH                         

                   CH2                                         CH              CH2                              

ÃÄÔ  ÃÒÔ  CH2             ÔÀÄ+         ÔÀÄÍÍ CH       H–OH CH–OH ÍÀÄ+   ÍÀÄÍÍ

                   COOH                                     COOH        COOH       

                   ÿíòàðíà êèñëîòà                     ôóìàðîâà   ÿáëó÷íà êèñëîòà          

                                                         ÑOOH

                                                          CH2

                                                          C=O

                                                          COOH

                                                ùàâëåâî-îöòîâà êèñëîòà

Îòæå:

åíåðãåòè÷íèé åôåêò ï³äãîòîâ÷î¿õ ñòà䳿 àåðîáíîãî îêèñëåííÿ ñòàíîâèòü 6 ìîëåêóë ÀÒÔ (äâ³ â³äíîâëåí³ ôîðìè ÍÀÄ-çàëåæíèõ ôåðìåíò³â); åíåðãåòè÷íèé åôåêò öèêëó Êðåáñà {3 ÍÀÄÍÍ, 1ÔÀÄÍÍ, 1ÃÒÔ}=12 ìîëåêóë ÀÒÔ.

Ïîñê³ëüêè îäíà ìîëåêóëà ãëþêîçè ðîçêëàäàºòüñÿ íà äâ³ ìîëåêóëè ôîñôîãë³öåðè-íîâîãî àëüäåã³äó, òî çàãàëüíèé åíåðãåòè÷íèé åôåêò àåðîáíîãî îêèñëåííÿ ãëþêîçè ñòàíîâèòü 182=36 ìîëåêóë ÀÒÔ, à âðàõîâóþ÷è äâ³ ìîëåêóëè ÀÒÔ ãë³êîë³òè÷-íîãî îêèñëåííÿ –38 ìîëåêóë ÀÒÔ.

 38-è ìîëåêóëàõ ÀÒÔ àêóìóëþºòüñÿ ò³ëüêè 50 % ïîòåíö³éíî¿ åíåð㳿 ãëþêîçè (êÄæ) à ³íø³ 50 % âèä³ëÿþòüñÿ ó âèãëÿä³ òåïëà.


Ïèòàííÿ äëÿ ñàìîêîíòðîëþ

1. Ðîçêðèòè ñóòü ôåðìåíòàòèâíîãî ïåðåòâîðåííÿ âóãëåâîä³â ó õàð÷îâîìó òðàêò³ ëþäèíè.

2. Ïîøèðåííÿ âóãëåâîä³â ó îðãàí³çì³ ëþäèíè. Ô³ç³îëîã³÷íå çíà÷åííÿ ãëþêîçè.

3. Ñèíòåç ãë³êîãåíó ç ãëþêîçè (ãë³êîãåíåç). Õ³ì³çì ïðîöåñó, ôàêòîðè ðåãóëÿö³¿.

4. Ðîçïàä ãë³êîãåíó äî ãëþêîçè (ãë³êîãåíîë³ç). Õ³ì³çì ïðîöåñó, ôàêòîðè ðåãóëÿö³¿.

5. Õàðàêòåðèñòèêà ï³äãîòîâ÷î¿ òà îñíîâíî¿ ñòàä³é àíàåðîáíîãî ðîçïàäó (ãë³êîë³ç). Õ³ì³çì ïðîöåñó, ôàêòîðè ðåãóëÿö³¿, åíåðãåòè÷í³ åôåêòè.

6. Õàðàêòåðèñòèêà ï³äãîòîâ÷î¿ òà îñíîâíî¿ ñòàä³é àåðîáíîãî ðîçïàäó âóãëåâîä³â. Õ³ì³çì ïðîöåñó, ôàêòîðè ðåãóëÿö³¿, åíåðãåòè÷í³ åôåêòè.


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