MC LC

GVHD: ThS. Lm Khc K

Li m uGlucose l nhin liu ch yu ca hu ht cc c th sng v ng vai tr trung tm trong chuyn ha. S oxy ha hon ton glucose thnh CO2 v H2O theo phn ng C6H12O6 + 6O2 6CO2 + 6H2O gii phng mt nng lng t do. Glucose khng ch l mt nhin liu tuyt vi m cn l tin cht quan trng, c kh nng to nn mt lng ln cc cht chuyn ha trung gian, cc cht cn thit cho cc phn ng tng hp. T glucose c th tng hp c mt s amin, nucleotid, coenzyme, acid bo v nhiu cht chuyn ha trung gian cn thit cho s pht trin ca c th. Glucose c th c hng trm hoc hng ngn cch bin ha khc nhau. c th bc cao hoc ng vt, glucose c 3 s phn ch yu nh sau: c th c d tr di dng polysaccarid hoc saccarose, c oxy ha to thnh hp cht ba cacbon ( pyruvat) theo con ng ng phn hoc oxy ha to thnh cc pentose theo con ng pentose phosphat. Cng ging nh tt c cc con ng chuyn ha, chuyn ha glucid cng c c th iu ha mt cch cht ch. bit c s iu ha n din ra nh th no, nh hng ca c th khi c hay khng c c ch ny nhm chng ti chn ti C ch hnh thnh v hot ng ca glycogen. Vai tr v ngha sinh hc

Page 1

GVHD: ThS. Lm Khc K NI DUNG 1. Cu to ca glycogen Glycogen l cht d tr glucid ca ng vt, c th coi glycogen nh l "tinh bt" ca ng vt, v n cng gm 2 lin kt -D 1-4 v -D 1-6 glucoside, nhng n khc tinh bt ch l s r nhnh rm rp hn, c cch 8-10 phn t glucose c mt lin kt nhnh -D 1-6. Glycogen c nhiu gan ( chim 5-7% khi lng ca gan) c n chim 2% khi lng ca c, do khi lng c l ln nn glycogen c c l chnh. Hm lng ny c th bin ng ph thuc vo dinh dng v trng thi sinh l (i, no, lao ng, ng, thc...)

Hnh 1.1 Cu trc phn t glycogen 2.C ch hnh thnh Tng hp glycogen xy ra mi t chc nhng mnh nht l gan v c xng. gan, glycogen ng vai tr d tr glucose v sn sng cung cp glucose cho cc t chc khc s dng, ng thi n m bo mc ng huyt hng nh trong mu k c thi im xa ba n. Cn c, glycogen c dng thoi ha thnh glucose theo con ng ng phn, cung cp nng lng ATP cho s co c. Qu trnh tng hp glycogen bt u t G6P l sn phm do phn ng phosphoryl ha glucose xc tc bi hexokinase ( gan) v glucose kinase ( c):

Page 2

GVHD: ThS. Lm Khc K D-glucose + ATP D-glucose-6-phosphat +ADP

Hnh 2.1. Phosphoryl ha glucose Tuy nhin, phn ln G6P li l sn phm ca con ng tn to glucose; glucose trong thc n c hp thu vo mu, bin i thnh lactat ri c gan thu nhn v bin i thnh G6P. T G6P, n c ng phn ha thun nghch thnh G1P nh phosphoglucomutase: Glucose-6-phosphat Glucose-1-phosphat

Hnh 2.2. ng phn ha G6P

Page 3

GVHD: ThS. Lm Khc K Tip theo l phn ng then cht nht trong qu trnh tng hp glycogen: Phn ng to UDP-glucose (UDPG) xc tc bi UDPG pyrophosphorylase: Glucose-1-phosphat + UTP UDP-glucose + Ppi

Hnh 2.3. To UDP-glucose Phn ng xy ra theo chiu to UDPG v pyrophossphat b thy phn rt nhanh thnh ortophosphat nh c pyrophosphat v c. UDPG chnh l cht trung gian bin i galactose thnh glucose. N chnh l cht cho gc glucose trong qu trnh tng hp glycogen di tc dng ca glycogen synthase. C th c hai trng hp xy ra: 2.1 Trng hp c chui glucan sn Enzym glycogen synthase xc tin vic chuyn gc glycosyl t UDPG ti gn vo u khng kh (C-4) ca mt phn t glycogen c n gc glucose c sn (hnh 8.24) to thm mt lin kt mi ( -14) glucosid, ngha l to thnh glycogen c n+1 gc glucose.

Page 4

GVHD: ThS. Lm Khc K

Hnh 2.4. Tng hp mc thng ca glycogen

Khi to thm t nht 6 phn t glucose th enzym gn nhnh amylose (14-16)transglycosylase hay glycosyl (46)- tranferase c tc dng va ct t lin kt (14)- glycosid ca on glycogen mi to ra, va chuyn n gn vo OH ca C-6 ca gc glucose trn cng mt chui hay chui khc to ra mt im nhnh mi (-16) trong qu trnh sinh tng hp glycogen (hnh 2.5)

Page 5

GVHD: ThS. Lm Khc K Hnh 2.5. S to thnh mt im nhnh (-16) trong qu trnh tng hp glycogen bi enzym gn nhnh Sau mch nhnh mi to thnh li c ko di ra nh tc dng ca enzym glycogen synthase dn n to cc lin kt mi (-14) glycosid. Qu trnh trn c lp li lm cho s lng mch nhnh tng dn ln cho n khi t c mt phn t glycogen c cu trc ph hp vi nhu cu ca t bo. Nh vy, tc dng sinh hc ca s gn nhnh l lm cho phn t glycogen d tan hn v s u khng kh ca n tng ln, do phn ng c nhiu hn vi c glycogen phosphorylase v glycogen synthase. 2.2 Trng hp khng c chui glucan sn M u cho qu trnh tng hp glycogen cn phi c mt cht mi protein gi l glycogenin (M 37284): cht ny c tm thy u kh ca cc phn t glycogen. Qu trnh tng hp din bin theo 5 giai on (hnh 2.6): - Giai on 1: Mt gc glucose t UDPG gn vo gc Tyr194 ca glycogenin nh xc tc ca protein-tyrosine-glycosyl transferase. - Giai on 2: To phc hp ca glycogenin gn glucose vi glycogen synthase theo t l 1:1. - Giai on 3: Ko di chui glucan cho ti khi to chui gm 7 gc glucose hay nhiu hn. Mi gc glucose mi gn vo u i t UDPG v l nhng phn ng t xc tc thng qua glycosyl transferase ca glycogenin. - Giai on 4: Glycogen synthase tch dn khi glycogenin. - Giai on 5: Hon thnh phn t glycogen nh phi hp tc dng ca glycogen synthase v enzym gn nhnh (glycogen branching enzym). Cui cng, glycogenin vn gn vo mt u ca phn t glycogen c to thnh.

Page 6

GVHD: ThS. Lm Khc K

Hnh 2.6. Tng hp glycogen bng mt cht mi protein (Glycogenin)

Page 7

GVHD: ThS. Lm Khc K 3.C ch hot ng ca glycogen (thoi ha glycogen) Qu trnh ny xy ra ch yu cc t bo gan. Trong c th ngi v ng vt, glycogen l dng d tr ca mi t bo. Trong , gan ri n c c t l glycogen trn t chc l cao hn c. m gan, s thoi ha glycogen, ngoi mc ch cung cp glucose cho chnh n cn to ra mt lng ln glucose t do theo mu ngoi bin cung cp cho cc m khc. V vy, cc thi im xa ba n (lc i), s thoi ha glycogen ca gan c vai tr quan trng trong s iu ha hm lng glucose trong mu. t chc c , khi t bo hot ng, s tiu hao nng lng i hi phi c cung cp mt lng ln Glucose thoi ha. Ngoi ngun glucose do mu mang n, t bo c phi thoi ha rt mnh glycogen d tr to glucose- 6- phosphat cho qu trnh t chy. S thoi ha glycogen n glucose trong cc t bo c thc hin nh mt h thng enzyme bao gm: phosphorylase l enzyme thy phn cc lin kt 1-4-glucosid vi s tham gia ca mt gc phosphate, gii phng cc phn t glucose 1 phosphat u tn cng ca mch polysaccarid. Phosphorylase tn ti di dng 2 phn t: dng phosphorylase a hay phosphophosphorylase l dng hot ng, trong phn t c gn gc phosphate v gc serin ca n. Phosphorylase b l dng khng hot ng (dephosphophosphorylase), trong phn t khng cha gc phosphate. Hai dng ny, ty thuc tnh trng chuyn ha glycogen trong m, c th chuyn ha qua li nh h thng enzyme kinase (gn gc phosphat) hoc phosphatase (tch gc phosphat): 2 Phosphorylase + 4 ATPphosphorylase b kinase

Phosphorylase a + 4 ADP

Phosphorylase

Phosphorylase a + 4 H2O

Phosphatase

2 Phosphorylase b + 4Pi

Cc enzyme xc tc s chuyn dng phn t ca phosphorylase chu nh hng ca nhiu yu t iu ha nh hormone, cc sn phm to ra trong qu trnh chuyn ha ca t bo khi m hot ng V vy, mi m cc enzyme ny c s hot ng c th

Page 8

GVHD: ThS. Lm Khc K khc nhau, s iu ha hot ng ca chng cng theo nhng c ch khc nhau. S khc bit ny r rt nht hai m gan v c. Enzyme ct nhnh (debranching enzyme) l mt enzyme c hai chc nng, chc nng th nht l chc nng chuyn nhnh (transferase), c tc dng ct lin kt 1-4glucosid st gc nhnh ri chuyn mt on mch thng n gn vo mt on mch khc bng cch to ra mt lin kt 1-4 glucosid khc. Enzyme ct nhnh cn c chc nng th hai l th hin hot tnh amylo 1-6 glucosidase, c tc dng thy phn lin kt 1-6 glucosid ca cc nhnh ch cn li mt phn t glucose, gii phng phn t glucose t do. Cc giai on thoi ha: Hai enzyme chnh tham gia vo qu trnh thoi ha glycogen thnh glucose l glycogen phosphorylase v phosphoglucomutase. C th chia thnh 3 giai on: 3.1 Thy phn mch thng ca phn t glycogen Glycogen phosphorylase xc tc phn ng ct gc glucose tn cng u khng kh ca mch thng glycogen. l phn ng thy phn lin kt 1-4 glucosid vi s tham gia ca phosphat v c (Pi) to thnh D-glucose-1-phosphat (G1P) v chui mach thng ca phn t glycogen ngn i mt phn t glucose (hnh 3.1).

Page 9

GVHD: ThS. Lm Khc K

Hnh 3.1 Thy phn mch nhnh ca glycogen Qu trnh ny c lp li nhiu ln, tch dn tng gc glucose di dng G1P cho ti khi mch ang thoi ha ch cn li 4 n v glucose ti mt im nhnh ( 1-6) th dng li (hnh 3.2). Tip , enzyme ct nhnh th hin hot tnh chuyn nhnh s ct mt on 3 gc glucose ca on cn li, bng cch thy phn lin kt 1-4 glucosid gia gc th nht v th hai tnh t gc nhnh, ri chuyn on c 3 gc glucose n gn vo u mt chui thng khc bng cch to mt lin kt 1-4-glucosid khc. Nhnh glycogen mi ny s di thm 3 gc glucose, to iu kin cho phosphorylase tip tc tc dng. Phn mch nhnh cn li ch cn mt gc glucose vi lin kt 1-6 glucosid. Nh vy, sn phm ca qu trnh thy phn mch thng ca phn t glycogen l cc phn t glucose 1 phosphat (G1P).

Page 10

GVHD: ThS. Lm Khc K + Phn ng xc tc ca phosphorylase ny khng ging vi phn ng thy phn lin kt glycosid bi amylase trong ng tiu ha i vi glycogen hay tinh bt: Mt s nng lng ca lin kt c gi li trong qu trnh to este G1P. + Pirydoxal photphat l cofactor ch yu trong phn ng xc tc ca glycogen phosphorylase, nhm phosphat ca n ng vai tr l mt cht xc tc acid kch thch Pi tn cng vo lin kt glycosid (khc vi vai tr cofactor ca pyridoxal phosphat trong chuyn ha acid amin).

3.2 Thy phn mch nhnh ca phn t glycogen Khi mch nhnh ch cn li mt gc glucose, enzyme ct nhnh th hin hot tnh amylo 1-6 glucosidase, thy phn lin kt 1-6 glucosid ca gc glucose cn li nhnh gii phng ra glucose t do. Nh vy, di tc dng ca h thng enzyme thoi ha glycogen nu trn, phn t glycogen s chuyn hon ton thnh cc phn t glucose 1 phosphat (93%) v glucose t do (khong 7%). Page 11

GVHD: ThS. Lm Khc K cc m, G1P s c ng phn ha nh enzyme phosphoglucomutase to thnh glucose 6 phosphat (G6P). Glucose t do cng c phosphoryl ha vi s tham gia ca 1 phn t ATP v enzyme hexokinase to G6P. G6P s i vo cc con ng thoi ha tip theo.

Hnh 3.3. Hot tnh amylo 1-6 glucosidase Ring m gan, ch mt phn nh G6P c tip tc thoi ha p ng nhu cu chuyn ha ca t bo gan, cn li phn ln G6P s b thy phn nh tc dng ca enzyme glucose 6 phosphatase to thnh glucose t do, thm qua mng t bo, vo mu tun hon. Enzyme glucose 6 phosphatase ch c trong m gan v vy ch c gan mi c kh nng cung cp lng glucose ni sinh cho mu tun hon. Cng v vy, gan c vai tr rt quan trng trong vic iu ha ng huyt. 4. Vai tr v ngha sinh hc ca glycogen 4.1 Glycogen l ngun nng lng quan trng ca c th Glycogen l ngun nng lng quan trng ca c th v l ngun nng lng chnh cho cc vn ng. V mt ha hc, glycogen ch n gin l mt carbohydrate phc - c

Page 12

GVHD: ThS. Lm Khc K bit l mt polysaccharide, y l mt chui polymer di ca cc phn t ng glucose. V mt sinh hc, glycogen to thnh mt ngun tch tr nng lng t carbohydrate trong c th. Nng lng ny c s dng khi c th t ngt cn lng ng glucose ln, v d in hnh l khi luyn tp vi cng cao trong thi gian ngn. Glycogen c tch tr ch yu trong gan v trong cc t bo c xng. Mc d phn trm glycogen trong t bo c (1-2%) t hn nhiu so vi trong gan (8-10%), tng lng glycogen trong t bo c li ln hn nhiu do khi lng c ln trong c th. Vy ngun nng lng tch tr t glycogen khc vi ngun nng lng tch tr t m. Th nht, glycogen bn cht l carbohydrate cha t nng lng hn so vi m, nhng lun sn sng c s dng. Thm na, glycogen tch tr ch yu gan v c, khc vi m c phn b khp c th di dng m di da. Nng lng t glycogen sinh ra khi phn tch thnh tng phn t glucose ring l (vi tc ng ca enzyme glycogen phosphorylase), y l ngun nng lng chnh cho t bo. Trong gan, qu trnh ny c bt u bi glucagon, mt hormone sn xut bi tuyn ty. Lng glucagon lin quan trc tip vi lng ng / glucose trong mu. 4.2 Tc dng n nh ng huyt Khi ng huyt thp - khi bn s cm thy mt mi, ui sc - nhiu glucagon gan v adrenalin c c tit ra, hormone ny khi li lnh cho gan phn r glycogen thnh ng glucose v chuyn vo mu a ng huyt v mc bnh thng. Khi ng huyt cao, hormon insuline li c tit ra, n lnh cho gan tng hp glycogen t glucose v tch tr glycogen a ng huyt v mc bnh thng. Khi ng huyt v mc bnh thng, bn bt u cm thy c th di do nng lng tr li. Nh vy ngoi vic cung cp nng lng, glycogen cn c tc dng n nh ng huyt. Trong c bp s phn r glycogen c kch thch bi vn ng co gin c, nh din ra trong khi luyn tp. Cc bi tp cng nng, cng nhiu glycogen c th phi chuyn thnh glucose cung cp nng lng. Tuy nhin v gan ch c th ct tr c mt

Page 13

GVHD: ThS. Lm Khc K lng gii hn glycogen, cui cng bn cng s cn kit lng glycogen nu bn khng cung cp tr li cho c th. Phi ni thm rng glycogen trong gan s c chuyn ha vo mu v a ti tt c cc c quan. Ngc li, glycogen trong c bp ch c th c s dng bi c bp do c bp khng c enzyme gip chuyn glucose vo mu. 4.3 Bnh d tr glycogen (Glycogen Storage Disease = GSD) 4.3.1 Khi nim Glucose l ngun nng lng ln ca c th. N c d tr di dng glycogen v sau c phng thch cho vic s dng di tc ng ca mt s enzymes. Bnh d tr glycogen (GSD) l mt nhm ri lon bm sinh trong mt lng hoc mt dng glycogen bt thng c d tr trong gan. N l hu qu t thiu st ca gan trong vn iu ho chuyn ho glycogen v glucose. Bnh d tr glycogen xy ra khi thiu enzyme glucose-6-phosphatase iu ho s chuyn i ca glucose t dng d tr l glycogen. Nhng loi ng d tr di dng glycogen cn phi c x l bi cc enzymes trc khi c th s dng. Khi thiu nhng enzymes cn thit x l chng, cc glycogen ny hoc mt trong nhng cht tinh bt lin quan n chng s tch t li gy ra ri lon. C t nht 10 typ bnh d tr glycogen khc nhau, chia thnh tng nhm da trn loi enzyme b thiu. Cc th bnh d tr glycogen (GSD) chia thnh cc typ I, III v IV. C khong 20.000 dn l c mt ngi b bnh d tr glycogen +GSD I : cn gi l bnh von Gierkes do thiu enzyme Glucose-6-Phosphatase. +GSD III cn gi l bnh Cori: vi type bnh d tr glycogen ny, thiu enzyme debrancher khin c th to ra nhng phn t glycogen c cu trc bt thng. Cu trc bt thng ny ngn cn glycogen ly gii thnh glucose t do.

Page 14

GVHD: ThS. Lm Khc K +GSD IV cn gi l bnh Amylopectinosis: trong bnh d tr glycogen type IV ny, khng thy c tng lng glycogen trong cc m. Thay vo , glycogen tch lu c rt nhiu nhnh di bn ngoi, do khim khuyt v di truyn ca enzyme phn nhnh (branching enzyme). Glycogen bt thng ny kch thch h min dch ca c th to ra cc khng th t min. Hu qu l hnh thnh nhiu x so trong gan, tim v cc bp c. 4.3.2 Nguyn nhn Khi glucose c chuyn i thnh glycogen, mi bc u cn c mt enzyme khc nhau. Khi mt trong nhng enzymes ny c bt thng v khng m nhn c vai tr ca mnh, qu trnh chuyn ho s ngng li. Cc khim khuyt enzyme chuyn i ny s gy ra bnh d tr glycogen (GSD). GSD l mt bnh di truyn xy ra do tha hng gene khim khuyt t c cha ln m . Nu c cha ln m u mang gene khim khuyt, s c: +Kh nng 25% con ca h s mc bnh +Kh nng 50% con h s nhn c mt gene khim khuyt t cha hoc m, ngha l con s khng c triu chng bnh nhng c mang mm mng ca bnh. +Kh nng 25% con ca h s nhn c c hai gen bnh thng t cha m v s khng mc bnh GSD 4.3.3 Triu chng v du hiu ca bnh Triu chng thay i tu theo enzyme b thiu. Triu chng thng l hu qu ca vic tch t glycogen hoc do vic mt kh nng sn xut ra glucose khi cn thit. Do bnh d tr glycogen (GSD) ch xy ra ch yu cc c v gan, cc v tr ny s bc l triu chng r nht. Cc triu chng bao gm: + Ri lon tng trng + Chut rt (vp b)

Page 15

GVHD: ThS. Lm Khc K + H ng huyt + Gan ln + Bng to Tui khi xut hin triu chng v nng nh tu thuc vo type ca GSD. Tr em b GSD typ I t khi pht trin thnh x gan, nhng chng s c nguy c cao b adenoma gan. C th ni rng GSD typ III l mt dng nh hn ca GSD typ I. cng l mt nguyn nhn him gp gy suy gan. Tuy nhin, n c th gy si ho gan (liver fibrosis =ho so sm ca gan, do nhng tn thng, nhim trng hoc phn ng vim khi hi phc to thnh). Glycogen tch t trong gan s khin t bo gan sng ph lnGan to ra v thoi ho m Bnh d tr glycogen tp II l mt bnh ca c v khng gy nh hng g n gan. Bnh d tr glycogen tp IV gy x gan; n cn c th gy ra nhng ri lon v chc nng ca tim v cc c. Tr em b GSD typ IV bm sinh c chn on da trn gan to v khng tng trng trong nm u tin; chng thng pht trin thnh x gan khi c 3 5 tui. 4.3.4 Cc type bnh d tr glycogen Cc Triu chng v du hiu, ngoi tnh trng tch t glycogen +Typ I, Gan thiu enzyme Glucose-6-phosphatase (Bnh von Gierke's ) H ng huyt lc i, gan ph i +Typ IV, thiu enzyme phn nhnh (branching enzyme) nhiu c quan, k c gan (BnhAndersen's=amylopectinosis) Ri lon chc nng gan v t vong sm. +Typ V, Thiu enzyme Glycogen Phosphorylase c (Bnh McArdle's) vp b c khi vn ng.

Page 16

GVHD: ThS. Lm Khc K +Type VII, c thiu enzyme Phosphofructokinase. Khng th vn ng

Hnh 4. Cc loi bnh GSD 4.3.5 Chn on bnh Bn du hiu quan trng nht ca GSD typ I, III v IV l: + H ng huyt + Gan to + Cc ri lon tng trng +Kt qu xt nghim mu bt thng, men gan tng, ri lon chuyn ho lipid, tng uric acid mu v.v.

Page 17

GVHD: ThS. Lm Khc K Thc hin xt nghim mu m gan xem c thiu mt s enzym hay khng? Chn on xc nh bng cch sinh thit c quan b tn thng, cho thy c tch t glycogen v mt hot ng ca cc enzyme. 4.3.6 iu tr - iu tr tu thuc vo typ ca bnh d tr glycogen (GSD). Mt s type GSD khng th iu tr c, s khc tng i d kim sot bng cch iu tr cc triu chng. - i vi nhng tp GSD c th iu tr c, bnh nhn cn tun th k mt ch n c bit. - Cn cho tr n nhng ba n giu carbohydrate trong ngy. i vi mt s bnh nhi, n nhiu ba n nh nhiu ng bt mi ngy s trnh c bin chng h ng huyt. Tinh bt bp (cornstarch): i vi mt s tr nh trn 2 tui, cho ung bt bp cha nu mi 4 n 6 gi k c ban m cng gip gim nh vn . Nui n lin tc ban m: duy tr lng ng mu, t ng sonde d dy mi ti v bm dung dch nng glucose cao. iu ny s gip kim sot c lng ng mu. Cn dng ng sonde d dy mi ti cho tr nh , nhng sau ny khi chng ln ln th c th s khng cn cn thit na. Ban ngy s rt sonde d dy, nhng bnh nhi s cn phi n nhiu thc n giu ng bt mi 3 gi. Cch thc iu tr ny c th hiu qu trong vic ci thin li tt c cc triu chng ca bnh. Thuc men: bnh d tr glycogen (GSD) c khuynh hng khin cho acid uric (mt loi cht thi) tch lu li, to ra bnh gout (vim au nhc cc khp) v si thn. Thuc men (allopurinol) i khi cn thit phng nga tnh trng ny. Trong mt s type bnh GSD (c bit type II), tr cn gii hn hot ng th lc gim thiu tnh trng chut rt (vp b) ca cc c. KT LUN

Page 18

GVHD: ThS. Lm Khc K Glycogen l cht d tr glucid ca ng vt, c th coi glycogen nh l "tinh bt" ca ng vt, c nhiu gan ( chim 5-7% khi lng ca gan) c n chim 2% khi lng ca c, do khi lng c l ln nn glycogen c c l chnh. Khi nng glucose trong mu tng cao, glycogen c tng hp. Qu trnh tng hp glycogen xy ra mi t chc nhng mnh nht l gan v c xng. gan, glycogen ng vai tr d tr glucose v sn sng cung cp glucose cho cc t chc khc s dng, ng thi n m bo mc ng huyt hng nh trong mu k c thi im xa ba n. Cn c, glycogen c dng thoi ha thnh glucose theo con ng ng phn, cung cp nng lng ATP cho s co c. Glycogen l ngun nng lng quan trng ca c th v l ngun nng lng chnh cho cc vn ng. V mt sinh hc, glycogen to thnh mt ngun tch tr nng lng t carbohydrate trong c th. Nng lng t glycogen sinh ra khi phn tch thnh tng phn t glucose ring l (vi tc ng ca enzyme glycogen phosphorylase), y l ngun nng lng chnh cho t bo. Ngoi vic cung cp nng lng, glycogen cn c tc dng n nh ng huyt. Qu trnh tng hp glycogen, mi bc u cn c mt enzyme khc nhau. Khi mt trong nhng enzymes ny c bt thng v khng m nhn c vai tr ca mnh, qu trnh chuyn ho s ngng li. Cc khim khuyt enzyme chuyn i ny s gy ra bnh d tr glycogen (GSD). GSD l mt bnh di truyn xy ra do tha hng gene khim khuyt t c cha ln m .

Page 19

GVHD: ThS. Lm Khc K TI LIU THAM KHO 1. GT Ha sinh hc, H dc H Ni, GS.TS Nguyn Xun Thng ch bin, NXB Y hc-2004 2. GT Ha sinh, H Y H Ni, GS.TS Nguyn Hu Chn ch bin, NXB Y hc2001 3. GT Ha sinh ng vt, H Nng nghip H Ni, NXB Nng nghip 2005 4. http://en.wikipedia.org/wiki/Glycogen 5. http://vothinhpleiku.blogspot.com/2010/11/vai-tro-cua-glycogen-trong-tapluyen.html 6. http://tailieu.vn/xem-tai-lieu/benh-du-tru-glycogen.122182.html

Page 20