Ha sinh i cngPDI by http://www.ebook.edu.vn3 Bai2 CHUYN HOA CHUNG CUA CAC CHT Muc tiu: 1. Giai thich duoc ban cht cua su h hp t bao. 2. K duoc cac lin kt phosphat giu nang luong quan trong trong co th sng. 3. Trlnh bay duoc duoc cac giai doan cua chu trlnh Krebs. 4. Tinh duoc nang luong giai phong cua su h hp t bao, chu trlnh Krebs. 5. Nu ra duoc y nghia cua su h hp t bao, su phosphoryl hoa va chu trlnh Krebs. I. KHAI NIM V CHUYN HOA CAC CHT 1. ai Cuong Trongquatrlnhsng,cothsnglunlunphaitraodichtvoimi truong bn ngoai: dua thuc an tu mi truong vao co th va dao thai cac cht can ba ra mi truong. Cac qua trlnh trao di tin hanh duoc la nho nhung phan ung hoa hoc lin tuc xay ra trong co th. Cac phan ung hoa hoc lin tuc xay ra trong co th sinh vt la cac phan ung hoa sinh. Nhiu phan ung hoa hoc xay ra lin tip taonnmtchuiphanung.Cacphanungvachuiphanunghoasinhvoi nhung mi lin quan chang chit, tao nn qua trlnh chuyn hoa cac cht cokem theo qua trlnh trao di nang luong: tu cht nay sang cht khac, tu dang nay sang dang khac. Theodacdimchuynhoacacchtvachuyndangnangluong,nguoita chia sinh vt ra lam hai loai lon: Sinh vt tu duong (SVTD): chu yu la thuc vt, co kha nang tng hop cac cht huu co: glucid (G), lipid (L), protid (P)... tu cac cht v co don gian: CO2, H2O, N...CO2 H2O NQuanghop G, L, P Sinh vt di duong (SVDD): gm nguoi va dng vt, co th tng hop G, L, P...dachiuchocothtuG,L,P...cuathucan.SVTDlamttrongnhung ngun thuc an cua SVDD. Qua trlnh thoai hoa G, L, P cua SVDD cung cp nang luongchocothsudung,dngthoidaothairamitruongCO2,H2O,ur..., Ha sinh i cngPDI by http://www.ebook.edu.vn4 SVTDlailylamnguynliudtnghopnnG,L,Ptaonnchutrlnhkhep kin.Quatrlnhchuynhoacacchtquanhiukhutrunggianvanhiucht trung gian. Qua trlnh chuyn hoa trung gian do bao gm rt nhiu phan ung v cung phuc tap. Nguoi ta co th chia lam hai loai qua trlnh: dng hoa va di hoa. 2. Qua trlnh dng hoa va di hoa 2.1. Qua trlnh dng hoa La qua trlnh bin di G, L, P tu ngun gc khac nhau (thuc vt, dng vt, vi sinh vt) thanh G, L, P dac hiu cua co th. Bao gm: Tiu hoa: La qua trlnh thuy phn cac dai phn tu: G, L, P co tinh dac hiu cua thuc an thanh cac don vi cu tao khng co tinh dac hiu nhu monosaccarid, acid beo, acid amin... su tiu hoa nay nho cac enzym trong dich tiu hoa. Hpthu:Sanphmcuicungcuaquatrlnhtiuhoaduochpthuqua nim mac rut non, vao mau d dua dn t bao, m. Tng hop: o t bao va m, nhung cht trn duoc su dung lam nguyn liu d tng hop nn G, L, P dac hiu cua co th. Qua trlnh dng hoa cn duoc cung c p nang luong. 2.2. Qua trlnh di hoa: La qua trlnh phn giai cac cht G, L, P,... thanh nhung san phm trung gian, dntoinhungchtcanbaddaothairangoainhuCO2,H2O,ur,aciduric,... Qua trlnh nay gm nhiu loai phan ung: oxy hoa khu, thuy phn, chuyn nhom, tachnhom...Trongdoquatrlnhoxyhoakhusinhhocdongvaitroquantrong Hlnh 2.1: So d mi lin quan cua SVTD va SVDD G,L,P CO2,H2O,N SVTDSVDD Quang hop O2 Nang luong Ha sinh i cngPDI by http://www.ebook.edu.vn5 nht trong su giai phong nang luong. Nang luong nay, mt phn duoc toa ra duoi dang nhit (50), mt phn duoc tich tru duoi dang ATP (khoang 50). Nangluongdutruduocsudungchocacphanungtnghopvacachoat dng sinh ly nhu co co, hp thu va bai tit, dn truyn xung dng thn kinh,... 3. ac dim cua qua trlnh trao di cht Qua trlnh chuyn hoa trong co th sng mang tinh thng nht va rng bit. Nhlnchungcacconduongchuynhoalontrongmoicothtudngvt,thuc vt, don bao, da bao du theo nhung giai doan tuong tu nhau. Tuy nhin, di su tung m, co quan, ca th, tung loai thl lai co nhung net ring bit. Cac pha n ung hoa hoc trong co th xay ra lin tuc, trong diu kin pH trung blnh, nhit d 370C, va enzym xuc tac. Odngvtcacquatrlnhchuynhoaduocdiukhinboihthngthn kinh. 4. Y ngha cua vic nghin cuu qua trinh trao di cht di voi yduoc hoc Nam duoc quy lut bin hoa cua vt cht d diu khin theo huong co loi cho suc khoe con nguoi Hiuduocnguynnhnbnhdoriloanchuynhoa,chndoanbnh som, chinh xac. Giai thich tac dung duoc ly thuc giup cho cng tac nghin cuu thuc moi hoan thin.Trao di cht va trao di nang luong la ban cht cua hoat dng sng o moi sinh vt. Song song voi su trao di ch t bao gio cung co qua trlnh kem theo qua trlnh trao di nang luong. II. SU H HP T BAO (HHTB) Su HHTB la su dt chay cac cht huu co trong co th (con goi la su oxy hoa khu t bao hay su oxy hoa sinh hoc). 1. Khai nim oxy hoa khu inh ngha: Qua trlnh trao di oxy hoa khu la qua trlnh trao di din tu. Su oxy hoa la su tach mt hay nhiu din tu, nguoc lai, su khu oxy la su thu din tu.Song song voi su oxy hoa co su khu oxy vl din tu duoc chuyn tu cht bi oxy hoa sang cht bi khu . Thi du: 2Ie2Cl22Ie32Cl 2e Ha sinh i cngPDI by http://www.ebook.edu.vn6 Trongphanungoxyhoakhu,thnangoxyhoakhuduoctinhtheo phuong trlnh Nernst: khox0CClnnRTE E+ =Trong do: E th nang oxy hoa khuE0 th nang oxy hoa khuR hang s khi T nhit d tuyt di tri s Iaraday (96,500 Coulomb hay 23,07 Kcal.vol1.mol1) n s din tu di chuyn Cox nng d dang oxy hoa trong dung dich Ckh nng d dang khu trong dung dich Tathy,hiuthEphuthucvaotylgiuanngddangoxyhoava dang khu. Nu Cox Ckh thl E Eo. Vl vy, trong thi nghim, mun xac dinh E0 ta cho:|Ie2] |Ie3] 1 mol Dua vao th nang oxy hoa khu cua mt h thng, co th xac dinh vi tri cua h thng nay trong dy chuyn phan ung oxy hoa khu. Thi du: ta co hai h thng oxy hoa khu: Th nang oxy hoa khu chun cua hai h thng nay la EoA va EoB. Nu EoA thp hon EoB thl din tu co chiu huong chuyn tu A sang B, co ngha la A se bi oxyhoavaBsebikhu.Hthngcothnangoxyhoakhucaonhtselah thng oxy hoa manh nht, noi cach khac h thng co th nang oxy hoa khu cang cao bao nhiu thl kha nang nhn din tu cua h thng cang lon by nhiu. NusuchnhlchgiuahaithnangEoBvaEoAlon,phanungthuongla khng thun nghich va nang luong duoc toa ra thanh mt luong nhit lon. iu nay rt him thy trong t bao sinh vt. Cac phan ung trong t bao thuong co d chnh lch nho v th nang oxy hoa khu (phan ung co tinh thun nghich), nang AkhAox e BkhBox e Ha sinh i cngPDI by http://www.ebook.edu.vn7 luongduocgiaiphongtuongdiitvanunangluongvuotquamucnhtdinh thl se duoc tich tru lai duoi dang cac lin kt hoa hoc. Su tuong quan giua th nang oxy hoa khu va bin thin nang luong tu do biu din bang phuong trlnh sau: Io nEo Trong do: Io bin thin nang luong tu do cua phan ung. Eo hiu s th nang oxy hoa khu cua h thng tri s Iaraday n s din tu di chuyn. Bang 2.2.Th nang oxy hoa khu chun cua mt s h thng H thngE0 (volt) Dang khu Dang oxy hoapH 7,t0 250 H2 NADHH RiboIlavin dang khu Ubiquinon dang khu Cytocrom b (Ie2) Cytocrom C1 (Ie2) Cytocrom c (Ie2) Cytocrom a (Ie2) H2O 2H NAD RiboIlavin dang oxy hoa Ubiquinon dang oxy hoa Cytocrom b (Ie3) Cytocrom C1 (Ie3) Cytocrom c (Ie3) Cytocrom a (Ie3) 1/2O2 0,42 0,32 0,05 0,10 0,12 0,21 0,25 0,29 0,82 2. Ban cht cua su HHTB Trongcothsudtchay(suoxyhoakhu)cacchthuucochosanphm cuicunglaCO2vaH2O.Trongdosukthophydrovaoxytaothanhnuoc duoc goi la su HHTB. O ngoai co th, oxy cua khng khi truc tip tac dung voi carbon va hydro cua cac cht huu co d tao thanh CO2 va H2O. Phan ung xay ra rt nhanh chong, manh me; nang luong duoc giai phong ra ngay mt luc; nhit d cao va co th co ngon lua. Ongoaicoth,oxykhngtructiptacdungvoicarbon,hydrocuacht huuco.Phanungxayratutu,tungbuoc;nangluongduocgiaiphongdnva Ha sinh i cngPDI by http://www.ebook.edu.vn8 duoc tich tru lai nu co th chua cn khng tang nhit d cao va khng co ngon lua: TaoCO2:dobikhucarboxylcuaphntuhuuconhoenzym decarboxylase; phan ung khng giai phong nhiu nang luong. RCOOHRH CO2

TaoH2O:nuocduoctaothanhnhomtdychuynphanungbaogm hang loat qua trlnh tach dn hydro ra khoi co cht va vn chuyn hydro qua mt chui dai cac cht trung gian, cui cung toi oxy. Trong qua trlnh nay, ca hydro va oxy phn tu d duoc hoat hoa chuyn thanh dang cac ion H va O

, chung d dang kt hop voi nhau d tao thanh H2O va giai phong nhiu nang luong. Tomlai,banchtcuasuHHTBlaquatrlnhvnchuynhydrotucocht toioxydtaothanhnuoc.Thucchtlaquatrlnhvnchuyndintuvagiai phong nhiu nang luong cho co th su dung. 3. Co ch cua su HHTBNguoi ta co th chia chui HHTB ra lam 5 giai doan:Giaidoan1:chuynhydrotucocht(SH2)sangNAD(Nicotinamid Adenin Dinucleotid) nho enzym dehydrogenase co coenzym NAD: NADHH phn lon chuyn cho chui HHTB. Giaidoan2:NADHHchuynhydrochoIAD(hoacIlavin MononucleotidIMN)nhoemzymdehydrogenasecocoenzymIAD(Ilavin Adenin Dinucleotid IMN): Co truong hop IAD (IMN) nhn hydro truc tip tu co cht ma khng qua NAD. Giai doan 3: IADH2 chuyn hydro cho coenzym Q:

Giai doan 4: CoQH2 nha hydro va chuyn din tu dn h thng cytocrom (cyt), bat du tu cyt b cyt c1 cyt c cyt a cyt a3. Cyt a3 goi la cytocrom oxydase hay enzym h hp warburg: IADH2 CoQ IAD CoQH2

NADHH IAD NAD IADH2 SH2 NADS NADHH Ha sinh i cngPDI by http://www.ebook.edu.vn9

Giai doan 5: Cyt a3 chuyn din tu cho oxy phn tu, oxy phn tu nhn din tu tao thanh O2, O2 gan voi 2H tu CoQH2 tach ra d tao thanh phn tu nuoc: Thng thuong san phm cui cung cua chui HHTB la H2O nhung cung co truong hop xay ra phan ung sau:

H2O2 la mt cht dc di voi t bao, sau khi duoc hlnh thanh, cht nay se bi thuy phn ngay nho catalase:

Qua trlnh oxy hoa khu t bao duoc thuc hin qua cac chang vn chuyn H va din tu tu co cht voi oxy theo thu tu nhu trn goi la chui trung blnh. Nhung di khi, chui HHTB co th keo dai hoac rut ngan. iu nay phu thuc vao th nang oxy hoa khu cua tung co cht. Thi du: Khioxyhoapyruvathoaccetoglutarat,hydrotachraduocganvao lipothitamin pyrophosphat (LTPP) ri moi chuyn toi NAD, ta goi la chui dai: Co cht LTPP NAD IAD Cytocrom Oxy Khi oxy hoa acid beo, hydro tu co cht duoc chuyn thang toi IAD: Chui HHTB nay duoc goi la chui ngan. Co cht IAD Cytocrom Oxy H2O2H2O 1/2O2 2 cyt a3 Cu O2 2 cyt a3 Cu 2O

2H 2O

H2O 2 2 cyt a3 Cu 1/2 O2 2 cyt a3 Cu O2 2H O2 H2O CoQH2 2cyt b Ie3CoQ cyt b Ie2 2H 2cyt b Ie2 2cyt c1 Ie3 2cyt b Ie3 2cyt c1 Ie2

2cyt c1 Ie2 2cyt c Ie3 2cyt c1 Ie3 2cyt c Ie2

2cyt c Ie2 2cyt a Ie32cyt c Ie3 2cyt a Ie2

2cyt a Ie2 2cyt a3 Cu2 2cyt a Ie3 2cyt a3 Cu Ha sinh i cngPDI by http://www.ebook.edu.vn10 4. Cac qua trlnh oxy hoa khac Ngoaiquatrlnhtrn,trongcoth,mtschtcungthamgiavaoquatrlnh oxy hoa: Vitamin C: Glutathion: 2GSHGSSG 2H 2e 5. Cytocrom P450 Thuc con co tac dung di voi h thng enzym P450 monooxygenase cua ty th nhu qua trlnh hydrolase: Thuc dang H O2 2Ie 2HThuc dang OH H2O 2Ie Cytocrom P450 va phuc hop proteinsatluu huynh lin quan nhiu dn h thngcoenzymcuadehydrogenasetrongchuihhptbao.Quatrlnhlin quan th hin qua chu trlnh hydroxy hoa cua P450 ty th (Hlnh 2.3). SH2NAD+ FADH2CoQ2Fe++2Fe+++ 2Fe++ 2Fe+++2Cu+ 1/2O22e2e 2e 2e2e 2eCyt b Cyt c1Cyt cCyt a Cyta3S NADHH+FADCoQH2 2Fe+++ 2Fe++ 2Fe+++ 2Fe++2Cu++ O2-2H+ H2OHlnh 2.2: So d chui h hp t bao O CHOC O HOC CHOCH CH2OHDang khu O CO C O 2H 2eO C CHOCH CH2OH Dang oxy hoaHa sinh i cngPDI by http://www.ebook.edu.vn11 Suchuynhoathuccuahthngnaylabenzpyrene,anilin,morphin, bezphetamin. Nhiu tyhuc nhu phenobarbital co kha nang khoi dng hlnh thanh cytocrom P450 cua ty th. III. SU PHOSPHORIL OXY HOA 1. inh ngha Su phosphoryl hoa la sugan mt gc acid phosphoric (gc phosphat) vao mt phn tu cht huu co (RH):

Phan ung cn cung cp nang luong va nang luong duoc tich tru trong nhung lin kt phosphat. Su khu phosphoryl la su cat dut lin kt phosphat nho enzym phosphatase. Trong qua trlnh nay, nang luong duoc giai phong bang nang luong da tao thanh lin kt phosphat:

RPO3 H2 H2O RH H3PO4 phosphatase RH HOPO3H2RPO3H2 H2O phosphorylase (kinase) P450 , Ie3 O2 COHlnh 2.3 Vai tro P450 trong chui h hp t bao Co cht AH NADP NADPHH IADH2 IAD 2H H2O 2Ie2S23 2Ie2S22 P450AH , Ie3 P450AH , Ie2 P450AH , Ie2O2 P450AH , Ie2O2 e e NADPHCYT P450 REDUCTASE AOH Ha sinh i cngPDI by http://www.ebook.edu.vn12 Phosphorylhoalamttrongnhungphanungquantrongbcnhttrong chuyn hoa cac cht. No dong vai tro chu yu trong vic tich tru va vn chuyn nang luong.2. Cac loai lin kt phosphat Cancuvaonangluongtudoduocgiaiphongtuquatrlnhthuyphncatdut lin kt phosphat cua nhung hop cht phosphat huu co, nguoi ta chia cac loai lin kt phosphat ra lam hai loai: lin kt phosphat ngheo nang luong va lin kt phosphat giau nang luong. 2.1. Lin kt phosphat ngheo nang luong (ky hiu: ) Khithuyphncatdutlinktnay,chicotu10005000caloduocgiai phong: Lin kt este phosphat: Thi du nhu trong phn tu phosphoglyceraldehyd 2.2. Lin kt phosphat giau nang luong (ky hiu ~) Khithuyphncatdutlinktnay,nangluongduocgiaiphonglonhon 7000 calo. y la loai lin kt long leo, d bi pha vo. Mt s lin kt phosphat giau nang luong: Pyrophosphat: (Anhydrid phosphat)AdeninRibose (ATP) Acylphosphat: RCOO , tao thanh do gc acid cua cht huu co kt hop voi gc acid phosphoric. Thi du: trong 1, 3 diphosphoglycerat CHO CHOH CH2 O P H2O R OH HO PO3H2 R O PO3H2 (R O P )Ha sinh i cngPDI by http://www.ebook.edu.vn13 COOP I0 11.800 calo CHOH CH2 O P Enol phosphat R C OP ,, R

Lin kt nay duoc tao thanh do gc acid phosphoric kt hop voi nhom chuc enol cua cht huu co: Thi du: trong phosphoenol pyruvat: COOH C OP I0 14.800 caloCH2

Amid phosphat: do gc acid phosphoric kt hop voi nhom amin cua cht huu co: RNH Thi du: trong creatin phosphat NH P C NH I0 10.300 calo NH CH2COOH

Thiophosphat:dogcacidphosphorickthopvoinhomthucthiolcua cht huu co: RS Thi du: trong coenzym A pyrophosphat CoA - S ~ P ~ P Cht lin kt phosphat quan trong nht cua co th la ATP. ATP co mt lin ktestephosphatngheonangluongvahailinktpyrophosphatgiaunang luong. Ngoai cac lin kt giau nang luong, con cac lin kt giau nang luong khac nhu lin kt thioste. Thi du: trong acetyl coenzym A CH3 COS CoA Ha sinh i cngPDI by http://www.ebook.edu.vn14 3. Su phosphoryl oxy hoa va qua trlnh tich tru nang luong Trong qua trlnh oxy hoa khu t bao, din tu duoc vn chuyn tu h thng co thnangoxyhoakhuthpdnhthngcoth nang oxy hoa khu cao. Nu d chnhlchthnanggiuahaihthngchovanhnlonhon0,22voltthlnang luong giai phong ra du d tao mt lin kt giau nang luong trong ATP nho phan ungphosphorylhoaADP(cn7300calodtnghopmtphntuADPthanh ATP). Nu d chnh lch th nang giua hai h thng nho hon 0,22 volt, thl nang luong giai phong khng du d tao nn mt lin kt giau nang luong trong ATP va phn lon duoc toa ra duoi dang nhit. Vysu phosphorylhoaADPthanhATPdikemtheosuoxyhoakhunn goi la su phosphoryl oxy hoa. Trongcoth,ATPlunlunduoctnghopvathuyphn.Quatrlnhtng hopgiupcothtichtrunangluongvaquatrlnhthuyphndcungcpnang luong cho co th su dung.TrongchuiHHTB,3phntuATPduoctaothanhdosucungcpnang luong o 3 giai doan: Tu NAD dn IAD tich tru duoc 1 ATP. Tu cytocrom b dn cytocrom c1 tich tru duoc 1 ATP. Tu cytocrom (a a3) dn oxy tich tru duoc 1 ATP Qua trlnh phosphoryl oxy hoa xay ra o ty th. 4. iu hoa su phosphoryl oxy hoa Trong nhung diu kin sinh ly, su vn chuyn din tu gan lin voi qua trlnh phosphorylhoanghaladintusekhngduocvnchuynblnhthuongqua chuiHHTBtoioxynukhngcosuphosphorylhoaADPthanhATPxayra song song. Do do, diu kin cua su phosphoryl hoa la cn co cht, cac cht vn chuyn trunggiandintu,oxy,ADPvaphosphatvco,trongdomucADPlayut quyt dinh. Su diu hoa tc d qua trlnh phosphoryl oxy hoa boi muc ADP goi la qua trlnh diu hoa h hp. IV. CHU KY KREBS (Con goi la chu ky acid citric hay chu ky acid tricarboxylic). Ha sinh i cngPDI by http://www.ebook.edu.vn15 Cacchtglucid,lipid,protiddubithoaihoatrongtbaodnmtsan phmchunglagcacetylcoenzymA(vittatlaacetylCoA),cocngthucla CH3COSCoA. Cht nay duoc oxy hoa tip tuc dn san phm cui cung la CO2 va H2O. Qua trlnh nay duoc thuc hin o diu kin hiu khi trong ty th va duoc goi la chu trlnh Krebs. 1. Cac giai doan cua chu trlnh KrebsNguoi ta co th chia chu trlnh nay ra lam 8 giai doan. Giai doan 1: ngung tu acetyl CoA voi oxaloacetat tao thanh citrat: CH2 COOH H2OCH2 COOH CO COOH CH3 COSCoAHO C COOH HSCoA Citrat synthetase CH2 COOH Oxaloacetat Acetyl CoACitrat CoenzymAGiai doan 2: dng phn hoa citrat thanh isocitrat. Qua trlnh nay qua mt cht trung gian la cisaconitat va duoc xuc tac boi enzym aconitase: CH2 COOHCH2 COOHHO CH COOH H2O H2O HO C COOH C COOHCH COOH Aconitase Aconitase CH2 COOHCH2 COOH CH2 COOH Citrat CisaconitatIsocitrat Giaidoan3:oxyhoakhucarboxylisocitratthanhcetoglutarat:quatrlnh nayquamtchttrunggianlaoxalosuccinatvaduocenzymisocitrat dehydrogenase co coenzym NAD xuc tac. HO CH COOHCO COOHCO COOH NADNADHH CO2 CH COOH C COOH CH2

Isocitrat Isocitrat CH2 COOH dehydrogenaseCH2 COOHdehydrogenase CH2 COOH IsocitratOxalosuccinatcetoglutarat

Giai doan 4: Ha sinh i cngPDI by http://www.ebook.edu.vn16 CO COOH CHO CO SCoA CH2CH2 S S CH2 CH2 COOHCH2 COOHH COCH2 COOH a. cetoglytaricCH2 Succinyl CoA CH2COOH A. LIPOIC A. LIPOIC SS SSHH IAD IADH2 NADHH NAD CO COOH CoASH CO2 CH2 COOH CH2CH2

IAD IADH2 CH2 COOHCOS CoA

ceto glutarat NADHHNAD SuccinylCoA E : Phuc hop enzim ceto glutarat dehydrogenase E

Hlnh 2.4. Cac phan ung cua giai doan 4 Giai doan 5: tao succinat tu succinyl CoA: succinat thiokinase (succinylCoAsynthetase)xuctacvacnmtacidphosphoric.Nangluonggiaiphong duoi dang GTP, sau do chuyn thanh ATP. CH COOH H3PO4 H2O CoSHCH2 COOH CH2 COSCoACH2 COOHGDPGTP Succinat ATP ADP Succinat thiokinase

TTPTTP CO2 A.LIPOIC HSCoA Ha sinh i cngPDI by http://www.ebook.edu.vn17 Giaidoan6:oxyhoasuccinatthanhIumarat,enzymxuctac:succinat dehydrogenase co coezym IAD xuc tac. CH2 COOH IADIADH2CH COOH CH2 COOHSuccinat dehydrogenase CH COOH SuccinatIumarat

Giai doan 7: hydrat hoa Iumarat thanh malat, Iumarase xuc tac: CH COOH H2O CH2 COOH CH COOH Iumarat HO CH COOH Iumarat Malat -Giaidoan8:oxyhoamalatthanhoxaloacetat,malatdehydrogenaseco coenzymNADxuctac.PhanungdongvongchutrlnhKrebsvaphn tu oxaloacetat tip tuc tro lai ngung tu voi mt phn tu acetyl CoA moi. CH2 COOHNADNADHHCH2 COOH HO CH COOH Malat dehydrogenase CO COOH MalatOxaloacetat Ha sinh i cngPDI by http://www.ebook.edu.vn18 O CH3 C COOHACID BEO PYRYVAT

- OXY HO A PH C HP PYRUVAT DEHYDROGENASE O C - COOH CH2 - COOH OXALOACETAT

. CH2 - *COOH HO - C - COOH CH2 - COOH CITRAT

.CH2 - *COOH C - COOH CH - COOH CIS ACONITA

. CH2 -*COOH CH - COOH HO- CH - COOH ISOCITRAT

. CH2 - *COOH CH - COOH CO - COOH OXALOSUCCINAT HO - . CH - COOH . CH2 -*COOH L - MALAT H - .C - *COOH HOOC* -.C - H FUMARA .CH2 - *COOH CH2 - *COOH SUCCINAT .CH2 - *COOH CH2 CO~S - CoA SUCCINYL -CoA.CH2 - *COOH CH2 CO~ COOH - KETOGUTARAT MALAT DEHYDROGENASE IUMARASE ACONITASE ACONITASE ISOCITRAT DEHYDROGENASE ISOCITRAT DEHYDROGENASE SUCCINAT DEHYDROGENASE SUCCINAT THIOKINASE PHC HP -KETOGLUTARAT DEHYDROGENASEHlnh 2.5: So d chu trlnh acid citric NADH + H+NAD+ .CH3 - *CO~CoA ACETIL - CoA CoA.SH H2OH2OH2ONAD+ CO2 Mn++ NADH + H+ NAD+CoA.SH CO2 CoA.SH GTP Pi GDP FADH2 FAD H2O CO2 CoA.SH Fe++ Fe++ NAD+ NADH+H+ NADH + H+

2. Nang luong giai phong cua chu trlnh Krebs Kt qua cua chu trlnh la su oxy hoa toan gc acetyl, trong do co hai phan ung khu carboxyl loai carbon duoi dang CO2 va bn phan ung oxy hoa cung cp 4caphydro;4caphydronayduocchuyndnoxytrongchuiHHTBdtao thanh H2O va nang luong. Nang luong tich tru duoc cua chu trlnh Krebs gm: Ha sinh i cngPDI by http://www.ebook.edu.vn19 Giai doan 3:giai phong1NADHHdi vao chui HHTB duoc 3 ATP Giai doan 4: giai phong 1NADHHdi vao chui HHTB duoc 3 ATP Giai doan 6: giai phong 1 IADH2 di vao chuiHHTB duoc 2 ATP Giai doan 8: giai phong 1 NADHH di vao chui HHTB duoc 3 ATP Giai doan 5: giai phong 1 GTPduoc1 ATP Tng cng:12 ATP 3. Y ngha cua chu trlnh Krebs ChutrlnhKrebslagiaidoanthoaihoacuicungchungchocaccht glucid, lipid, protid xay ra trong diu kin hiu khi. Chutrlnhcungcpnhiucochtchohydro,cacchtnayduocchuyn dn chui HHTB d tao nang luong. Nang luong tao thanh cua chu trlnh, mt phn toa ra duoi dang nhit, mt phn tich tru lai duoi dang ATP cho co th su dung trong cac qua trlnh tng hop va sinh hoc khac cua co th. Ngoai ra chu trlnh Krebs con la noi cung cp cac san phm trung gian cn thitnhuoxaloacetat,acetoglutarat,succinylCoA,Iumarat...,cacsanphm naydungchocacphanungtnghophoacchuynhoanhutnghopglucid, acidamin, hemoglobin... Chu trlnh Krebs la vi tri ni lin voi cac qua trlnh chuyn hoa khac cua co th nn chu trlnh tro thanh vi tri trung tm diu hoa chuyn hoa cac cht. Chu trlnh Krebs co mi lin quan voi hai qua trlnh: HHTB va phosphoryl hoa: chu trlnh Krebs cung cp co cht cho hydro cho chui HHTB, trong chui HHTBchungbioxyhoadchonangluong,nangluongtaothanhduoc phosphoryl hoa d tich tru nang luong duoi dang ATP. 4. Chu trlnh acid glyoxylic Mt s vi khun va nm mc con co qua trlnh chuyn hoa trung gian cua cachopchtcarbonboimtschutrlnhhoikhacchutrlnhKrebs,goilachu trlnh acid glyoxylic. Tom tat so d nhu sau (Hlnh 2.5). Trong chu trlnh glyoxylic co hai dac tinh la: Acidisocitricduocphntachthanhacidsuccinicvaacidglyoxylicnho enzym isocitrat lyase. CH2COOH CH COOH CHCHCOOH acid isocitricacid succinic acid glyoxylic CH2COOH CHO CH2COOH COOH Ha sinh i cngPDI by http://www.ebook.edu.vn20 AcetylCo AcetylCoA Hlnh 2.6.Chu trlnh acid glyoxylic A. CitricA. Oxaloacetic A. Isocitric A. Malic A.Glyoxylic AcidglyoxylicduockthopvoiacetylCoAdtaothanhacidmalic duoc xuc tac boi malat synthetase. Chungtacothnhnthyrangchutrlnhglyoxylicsudung2phntu acetylCoA.Chutrlnhnaycovaitroquantrongtrongquatrlnhchuynhoa acid beo thanh glucid. COOH CHO CHOH COOHCH2 COOH Acid glyoxylic acid malic CH3 CO SCoAH2O CoASH A. Succinic Ha sinh i cngPDI by http://www.ebook.edu.vn21 Bi 3: HOA HOC VA CHUYN HOA GLUCID Muc tiu: 1.Nu nh ngha v vai tr ca glucid. 2.Vit c cc dng ng phn ca glucoz. 3. Nu c ngun gc, cu to, tnh cht ca cc cht l dn xut ca. monosaccaric,disaccaric v polysaccaric. 4. Nu c cc qu trnh chuyn ha glucoz PHN 1 HOA HOC GLUCID 1. AI CUONG 1.1.inhngha:Glucidlamtchthuuco,comthoacnhiu monosaccarid (hoac dn xut cua monosaccarid). Monosaccarid duoc cu tao boi cac nguyn t C, H, O, ngoai ra con co chua cac nguyn t khac trong cac glucid tap. 1.2. Phn loai: gm 3 loai. Monosaccarid(Osehaydonduong)ladonvicutaocua glucid,khngbithuyphn.Vidu:Glucose,Iructose,galactose, ribose... Oligosaccarid: phn tu gm tu 2 dn 10 monosaccarid, ni voi nhau bang lin kt glucosid. Quan trong nht la cac Disaccarid. Vi du: Saccarose, maltose, lactose. Polysaccarid: gm nhiu monosaccarid va duoc chia lam 2 loai: *Polysaccaridthun:gmnhiumonosaccaridcungloaini voi nhau bang lin kt glucosid. Vi du: tinh bt, glycogen, cellulose. *Polysaccaridtap:gmcacmonosaccaridthucnhungloai khacnhau,dnxutcuacacmonosaccaridvamtschtkha c.Vi du: glycolipid, Glycoprotein... 1.3. Vai tro cua glucid 1.3.1. O dng vt: Glucid chim 20 trong luong kh cua co th. Co vai tro: Chu yu la cung cp nang luong cho co th. Ngoai ra con tham gia cu tao t bao va cac thanh phn trong co th nhu acid nucleic, glycoprotein, glycolipid. 1.3.2.Othucvt:Glucidchim8090trongluongkh,lathanh phn chinh cua m nng do va m du tru. Ha sinh i cngPDI by http://www.ebook.edu.vn22 2. MONOSACCARID 2.1. Cu tao va danh phap 2.1.1. Cu tao: Monosaccarid la nhung polyalcol, co th la ahdehydalcol hoac cetonalcol, trong do mt carbon thuc nhom carbonyl, con ttcacaccarbonkhacdulinktvoinhomhydroxyl(OH) Monosaccaridconhomaldehydduocgoilaaldose,conhomceton duoc goi la cetose. HCH2OH C OC O (CHOH)n (CHOH)n CH2OHCH2OH AldehydalcolCetonalcol (aldose) (cetose) n: S nhom alcol bc 2. 2.1.2. Danh phap Tn goi cua monosaccarid duoc ghep vn ose sau chu s C tuong ung bangtingHylapvatipdungulaaldohoaccetodbiuthichuc aldehyd hoac ceton. Vi du: Aldotriose: chuc aldehyd, co 3C. Aldotetrose: chuc aldehyd, co 4C. Cetopentose: chuc ceton, co 5C. Trong co th monosaccarid don gian nht la triose (3C) va lon nht la heptose (7C). 2.2. Mt s monosaccarid quan trong trong co th 2.2.1. Pentose:(5C) mt s pentose quan trong: Ribose: CHO (CHOH)3 CH2OHCng thuc thangCng thuc vong Hlnh 2.1 Cu tao RiboIuranose (dang ) Deoxyribose : OHHOCH2 HHHOH OH Ha sinh i cngPDI by http://www.ebook.edu.vn23 CHO CH2 CH(OH)2 CH2OH D. Deoxyribose D DeoxyriboIuranose Hlnh 3.1 Cu tao DeoxyriboIuranose (dang ) Ribose va Deoxyribose nay tham gia cu tao acid nucleic. 2.2.2. Hexose (6C). Mt s hexose quan trong: Glucose: COHC OH HC H OHC OH HC OH HCH2OH Trong co th glucose co trong t bao,dich,chtchuynhoachu yu cua glucid. Glucose ph bin trong tu nhin, nhiu trong nho. Glucoselathanhphncua glucidkhacnhusaccarose, glycogen, tinh bt... CH2OHOHH HOHOHH OH H HOHHOCH2 H HHOH H Ha sinh i cngPDI by http://www.ebook.edu.vn24 Galactose Iructose CH2OHC OC H OHC OH HC OH HCH2OH

DIructoseDI ructoIuranoseHlnh 3.2. Cu taoD Glucose, D Galactose va DIrutose Trong co th dng vt, Iructose la sanphmchuynhoatrunggian cua glucid. Trong thuc vt: Iructose co nhiu trong hoa qua. Co trong mt ong, tham gia thanh phn cu tao cua saccarose. 2.3. Mt s tinh cht cua monosaccarid 2.3.1. Tinh khu (bi oxy hoa)Trong phn tu monosaccarid co nhom chuc nang aldehyd loac ceton nn co tinh khu. Monosaccaridse khu mui kim loai giai phong oxyd kim loai co hoa tri thp hon, con monosaccarid bi oxyd hoa thanh acid. Phan ung oxy hoa tai C1 cua carbonyl trong phn tu aldose tao acid aldonic (glutamat). Phan ung oxy hoa C6 cua glucose tao acid uronic (glucuronat). COHC OH HC H OHCC OH HCH2OHHO H D Galactose DGalactopyranose Trong co th dng vt, galactose tham gia cu tao lipid tap, lactose O thuc vt co trong thach, gm. CH2OH CH2OH OH HHO OHH CH2OH OH H HOH OHHOH H Ha sinh i cngPDI by http://www.ebook.edu.vn25 Hlnh 3.3. San phm oxy hoa glucose PhanungthuongdunglaIehling(thucthucoionCuduoi dang Cu(OH)2) Phan ung Iehling dung d dinh tinh va dinh luong duong trong nuoc tiu. 2.3.2. Tinh oxy hoa (bi khu) Cac monosaccarid bi khu tao thanh polyalcol. CHO CH2OH RR Vi du: 2.3.3. Phan ung tao IurIural Duoitacdungcuaacidvcodmdac(HCl,H2SO4)cac monosaccaridbikhunuoctaothanhIurIuralhoacchuynhoacht IurIural. 2C uO H Cu2O H2O Tua dotoR C HO 2Cu(O H)2COOH2CuOH H2O R +2H GlucoseSorbitol Mannose Mannitol Irutose Sorbitol Ribose Ribitol 2H CO H OH C H 2 O H O H HO HH OO

COHOHOHOHH OHHHCO

OD gluconet DglucuronatHa sinh i cngPDI by http://www.ebook.edu.vn26 IurIuralphanungvoicacphenol(naphtol,orcin,resorcin...) cho nhung phm vt co mau dac bit. Phan ung dung d nhn dinh cac loai monosaccarid khac nhau. 2.3.4.Phan ung enzym (glucose oxydase) DGlucose O2

Glucose oxydaseDGluconat H2OCh tma unu.Pha nu ngduo cdu ngd dinhtinhva dinh luo ng glucose trong ma u vanuo c ti u. 2.3.5. Phan ung tao osamin: Cac monosaccarid lin kt voi cac nhom NH2 taoosaminehoacNacetylosaminthamgiacutaocac polysaccaridtap.Viduglucosamin,galactosamin,NAcetyl glucosamin, N Acetyl Galactosamin... 3. OLIGOSACCARID Phntugmtu2dn10monosaccaridnivoinhaubanglin kt glucosid. Quan trong nht la cac Disaccarid. 3.1.Disaccarid:Trongphntugm2monosaccaridnivoinhau bang lin kt glucosid. Cac disaccarid quan trong. 3.1.1. SaccaroseCu tao gm 2 phn tu D glucose va D Iructose,cunioxygiuaCthunht mang chuc aldehyd cua glucose va C thu 2 mang chuc ceton cua Iructose. Tn hoa hoc cua saccarose: 1, 2.D glucosidoD Iructose, khng co tinh khu do khng co nhom (OH) ban acetal tu do. Saccarose co nhiu trong mia, cu cai duong. 3.1.2. Lactose CutaogmDgalactosevaglucose, cuoxyniCthunhtmangnhom aldehyd cua galactose voi C thu 4 mang nhomalcolcuaglucose.Tnhoahoc cualactosela Ha sinh i cngPDI by http://www.ebook.edu.vn27 14 D galactosido. D glucose. Lactose cotinhkhudo vn con nhom (OH) ban acetal tu do. Co nhiu trong sua. 3.1.3. Maltose Cutaodo2phntuDglucose,cu oxy ni C thu nht mang nhom aldehyd cuaglucosenayvoiCthutumang nhom alcol cua glucose kia. Tnhoahoc:14Dglucosido D glucose. Maltose co tinh khu do con mang nhom (OH) ban acetal tu do. Co nhiutrongmmlua,machnhalasan phm thuy phn cua tinh bt, glycogen.Hlnh 3.4. Cu tao cua cac Disaccarid din hlnh 3.2. Trisaccarid va tetrasaccarid GmRaIinose(trisaccarid)cotrongcucaiduongvaStakyose (tetrasaccarid) co trong du tuong va nhiu thuc vt khac. 4. POLYSACCARID (A UONG) Chia lam 2 nhom: polysaccarid thun va polysaccarid tap. 4.1.Polysaccaridthun(Homopolysaccarilglycol):donhiu monosaccarid cung loai tao nn. 4.1.1. Tinh bt 4.1.1.1Cutao:Gmco2phncocutaovatinhchtkhacnhau; Amylose va amylopectin. -Amylose: H CH2OH

CH OHH HOH OH HOH HOHCH2OH H H OHHOHH HCH2OH HH OHHOHHOH CH2OH H HOH OHH OH H H H H HHa sinh i cngPDI by http://www.ebook.edu.vn28 Chim1225tinhbt.Cocutaogm200dnhangnghln gcDglucosenivoinhaubanglinkt14glucosidtaothanh mach thang khng phn nhanh. Trong dung dich co dang xoan. Amylopectin: Hlnh 3.5. Cu tao Amilose va Amylopectin cua tinh bt Chim7585tinhbt.CutaogmnhiugcDglucoseni voinhaubanglinkt14va16glucosid.Caclinkt14 glucosidtaothanhmachthangvalinkt16glucosidtaothanh mach nhanh, mi mach nhanh chua tu 2025 gc glucose. 4.1.1.2.Tinh cht Tinh bt co tinh cht: Khngtantrongnuoclanhvadungmihuuco,tantrong nuoc nong tao thanh dung dich keo goi la h tinh bt. Cho mau xanh tim voi Iod. Tinhbtbithuyphnboiacidvanhitdsihoacenzym amylase tao thanh cac san phm trung gian la dextrin chomaukhacu khng khu Lin kt u khuCH2OH Mach nhanh Mach bn H 6CH2 HOH HOH H Lin k tHHOH HOH H H H o Ha sinh i cngPDI by http://www.ebook.edu.vn29 nhauvoi Iod,cuicung cho maltose ri glucose khng cho mau voi Iod. Tinh bt khng th hin tinh cht khu mac du con nhom (OH) ban acetal tu do nhung vl nhom nay qua it so voi phn tu tinh bt qua lon. Tinhbtcootrongngucc,cacloaicu,lathucanchinhcua dng vt. 4.1.2. Glucogen: cu tao ging Amylopectin, nhung phn nhanh nhiu hon va nhanh ngan hon, mi nhanh gm khoang 12 gc glucose.Tinh cht: Khng tan trong alcol ethylic. Cho voi Iod mau nu do. La cht keo ua nuoc. Khibithuyphnglycogentaothanhdextrinrimaltose, glucose. Glycogen la cht du tru glucid cua dng vt, nhiu nht o gan va co. 4.1.3. Cellulose: La thanh phn chu yu cua m nng do thuc vt. Cu tao gm nhiu gc D glucose ni voi nhau boi lin kt 14 glucosid, khng phn nhanh. Hlnh 3.6. Cu tao cua Cellulose

Tinh cht: Cellulosekhngtantrongnuoc, tantrongdungdichSchweitzer (oxyddngnhitrongdungdich amoniac). Khng cho mau voi Iod. Thuyphnvoiacidvaenzym cellulosechocellobioseri glucose. CH2OH CH2OH CH2OHOH OH OH OH OHOH Ha sinh i cngPDI by http://www.ebook.edu.vn30 Enzymcellulosekhngcoongtiuhoanguoinncellulose khngcogiatridinhduongdivoinguoi,cellulosetlmthytrong ng tiu hoa tru, bo, mi... 4.1.4. Dextran La cht du tru cua con men, vi khun. Cutaogmnhiuglucosenivoinhauboilinkt16 glucosid tao thanh mach thang, phn nhanh o cac lin kt 12 hoac 13, 14 glucosid. Trong luong phn tu Dextran co d nhot cao, dung lam cht thay th huyt tuong trong y hoc. 4.2. Polysaccarid tap4.2.1.Peptidoglycan:Lanhungpolysaccaridmachthangcutaonn thanh t bao vi khun, gm cac chui disaccarit lap lai: acid Nacetyl muramicvaNacetylglucosaminMurNac(14)GlcNacdan cheo nhau bang nhung chui peptid ngan (hlnh 3.7). Hlnh3.7.PeptidoglycancuathanhtbaoVikhun staphylococcus aureus 4.2.2.Glycosaminoglycan(mucopolysaccarid)lanhungglucidphuc tapdactrungboicacchuidisaccaridlaplaigmcoduongaminva acid uronic. Cac glycosaminoglycan quan trong la: HOHOHH CO NHHHHCH2OCH3HOHOHH CO NHHHHCH2OCH3OnOCH3CHCO L AlaIsogluLysAla(GLy)sDLD(Gly)sOHa sinh i cngPDI by http://www.ebook.edu.vn31 Acidhyaluronic:cutaoboicac chuidisaccaridlaplaigmacidDglucuronicvaNacetylglucosamin nivoinhaubanglinkt13glucosid.Trongluongphntutrn mttriu,taothanhdungdichtrong nhotcotacdunglamtronhoatdich cuacackhopvathuytinhdichcua mat,giupchosuvndngvangan chan su xm nhp cua nhiu cht dc di voi co th. Acid hyaluronic con la thanh phn chinh cua matrix ngoai t bao, cua sun va gn lam tang tinh co dancuacactchucnay.Enzym hyaluronidasexuctacsuthuyphn linktglycosidcuahyaluronatva cohoattinhmanhtrongtinhdich, noc ran va mt s vi khun. CondroitinsulIat:lamt glycosaminoglycanacidgmacidglucuronicvaNacetylgalactosaminsulIat|GlcUA(13)NacSO4]n.Noconhiu trongtchucsun,tchuclinkt(gn,da,vantimvathanhdng mach). Heparin: Cu tao boi nhung chui disaccarid lap lai gm acid iduronicgansulIatvaglucosaminsulIatnivoinhaubanglinkt 14glucosid.Nonganchanchuynhoaprothrombinthanhtrombin, do do co tac dung chng dng mau. Heparinconcotacdunggiaiphonglipoproteinasetutchuc vaohuyttuong.Enzymnayxuctacsuphnhuycacphuchop lipoprotein trong qua trlnh vn chuyn va chuyn hoa lipid. 4.2.3. Glycoprotein va glycolipid. Ha sinh i cngPDI by http://www.ebook.edu.vn32 Mangtbaodngvtchuakhoang5glucidoduoidang glycoproteinvaglycolipid.olanhunghopchttrongdonhiu proteinvamtslipidcuamangtbaoganvoicacoligosaccarid bang lin kt cng tri. Glycoprotein (mucoprotein) tlm thy trong cac dich, m, mang t bao. Nhiu hormone co ban cht la glycoprotein nhu LH, ISH,.. nhiu glycoprotein co vai tro quan trong o mang t bao nhu KN nhom mau A, B, O. Glycolipidvalipopolysaccarid:dulathanhphncutaocua mang t baoPhn 2 CHUYN HOA GLUCID 1. AI CUONG Chuyn hoa glucid la mt trong nhung qua trlnh chuyn hoa quan trong cua co th sng, chu yu cung cp nang luong cho t bao hoat dng. Glucid dam bao tu 6070 nhu cu nang luong cua nguoi (tuc la chim 6070 s calo cua khu phn an). Glucid la thanh phn cu tao cua mt s cht quan trong v mat sinh hocnhuacidnucleic,glycoprotein,glycolypid,mtsenzym,nhungchtnay thamgiacutaotbaocuacacmvathamgiavaonhiu qua trlnh hoat dng OOOoSiaoGalNAcNHCOCH3oGaloooFucORNhom OOoGalNAcNHCOCH3ORoooFucoGaloGalNAcNHCOCH3oSiaOOONhom AOORoooFucoGaloGalNAcNHCOCH3oSiaOOOoGalNhom BHa sinh i cngPDI by http://www.ebook.edu.vn33 cuacoth(yutdngmau,mangsinhhoc,thanhphntrunggiancuanhom mau,globulinmindich,hormone...).chuynhoaglucidcontaoranhiusan phmchuynhoatrunggianquantrong,linquanvoisuchuynhoacaccht khac trong co th nhu chuyn hoa lipid, acid amin va acid nucleic.2. SU TIU HOA, HP THU VA NHU CU GLUCID 2.1. Su tiu hoa Quatrlnhtiuhoaglucidtuthucan(tinhbt,glycogen,disaccarid...)nho su thuy phn cua cac enzym h tiu hoa : Amylase cua nuoc bot, dich tuy se thuy phn cac lin kt 14 glucosid cuaphntutinhbt,glycogentaothanhsanphmcuaglucidladisaccarid, monosaccarid. Disaccaridasecomatomangngoaitbaothanhrut,thuyphncac disaccaridtaothanhcacmonosaccarid.Sanphmthuyphncuicungcua glucidlacacmonosaccaridchuyulacacglucosevamtsitlaIructose, galactose... 2.2. Su hp thu glucid San phm thuy phn glucid thuc an la cac monosaccarid duoc hp thu qua t bao nim mac rut thuong xay ra o phn du rut non, qua tnh mach cua dn gan.Ogan,mtphnglucoseduocgansudungmtphndutruduoidang glycogen, phn con lai qua tnh mach cua trn gan vao mau d cung cp glucose cho co, thn kinh, hng c u va cac m khac su dung. Su hp thu cac monosaccarid xay ra o phn du rut non voi tc d khac nhauphuthucvaocutaovanngdcuachung,theothutula:galactose, glucose, Iructose, mannose, pentose. Su hp thu nay xay ra theo hai co ch : Co ch khuch tan tu noi co nng d cao dn noi co nng d thp, xay ra voi mt s monosaccarid nhu arabinose, mannose, Iructose. Cochvnchuyntichcucnhosuphosphorylhoaxayravoimts monosaccaridnhuglucose,galactose,cacmonosaccaridduocvnchuynqua mang t bao thanh rut voi tc d nhanh va khng phu thuc voi gradient nng d cua chung giua t bao va dich long rut theo nhu c u co th. 2.3. Nhu cu. Onguoitruongthanh,nhucutithiuhangngay180gglucosedcung cp nang luong cho cac t bao, nhu h thng thn kinh cn 144g glucose trong 24gio,hngcu36gglucosetrong24gio.Nhucuglucosecuacothduoc Ha sinh i cngPDI by http://www.ebook.edu.vn34 cungcptuthucanhoactucacquatrlnhchuynhoakhaccuacothddam bao duy trl nng d glucose mau : 60100mg/dl. 3. CHUYN HOA GLYCOGEN 3.1. Thoai hoa glycogen thanh glucose Trong co th nguoi va dng vt, glycogen du tru chu yu o gan, co. Qua trlnhthoaihoaglycogentrongtbaotaoraglucose6phosphat,ricothtip tucthoaihoahoantoandcungcpnangluongchotbao hoat dng. Tai gan glucose 6 phosphat co th duoc giai phong duoi dang glucose tu do vao mau d cung cp cho cac t bao 3.1.1. Giai doan thuy phn mach thang cua glycogen. EnzymglycogenphosphorylasecatgcGodukhngkhucuamach thang glycogen do la phan ung thuy phn lin kt 14 glucosid, dng thoi co su thamgiacuaphosphatevcotaothanhglucose1phosphatvachuiglycogen ngan di 1 phn tu glucose.Quatrlnhlaplainhiulnchodnkhimachconkhoang4gcGthl dung lai, san phm con lai la dextrin gioi han.

O OCH2OH CH2OHOHOHOHOHOHOOCH2OHOHOHO Glycogen(Glucose)nu khng khu(Glucose)nGlycogen OOHOHCH2OHOOHOHCH2OHO OCH2OHOHOHOPiGlycogen phosphorylaseP OOO-1--+ Hlnh 3.8. Phan ung xuc tac cua glycogen phosphorylase tao G1P va glycogen ngan hon 1 glucose. 3.1.2. Giai doan cat mach nhanh cua glycogen. Bn gc G duoc loai ra theo qua trlnh gm 2 buoc nho xuc tac cua enz cat nhanh. Enz nay co 2 chuc nang: Chuc nang vn chuyn: Tac dung cat oligosac gm 3 gc G du mach cua dextrn gioi han va chuyn chung sang gan vao du khng khu cua Ha sinh i cngPDI by http://www.ebook.edu.vn35 mach k bn bang lin kt 14 glucosid. Vung chuc nang nay goi la amylo1.4 1.4 trans glucosidase (hoac amylo1.6 1.4 trans glucosidase)Chuc nang cat nhanh: Tac dung cat gc G con lai tai dim nhanh bang cachthuyphnLK16glucosidvagiaiphongGduoidangtudo. Chuc nang nay goi la amylo 1.6 glucosidase Phanungcatnhanhchophepenzphosphorylasetiptuchoatdngd thoai hoa hoan toan phn tu glycogen. Nhu vy san phm cua 2 giai doan thoai hoa glycogen la G1P (chim 93) va glucose tu do ( 7). Lin kt 16 glucosid u khng khu (1) Glycogen phosphorylase(2) Hoat tinh transIerase cuaenz cat nhanhHoat tinh 16 glucosidasecua enz cat nhanh Chui glycan ( 14) khng nhanh tip tuc bi thuy phn boi GP Hlnh 3.9. Hai giai doan thoai hoa glycogen3.1.3. Giai doan bin di glucose 1 phosphat thanh G6POcactchucG1PchuynthanhG6Pduoisuxuctaccuaenzym phosphoglucomutase 3.1.4.Chuynglucose6phosphatthanhglucose:Glucose1phosphatchuyn thanh glucose 6 phosphat duoi su xuc tac cua enzym phosphoglucomutase CH2OH O-P phosphoglucomutaseCH2O-P glucose 6- phosphat Glucose-1-phosphat Ha sinh i cngPDI by http://www.ebook.edu.vn36 Glucose 6P H2OGlucose H2O Qua trlnh xay ra chu yu o gan, vl gan co enzym glucose 6 phosphatase giai phongglucosetudovaomau,diuhoaduongmautrongquatrlnhhoatdng cua co th. Co va nao giuglucose 6 phosphat d lam cht dt cn cho su tng hop ATP. Su thoai hoa glycogen o t bao cua t chuc noi chung nham muc dich cung cpglucose 6 phosphat cho t bao su dung. 3.2. Tng hop glycogen tu glucose Nguyn liu d tng hop glycogen cua t bao la glucose.3.2.1. Chuyn glucose thanh glucose 6 phosphat Glucosetudoomautunhoansaukhithmquamangtbao,duoc phophoryl hoa thanh glucose 6 phosphat duoi su xuc tac cua enzym hexokinase hoac glucokinase (dac hiu voi glucose). 3.2.2. Chuyn glucose 6 phosphat thanh Glucose 1P.

Glucose 6P glucose 1P Glucose 1P co cht truc tip cua qua trlnh tng hop glycogen. glucose 6 phosphatase Glucokinase hexokinase CH2OH CH2OP ADP ATP Mg glucose 6 phosphatglucose CH2OP CH2OH OP phosphoglucomutaseHa sinh i cngPDI by http://www.ebook.edu.vn37 3.2.3. Tng hop mach thang cua phn tu glycogen. G1P duoc tao thanh se phan ung voi Uridin triphosphat (UTP) tao thanh 1 nucleotid hoat dng la uridin diphosphoglucose (UDPG). P/u duoc xuc tac boi enz UDPGpyrophosphorylase: G1PUTP UDPGlucose PPi Duoitacdungcuaenzglycogensynthetase,gcglucosylhoathoatrong UDPG duoc chuyn dn gan vao du khng khu (C4) cua phn tu glycogen co san(hlnhthanhlinkt14glucosid).Quatrlnhlapdilaplaivamachthang glycogen cu dai dn. 3.2.4. T ng ho p ma ch nha nh cu a phn tuglycogen Khima chglycogenduo cke oda i611g cGthlenzga nnha nh amylo1,41,6)transglucosidasese ca tdoa nd ucu ama chtha ngco it nh t6g cGva chuy nd nga nva oOHcu aC6cu aglucosecu nghoa c kha c chu i, hlnh tha nh lin k t 16 glucosid ta o ma ch nha nh. Qua trlnhna yla pla iva s luo ngnha nhtangd nchod nkhiptuglycogen coc u tru c phuho p vo i nhu c u cu a tba o. O CH2OH O PP UridinCH2OHOCH2OHOCH2OH OO ROORUridin PP Glysynthetase UDPGGlycogen (n gc glucose) UDP Glycogen (n1 l )Ha sinh i cngPDI by http://www.ebook.edu.vn38 Gly synthetase Amylo TransIerase 4. CHUY N HO AGLUCOSE 4.1. Thoa i ho a glucose: Theo 2 con duo ng chinh: 4.1.1.uo ng phn theo con duo ng hexosediphosphat4.1.1.1. Thoa i ho a cu a glucose d n pyruvat Glucose duo c phosphoryl ho a tha nh glucose 6 phosphat duo i suxu c ta c cua enzym hexokinase, glucokinase voi su tham gia cua mt phn tu ATP va Mg. Sau doglucose 6 phosphat bi phosphoryl ho a l n hai ta o hexosediphosphat r i hexosediphosphat bi ca t di tha nh 2 phn tutriosephosphat, ti p theo lasuoxy ho a triosephosphat d n acid pyruvic vaacid lactic. Ca c pha n u ng cu a quatrlnh duo ng phn d u xa y ra oba o tuong cu a tba o. Ha sinh i cngPDI by http://www.ebook.edu.vn39 Hlnh 3.10. So d qua trlnh duong phn theo con duong HexodiphosphatHa sinh i cngPDI by http://www.ebook.edu.vn40 4.1.1.2. Chuyn hoa cua pyruvat * Trong diu kin ym khi: t chuc khng duoc cung cp du oxy, pyruvat se chuyn thanhlactat duoi tac dung cua enzym lactat dehydrogenase (LDH) qua trlnh nay xay ra chu yu o t chuc co, xuong.

C OCOOCH3H

CHOHCOOCH3HNADHH NADL LactatLDH Su tao thanh ethanol (ln men ruou): Nhiu nm men va cac VSV khac thuong bin glucose thanh ethanol hon la thanh lactat., phan ung qua 2 buoc:

C OCOOCH3H

C OCH3HCO2

HC OHCH3HH NADHH NADPyruvat decarboxylase Alcol dehydrogenasePyruvat Acetaldehyd Ethanol *Trong diu kin hiu khi: khitbaocuatchucduoccungcpduoxy, pyruvatseduocchuynvaotrongtyth. O do no bi khu carboxyl oxy hoa tao acetyl coenzym A va duoc dt chay hoan toan trong chu trlnh Krebs. Phan ung khu carboxyl oxy hoa cua pyruvat la mt chui phan ung duoc xuc tac boi mt phuc hop da enzym la pyruvat dehydrogenase, phuc hop nay co su tham gia cua cac coenzym : Thiamin pyrophosphat (TPP) ; acid lipoic (dang khu va dang oxy hoa);coenzymA(CoASH);NAD(Nicotinamidadenindinucleotid);IAD (Ilavin adenin dinucleotid). Tom tat phan ung : HSCoAMgCO2TPPCH3 COCOOH CH3COSCoA Pyruvat Lipoat Acetyl Coenzym A IAD, NAD IADH2,NADH2 Phuc hop Enzym pyruvat dehydrogenase Ha sinh i cngPDI by http://www.ebook.edu.vn41 Acetyl CoA duoc tao thanh se di vao chu trlnh Krebs thoai hoa dn CO2, H2O va nang luong ATP. 4.1.1.3.Nang luong cua su thoai hoa glucose theo con duong phn * Trong diu kin ym khi Tu glucose dn lactat tao ra nang luong nhu sau : Glucose glucose 6 phosphat : 1 ATP I 6 I 1.6 di 1 ATP 2.1.3. diphosphoglycerat 2.3 phosphoglycerat: 2ATP 2 Phosphoenol pyruvat 2 pyruvat : 2ATP Tng cng: 4ATP2 ATP2ATP Con 2NADHH duoc tao thanh do phosphoryl oxy hoa phosphoglycerat da bi su dung d chuyn pyruvat thanh lactat. Tu glycogen : do G6 duoc tao nn do thoai hoa glycogen cua t bao nn khng co su tiu tn 1ATP (tu glucose G6).Tng s nang luong tao ra : 4ATP1ATP 3ATP *Trong diu kin hiu khi Tu glucose : mt phn tu glucose thoai hoa hoan toan se cho : Tuglucosedn2pyruvatduoc2ATPva2NADHH(2NADHHvao chui h hp t bao se cho 6 ATP) : cho 8ATP. Tu2pyruvatdn2acetylCoAduoc2NADHHvaochuihhpt bao se cho 6ATP) : cho 6 ATP. Oxy hoa 2 acetyl CoA trong chu trlnh Krebs cho 24 ATP. Tng cng :38 ATP. TuGlycogen:cho39ATP.(Khngmt1ATPtuglucoseglucose6 phosphat) 4.1.1.5.Y nghaQuatrlnhthoaihoaglucosenhamcungcpnangluongchotbaohoat dng, cac san phm trung gian cho nhiu qua trlnh chuyn hoa khac cua co th. Su thoai hoa glucose theo con duong duong phn ym khi cung co y ngha quan Ha sinh i cngPDI by http://www.ebook.edu.vn42 trongvphuongdinnangluong,macdutaoraduocitATP.Matkhacsan phmthuduoclalactatseduoccothsudunglaidtaitaoglucosechoqua trlnh thoai hoa tip theo. 4.1.2.Qua trlnhduo ngphntheoconduo nghexosemonophosphat(chu trlnh pentose phosphat) Suoxyhoatheoconduongnayxayraocactchucsongsongvoicon duonghexosediphosphat nhung chim ty l thp (710). Tuy nhin o mt s t bao va t chuc nhu hng cu, gan, tuyn sua trong thoi ky hoat dng, t chuc mo.... su thoaihoaglucosetheoconduongnaylaichimuuth.Cacphanungcuacon duongthoaihoanayxayraobaotuongcuatbaovlca cenzymxuctacphan ung nam o phn bao tuong cua t bao). Chu trlnh pentose phosphat duoc trlnh bay nhu mt chu trlnh kin trong do cu ba phn tu G6 di vao se tao ba phn tu CO2 va ba phn tu pentose phosphat, tip theo la mt chui phan ung bin di, d ba phn tu pentose trn tao thanh hai phn tuG6 va mtphn tu phosphoglyceraldehyd. Triose nay hoac se thoai hoa tip tuc theo con duong duong phn tao pyruvat, hoac sau khi dng phn hoa thanh phosphodioxyaceton (PDA) thl 1 PGA (phosphoglyceraldehyd) se kt hopvoi mt phn tu PDA d tao thanh Iructose 16 dip , sau do la phan ungthuyphngcphosphatdtaothanhIructose6.Phntunaydngphn hoa thanh G6va tip tuc di vao chu trlnh pentose phosphat. Mat khac tu san phm Iructose 16 di cung co th di vao qua trlnh thoai hoa theo con duong hexose diphosphat. Ha sinh i cngPDI by http://www.ebook.edu.vn43 Hlnh 3.11. So d chu trlnh Pentose Ha sinh i cngPDI by http://www.ebook.edu.vn44 Phan ung tng quat chu trlnh:

Y ngha chu trlnh pentose phosphat: Quan trong nht la cung cp NADPHH. NADPHHlacoenzymdachiucuanhiuphanungcncungcp hydro nhu tng hop acid beo, cholesterol, cac hormon steroid. NADPHH giupchophanungchuynglutathiondangoxyhoasang dangkhu,glutathiondangkhucovaitrophnhuyH2O2,tranhudongH2O2. Phan ung nay rt quan trong o t bao hng cu, vl su u dong H2O2 se gy ra su oxy hoa mang t bao, pha vo mang t bao hng cu dn dn su huyt tan.

Chu trlnh pentose phosphatcon cung cp cac pentose cho qua trlnh tng hop acid nucleic. 4.2. Tng hop glucose. Tnghopglucosetunhungsanphmchuynhoatrunggianpyruvat, lactat, acid amin... qua trlnh nay con goi la su tn tao duong. 4.2.1.Tng hop glucose tu pyruvat. Quatrlnhtntaoglucosetupyruvatvhlnhthucduocsapxptheothutu gnnhumtquatrlnhduongphndaonguoc,trongdoco3giaidoankhng thun nghich3G6 6 NADP 3 H2O2G6 Pglyceraldehyd 3 CO2 6NADPHH

6G612NADP 6H2O 5G612NADPHH 6 CO2

Glutathion dang oxy hoa Glutathion dang khu oxy Ha sinh i cngPDI by http://www.ebook.edu.vn45

c LactatNADLDH NADHHOxalo acetatPyruvatPyruvate Carboxylase CO2 ATPADPPiCO2 NADP MalatNADPHH Malat decaboxylase MDH NAPNADHH PEP Carboxylase Phosphoenol pyruvat (PEP) CO2GTPGDPI6P I16 DiphosphataseH3PO4H2Od I16 DiPGlucose G 6 Phosphatase H3PO4H2Oe G 6P Hlnh 3.12. Ba giai doan khng thun nghich cuaqua trlnh tng hop glucose tu pyruvat Ha sinh i cngPDI by http://www.ebook.edu.vn46 Hlnh 3.13. Qua trlnh tng hop glucose tu pyruvatHa sinh i cngPDI by http://www.ebook.edu.vn47 4.2.2.Tng hop glucose tu lactat Lactat duoc tao thanh o cac t chuc do su thoai hoa glucose theo con duong duong phn ym khi (nhiu nht o co) se duoc dua vao mau. O do mt phn nho se duoc dao thai ra nuoc tiu, con dai b phn se duoc dua v gan. O gan, lactat duoc su dung nhu mt nguyn liu d tng hop glucose va glycogen. Glucose lai duocchuynramautunhoan,tchuccothunap,chuynthanhlactat(qua trlnh nay se cung cp nang luong cho co hoat dng la mt chu trlnh khep kin la chu trlnh Cori hay chu trlnh lactat. Hlnh 3.14. Chu trlnh acid lactic (Cori) va chu trlnh Glucose alanin

4.2.3.Tng hop glucose tu acid amin Mtsacidamindosuthoaihoaproteintaothanhtrongqua trlnh bin di duoc chuyn thanh mt trong nhung san phm trung gian co kha nang tng hopduocglucose.Cacacidaminnaygoilacacacidaminchoduongduoc chia lam 3 nhom : Nhom I : gm cac acid amin ma qua trlnh chuyn hoa chung se dn dn pyruvat:threonin,glycin,serin,tryptophan,alanin,cysteinvoicac hydroxyprolin. Mu Mu Ha sinh i cngPDI by http://www.ebook.edu.vn48 Nhom II : Cac acid amin chuyn thanh cac san phm trung gian cua chu trlnhKrebsnhu:prolin,arginin,histidin,acidglutamic,glutamin,valin, isoleucin, methiomin, threonin, phenylalanin, tyrosin, acid aspartic va asparagin. Nhom III : Gm cac acid amin chuyn hoa thanh phosphoglycerat, do la : threonin, glycin, serin, hydroxyprolin. 4.2.4.Tng hop glucose tu nhung ose khac. Cac monosaccarid khac glucose nhu galactose, mannose, theo tinh mach cua dn gan, o do duoc chuyn thanh glucose va duoc su dung theo nhu cu co th. ATP ATP Iructohina sc ADPATPADP IIBGal 1 PUDPG PP aldolase ATPHexo ATP Hexokinaxe kinaxegal. uridyl PDA GA ADP trasIerase P Iructo ATPADPUDP gal G P UTP KinaseGK ADP PGA Man.6 P ADP aldolase I16PPman.isomerase epimerase P I.Photphatse Pi I6PUDPG Photpho hexo Issomerase Glycogen SyntetaseG6P G1P GlycogenPglucomutasePhotpholytasePi Pi G6 Photphatase Iruct MannoGalaclGalacto Glucose Hlnh 3.15. Chuyn cac Ose khac thanh glucose o Ha sinh i cngPDI by http://www.ebook.edu.vn49 Bai 4.HOA HOC VA CHUYN HOA LIPID Muc tiu: Nu c nh ngha, phn loi v vai tr ca lipit Nu c c im, tnh cht v vai tr ca glycerid Nu c c im v vai tr ca photpholipit Gii thch c qu trnh chuyn ha axit bo trong c th Tnh c nng lng gii phng khi phn gii hon ton 1 phn t axit bo bo ha. Gii thch c qu trnh chuyn ha TRIGLYCERID trong c th Trnh by c cc qu trnh tng hp triglycerid Phn 1. HOA HOCLIPID I. AI CUONG Lipid thuc nhom hop cht tu nhin khng dng nht, khng hoac it tan trong nuoc va cac dung mi phn cuc, d tan trong cac dung mi huu co nhu ete, benzen, chloroIorm V cu tao hoa hoc, lipid la nhung este cua nhung acid va alcol hoac cua cac dn xut cua acid beo. Lipid co th phn hai loai: Lipid thun gm nhung cht la este cua alcol va acid beo nhu glycerid, cerid, sterid. Lipid tap la nhung cht trong thanh phn cu tao ngoai alcol va acid beo con co nhung nhom khac nhu amin, phosphat, sulIat, glucid, protid. Lipidcophbintrongtbaodngvt,thucvt.Lipidcogiatrinang luong cao chua nhiu loai vitamin tan trong du va nhiu acid beo khng no cn thi t cho co th, lipid tham gia cu tao t bao va con la ngun du tru cho co th. II. THANH PHN CU TAO CUA LIPID 1. Acid beo inh ngha: Acid beo la nhung mono acid phn lon co mach thang, mt scomachvong,thuongcoscarbonchannhungomtslipiddacbitco acid beo co s carbon le.Nhung acid beo trong chui carbon co mt hoac nhiu lin kt di goi la acid khng beo bao hoa. Ha sinh i cngPDI by http://www.ebook.edu.vn50 Acid beo bao hoa: Co cng thuc chung CnH2n1COOH nhung acid beo bao hoa ph bin la:Acid butyric: C3H7COOH ; Acid Palmitic: C15H31COOH ; Acid Stearic: C17H35 COOH . Acid beo khng bao hoa co tu mt hoac nhiu lin kt di nhu: Acid Oleic:C18:1:9; Acid Linoleic: C18:2;9:12;Acid Linolenic: C18:3;9:12:15.Acid Arachidonic: C20:4;5:8:11:14. Acid beo co th tac dung voi kim tao thanh mui cua acid beo, tac dung voi alcol tao thanh este co phan ung cng voi halogen, hydrogen hoa nhung acid beo chua bao hoa. 2. Alcol cua lipid Glycerol, tham gia trong cu tao Glycerid, Phospholipid. Aminoalcol, Cholin, Cerin, Inositol, Sphingosin tham gia cu tao lipid tap Phospholipid. Alcol vong sterol, chu yu la cholesterol, tham gia cu tao sterid. Hlnh 4.1. Cng thuc cu tao cua cholesterol Cac alcol cao phn tu tham gia trong thanh phn cu tao cua xerid (sap), nhu sap ongIII. CU TAO LIPID THUN 1. Glycerid: Glycerid la este cua glycerol va acid beo, co cac dang sau: CH3 HOCH3 CH3 CH3 CH3 CH3 Ha sinh i cngPDI by http://www.ebook.edu.vn51

Hlnh 4.2. Cng thuc cu tao cua glycerid Tinh cht ly hoa cua Glycerid: Glycerid khng tan trong nuoc, it tan trong cn, tan trong cac dung mi huu co. Glycerid chua acid beo hoa thuong o th dac goi la mo. Glycerid chua acid beo khng boa hoa thuong o th long goi la du. Glycerid co th thuy phn boi kim, acid hoac enzym Lipase tao thanh cac san phm Diglycerid, monoglycerid, Glycerol va acid beo. Su thuy phn cht beo bang kim duoc goi la xa phong hoa, mui cua acid beo goi la xa phong. Trn thuc t, tinh cht cua cac cht beo duoc dac trung bang nhung chi s sau dy: -Chi s xa phong hoa: la s mg KOH d xa phong hoa 1g du hay mo. Chi s nay ty l nghich voi trong luong phn tu cua du, mo. -Chi s acid: la s mg KOH cn thit d trung hoa acid beo tu do cua 1 gam mo. Chi s nay giup cho vic tlm hiu luong acid beo tu do cua du, mo. -Chi s Iod: la chi s th hin muc d khng no cua acid beo khng no trong du, mo. Cac cht du co chi s iod cao hon so voi cac cht mo vl du co nhiu acid beo khng no hon mo Ngoai ra cac cht beo d lu ngay thuong bi i, co mui vi khet kho chiu. o la do cac lin kt di cua cac acid beo khng no trong phn tu cht beo co th bi oxy hoa tao nn nhung lin kt peroxyt ri tao thanh nhung aldehyd va nhung acid beo bay hoi, nhung cht nay thuong khng co loi cho suc khoe. Do do khng nn an du mo d lu ngay. 2. Cerid: Cerid con goi la sap, la nhung lipid thun, trong do acid beo este voi alcol cao phn tu, cerid co trong dich tit cua dng vt, cu tao cua sap ong, sap CH2OCOR1CH OCOR2CH2OCOR3CH2OCOR1CH OHCH2OHCH2OCOR1CH OCOR2CH2OHMONOGLYCERIDDIGLYCERID TRIGLYCERIDHa sinh i cngPDI by http://www.ebook.edu.vn52 cua thuc vt, vi khun koch, hansen.Do do cac vi khun nay khng bi tac dung cua cn, acid. 3. Sterid: Sterid la este cua acid beo voi sterol. Sterol quan trong la cholesterol, ngoai ra con co 7 dehydrocholesterol (o da, du ca), ergosterol (men, lua mach), chung la tin cht cua vitamin D. Sterol co trong mo duoi da, trong mau nguoi va dng vt.Trong t chuc va cac dich dng vt cholesterol o duoi dang tu do hoac este hoa voi acid beo goi la cholesterid.Cholesterid duoc thuy phn boi enzym cholesterol esterase V. LIPID TAP 1.Phosphoglycerid ( con goi la glycerophospholipid hay glycerophosphatid hay diacyl phosphatid): La nhung cht lipid trong thanh phn cu tao co glycerid va acid phosphoric. Phosphoglycerid du la dn xut cua acid phosphatidic, bao gm: acid phosphatidic, phosphatidyl glycerol, phosphatidyl cholin, phosphatidyl ethanolamin, phosphatidyl inositol, phosphatidyl serin, plasmalogen. 1.1.Acid phosphatidic la cht trung gian trong qua trlnh tng hop triglycerid va glycerophospholipid nhung co rt it trong cac m. Thanh phn gm co glycerol, hai gc acid beo va mt gc acid phosphoric. 1.2.Phosphatidyl cholin ( Lecithin). Lecithin co cu tao hoa hoc la dn xut cua acid phosphatidic ma X la cholin (CH2 CH2N (CH3)3. Lecithin duoc chit sut tu long do trung. Cht nay co ph bin trong cac t bao cua co th dng vt, dac bit trong gan, nao, long do trung. 1.3.Phosphatidyl ethanolamin ( Cephalin). Cephalin khac lecithin o ch X la ethanolamin (CH2. CH2NH2 )Cephalin co nhiu trong nao va m thnI kinh 1.4.Phosphatidyl serin la dn xut cuaacid phosphatidic ma X la serin (CH2CH NH2 ) 1.5. Phosphatidyl inositol la dn xut cua acid phosphatidic maX la inositol. Phosphatidyl inositol co trong dng vat ( nao), thuc vt ( du tuong, lac, mm lua ml). Ha sinh i cngPDI by http://www.ebook.edu.vn53 1.6.Cardiolipin (diphosphatidylglycerol) Tlm thy trong ty th 1.7. Plasmalogen chim khoang 10 phospholipid cua nao va co. 2 . Sphingolipid: La thanh phn cu tao quan trong cua mang t bao dng vt va thuc vt, dac bit o m nao va thn kinh.Sphingolipid co cu tao hoa hoc gm alcol la Sphingosin . Nhom ruou nay lin kt voi acid beotao thanh ceramid. Cac ceramid co th lin kt voi phospho nhu: Sphingomyelin co nhiu o nao va m thn kinh, co th duoc xp vao loai phospholipid. Cac sphingolipid co th chua cac ose ( don duong)nhu cerebrosid, sulIatid, gangliosid co th duoc xp vao loai glycolipid, gap o nao va nhiu m khac. 3. Glycolipid: La nhung lipid khng co phosphat va ngoai Sphingosin, acid beo con co chua mt hay nhi u Ose nhu Glucose, Galactose.Co nhung loai chinh sau: Cerebrosid: Co nhiu o nao va m thn kinh. Sulphatid: Dn xut cua cerebrozid trong do galactose duoc este hoa o C3 voi H2SO4. Gangliosid: Co o cht xam cua nao, lach, hng cu, co nhiu o vung du dy thn kinh tham gia vao vic dn truyn xung dng thn kinh. 4. Lipoprotein: Cu tao gm lipid va protein, tan duoc trong nuoc, dang vn chuyn va chuyn hoa lipid trong mau. Phn 2 CHUYN HOA LIPID I. AI CUONGLipid trong co th duoc tao thanh mt phn (lipid ngoai sinh) nho su tiu hoa,hp thu vn chuyn tu thuc an,mt phn (lipid ni sinh) tu qua trlnh sinh tng hop trong co th. Lipiddongvaitroquantrongtrongsucungcpvadutrunangluongchoco th(oxyhoa1gtuglyceridcho9,3Kcal,oxyhoa1gprotidhayglucidcho khoang 4,1 Kcal). Lipid la thanh phn quan trong tham gia vao cu tao t bao, t chuc, dac bit la cu tao mang t bao, mang nhn, mang ty th. Lipid va cac san phm chuyn hoa cua chung trong co th tao ra nhiu cht co hoat tinh sinh hocnhuhormonsinhduc,hormonvothuongthn,acidmt,muimt,tin vitamin D... Ha sinh i cngPDI by http://www.ebook.edu.vn54 Su hp thu lipid con kem theo su hp thu cac vitamin tan trong lipid nhu vitamin A, D, E, K va mt s acid beo khng no cn thit cho co th (Vitamin I).Dangvnchuyn,chuynhoalipidotrongmaulacaclipoprotein(VLDL, LDL,HDL),chylomicroncungdongvaitroquantrongtrongchuynhoa,vn chuyn, ri loan chuyn hoa lipid cua co th. III. CHUYN HOA ACID BEOAcid beo co ngun gc ngoai sinh, ni sinh, co vai tro trong su thoai hoa d cungcpnangluongchocothhoatdng,thamgiavaoquatrlnhchuynhoa khac. Acid beo con tham gia cu tao lipid, dac bit acid beo chuidai tham gia cu tao lipid mang va lin kt voi apolipoprtein. 1. Thoai hoa acid beo bao hoa co s carbon chan Thoaihoaacidbe obaohoabangconduongoxyhoaxayrachuyuo gan, ngoai ra con xay ra o nhung co quan khac nhu thn, phi, co, t chuc nao . TheoKnoop(1904)chorangacidbeoduocthoaihoabangcachbicat ngandndimimtmuhaicarbonketuduconhomcarboxyl.Quatrlnh thoai hoa acid beo la qua trlnh oxy hoa acid beo vl suoxy hoa acid beo xay ra o vi tri carbon.

Qua trlnh thoai hoa acid beo gm hai giai doan: Giai doan 1: Hoat hoa acid beo va vn chuyn acylCoA tu bao tuong vao trong ty th.Giai doan 2: Qua trlnh oxy hoa xay ra trong ty thgm co 4 buoc Buoc 1: Phan ung khu hydro ln thu nht Buoc 2: Phan ung kt hop nuoc Buoc 3: Phan ung khu hydro ln thu hai Buoc4:PhanungphncatcetoacylCoAtaothanhacetylCoAvaacylCoA (n2) C. Phn tu acylCoA ngan di hai carbon lai tip tuc bn buoc nhu trn cua su oxyhoa,Nhuvy,vidumtphntuacidpalmiticco16Ckhihoathoathanhpalmityl CoA se qua 7 vong oxy hoa, giai phong 8 phn tuacetyl CoA. S phn acetyl CoA: RCH2 CH2 COOH Ha sinh i cngPDI by http://www.ebook.edu.vn55 AcetylCoAduoctaothanh,seduocdivaochutrlnhKrebsoxyhoahoan toan tao CO2, H2 O va 12 ATP. AcetylCoAcoththamgiavaovictnghopsterid(cholesterol),tng hop acid mt, tng hop acid beo tro lai. Acetyl CoA cung duoc tao thanh cac th cetonic, qua trlnh tao th cetonic xayramanhtrongnhungtruonghopnhindoi,bnhdaithaoduong.Cht cetonic duoc tao thanh trong ty th cua gan dac bit la t bao nao, vao mau ri chuyn toi nhung t chuc ngoai bin d su dung. Nang luong cua qua trlnh oxy hoa acid beo bao hoa:Su hoat hoa acid beo tao thanh acylCoAo ngoai ty th cn cung cp 2 ATP Phan ung khu hydro ln 1, tao IADH2 di vao chui HHTB tao: 2ATP Phanungkhuhydroln2,taoNADHHdivaochuiHHTBtao: 3ATP Mt phn tu AcetylCoA di vao vong Krebs tao: 12 ATP Nhu vy, mt phn tu acid beo co nC oxy hoa hoan toan se tao ra: |(n/21)5 (n/2 . 12) ]2 ATP Giai doan 1 : RCOOH Coenzym A.ATP Thiokinase Mg AMP PP RCOS CoA CarnitintransIeraseCarnitin HSCoA Mang bao tuongRCOS Carnitin Ti th RCOS Carnitin HSCoA CarnitintransIeraseCarnitin RCOS CoA Hlnh 4.3. So d tom tat qua trlnh thoai hoa acid beo giai doan 1. Ha sinh i cngPDI by http://www.ebook.edu.vn56 Giai doan 2 : Qua trlnh oxy hoa: 2. Tng hop acid beo Qua trlnh tng hop acid beo tu acetyl CoA thuong xay ra manh nht o m mo, gan, rut. Hin nay nguoi ta bit duoc it nht ba qua trlnh tng hop acid beobao hoa. Tng hop o bao tuong Tng hop o trong ty th Tng hop o microsom Ci tricacidcycle Acyl CoA Enoyl CoA hydroxyacyl CoA cetoacyl CoA RCH2 CH2 COSCoA IAD p/u khu H2 ln 1 AcylCoADehydrogenaseIADH

RCH CHCOSCoA H2O EnolylCoA Hydratasep/u kt hop H2O OH RCH CH2COSCoA NAD ydroxy AcylCoAp/ukhuH2 ln 2 DehydrogenaseNADH H

RCO CH2COSCoA CoA.SH p/u phn cat Thiolase RCOSCoA CH3COSCoA Acyl CoA Acetyl CoA Taoxetonic:acetone,acetoacetyl,hydroxybutyricTnghop:A.Beo, Cholesterol Hlnh 4 4 So d tom tat qua trlnh thoai hoa acid beo giai doan 2Ha sinh i cngPDI by http://www.ebook.edu.vn57 Qua trlnhtng hop acid beo xay ra o bao tuong la chu yu, duoc xuc tac cuamtmultienzymgmmtthop7proteinganlinvoinhaugoilaacyl synthetase. Acylsynthetaseco1tiudonviproteinnamogiuachuyngcacylco mang nhomSH goi la SH trung tm (ACPAcylCarrierprotein) va 6 tiu don vi enzym mang nhomSH ngoai bin. Nguyn liu tng hop acid beo la cac don vi acetyl CoA ngun gc tu cac cht glucid, cac acid amin hoac tu chinh acid beo. Trong tam don vi acetyl CoA dtaothanhacidbeopalmiticthlchicomt don vi la do acetyl CoA truc tip duoc cung cp, con bay don vi khac la do malonyl CoA cung cp Qua trlnh tng hop AB o bao tuong : Acetyl ACPAcetyl transIcraseAcetyl ACPAcetyl CoA Malonyl transIcraseMalonylACPMalonyl CoA hydroxybutyryl ACPCrotonylACP CH3 COSCoAHSACP CH3 COSACPCoASH HOOC CH2 COSCoAHSACP HOOCCH2 COSACPCoASH TransIerase ANgung tu CH3COSACP COOH CH2 COSACP Malonyl ACP (1)HSACP CO2

B Khu ln mtCH3COCH2COSACP Acetoacetyl ACP NADPH.H (2)NADP CKhu nuoc CH3CHOHCH2COSACP (3)H2O DKhu ln haiCH3CHCHCOACP NADPH.H (4)NADP

CH3CH2CH2COSACP ButyrylACP Ha sinh i cngPDI by http://www.ebook.edu.vn58 1. ceto acylACP syntetase2. ceto acylACP reductase 3. hydroxy acyl ACP dehydratase4. Enoyl ACP reductase ButyrylACPtaothanhlaitiptucphanungvoiphntumalonylACP moi va sau mt vong thu hai nhu trn se tao nn mt acid beo dai hon hai carbon tuc la 6 carbon. Su keo dai chui acid beo cu tip tuc toi acid beo. Giai doan cui cung cua sutnghoplasugiaiphongACPkhoiacylACPsongsongvoisutaothanh acyl CoA. Phuong trlnh tng quat cua qua trlnh tng hop acid palmitic tu acetyl CoA: 8 acetyl CoA 14 NADPHH ATP. acid palmitic 8 HSCoA 14 NADP 7 ADP 7H2O IV. CHUYN HOA TRIGLYCERID1. Thoai hoa Phn lon su thuy phn triglycerid xay ra chu yu o m mo duoi su xuc tac cuaenzymtriglyceridlipasetaothanhsanphmlaacidbeo,glycerol,suthuy phn xay ra nhanh o vi tri A sau do thuyphn chm o vi tri B. San phm co th tip tuc chuyn hoa theo con duong phn, hoac sinh tng hop glucose qua trung gian tao thanh phosphodioxyaceton, phosphoglyceraldehyd hoac glycerol co th thoaihoadiivaochutrlnhKrebssaukhichuynhoathanhacetylCoA.Acid beothoaihoadcungcpnangluonghoacacidbeothamgiavaotnghop lipid. 2.Tng hop Xay ra chu yu o gan, thn, m mo, rut. Ngun nguyn liu la glycerol, acid beo. Glycerol se duoc hoat hoa duo i dang glucerol 3 phosphat va acid beo duoc hoat hoa duoi dang accetyl CoA. V. CHUYN HOA PHOSPHOLIPID 1. Thoai hoa Duoi su xuc tac cua cac enzym phospholipase cac phospholipid duoc thuy phnotchucthanhcacacidbeo,glycerolvamtsalcolkhac(sphingosin, inosin), acid phosphoric, cac cht co chua nito (cholin, ethanolamin, serin...) 2. Tng hop Nhung phospholipid tham gia vao thanh phn cu tao cua cac mang va cac lipoproteinvnchuyn.Tnghopphosphotidylethanolamin(cephalin) Ha sinh i cngPDI by http://www.ebook.edu.vn59 phosphatidyl cholin (lecitin), hai qua trlnh nay d tng hop tuong di ging nhau chi khac la mt bn su dung ethanolamin mt bn su dung cholin. Ngoai ra sphingosinmyelin, glycolipid duoc tng theo nhung con duongring. VI. Chuyn hoa cholesterol Cholesterolthamgiavaothanhphncutaocuamangtbao,quatrlnh tnghopnhiuhormonesteroid.Cholesterolconhiutrongthucannhuthit, gan, nao, long do trung duoc co th hp thu goi la cholesterol ngoai sinh. Phn lon cholesterol duoc tng hop boi nhung t bao, chu yu la gan, cholesterol nay goi la cholesterol ni sinh. 1. Hp thuvn chuynthoai hoa Cholesterolthucanduochpthuorutcungvoicaclipidkhac.Trong phn tuchylomicroncholesterol ngun gc ngoai sinh, n i sinh duoc mau dua toicactbaoduoidangkthopvoilipoprotein,LDLcholesterolvnchuyn cholesterol vao trong t bao , HDLcholesterol vn chuyn cholesterol tu t bao v gan, dao thai qua duong rut hoac tng hop nn acid mt. 2. Tng hop cholesterol Cholesterolduoctnghopchuyuoganrut,ngoairacungduoctnghop o thuong thn, tinh hoan, bung trung, da, h thn kinh. Qua trlnh tng hop cholesteroll co th chia lam 3 giai doan: Giai doan 1 : su tao thanh hydroxymetyl glutaryl CoA (HMG CoA) Giai doan 2 : chuyn HMG CoA thanh squalen. Giai doan 3 : chuyn hoa squalen thanh cholesterol 3. Tng hop cholesterol este Cholesterol este co th duoc tng hop boi hai con duong khac nhau : Su tao thanh cholesterol este duo i su xuc tac cua enzym cholesterol este phosphoethanolamin cytidyltransIerase ethanolamin kinase phosphotidylethanolaminDiacylglycerol CDPethanolamin phosphoethanolamiethanolamin ATPADPCTPPP Ha sinh i cngPDI by http://www.ebook.edu.vn60 synthetasexayrachuyuocactchucgan,rut,thuongthn.Quatrlnhnay cnhaiiphanung:truoctinacidbeoduochoathoaboiHSCoAthanhacyl CoA voi su tham gia cua ATP, sau do acylCoA tac dung voi cholesterol nho xuc tac cua acylCoA cholesterol acyl transIerase tao ra cholesterol este. Conduongthuhaixayraohuyttuongvaduocxuctacboilecithin cholesteroll acyl transIerase (LCAT). Trong phan ung nay acid beo gan o vi tri 2 cua lecithin duoc chuyn truc tip toi cholesterol khng qua trung gian cua acyl CoA. LACTduoctnghopogan,baititvaohuyttuongvahoatdngohuyt tuong.Phan ung este hoa cholesterol nham ly cholesterol chuyn vao HDL dao thai ra mt. Bi 5 HOA HOC VA CHUYN HOA PROTID Muc tiu: LCAT Cholesteroleste Lysolecithin Lecithin Cholesterol HSCoAAcyl CoA cholesterol acyltransIerasecholesterol esteAcyl CoA cholesterolHa sinh i cngPDI by http://www.ebook.edu.vn61 1. Phn loai duoc acid amin. 2. Trlnh bay duoc 4 bc cu truc cua phn tu protein. Nu duoc nhung tinh cht va vai tro sinh hoc quan trong cua peptid, protein.3. Vit c cng thc cu to ca peptit. 4.Vit duoc cac phan ung thoai hoa chung cua acid amin. HOA HOC ACID AMIN, PEPTID, PROTEIN I. AI CUONGon vi cu tao cua protein la cac acid amin, proteinchim ty l hon 50 trongluongkhcuatbao;lathanhphncutaochinhcuaenzym,mts hormon co ban cht la protein, nucleoprotein. co th noi no la co so vt cht cua su hoat dng trong moi co th sng . II. ACID AMIN1. Cu tao:Co 20 acid amin chinh tham gia cu tao protein, chu yu duoi dang acid amin voi cng thuc chung :

Dua vao cu tao cua gc R chung duoc phn loainhu sau: Acid amin trung tinh* Glycin (ky hiu Gly)

* Alanin (ky hiu Ala) * Valin (ky hiu Val)

H CH COOHNH2CH3CH COOHNH2CH3CH CH COOHCH3NH2CH3CH2CH CH COOHCH3NH2R CH COOHNH2Ha sinh i cngPDI by http://www.ebook.edu.vn62 * Leucin (ky hiu Leu) * Isoleucin (ky hiu Ile)

* Serin (ky hiu Ser) * Threonin (ky hiu Thr)

* Cystein (ky hiu Cys)

* Methionin (ky hiu Met)

Acid amin acid va cac amid cua chung* Acid aspartic (ky hiu Asp)

* Asparagin(ky hiu Asn)

* Acid glutamic (ky hiu Glu) CH3CH CH2CH COOHCH3NH2CH2CH COOHNH2OHCH3CH CH COOHNH2OHCH2CH COOHNH2SHCH2CH2CH COOHNH2SCH3HOOC CH2CH COOHNH2CH2CH COOH OC HNNH2CH2CH2HOOC CH COOHNH2Ha sinh i cngPDI by http://www.ebook.edu.vn63

* Glutamin (ky hiu Gln) Acid amin kim * Arginin (ky hiu Arg)

* Lysin (ky hiu Lys)

Acid amin co nhn thom * Phenylalanin(ky hiu Phe)

* Tyrosin(ky hiu Tyr)

Acid amin di vong * Histidin (ky hiuHis)

* Tryptophan (ky hiu Trp )

CH2CH COOHNH2CH2OC H2NH2N C NH CH2CH2CH2CH COOHNH NH2CH2CH2CH2CH COOHNH2CH2NH2CH2CH COOHNH2CH2CH COOHNH2HONH NCH2CH COOHNH2 NHCH2 C HC OOHHa sinh i cngPDI by http://www.ebook.edu.vn64 * Prolin(ky hiuPro) Ngoai ra con gap mt s dn xut khac nhu hydroxylysin, hydroxyprolin, homocystein, citrulin ... 2. Tinh cht ly hoc 2.1. Tinh hoa tan D tan trong nuoc, khng tan hoac tan it trong alcol Khng tan trong ete, tru prolin va hydroxyprolin tan trong alcol va ete Cac acid amin thuong tan trong acid va kim loang tao thanh cac mui cua acid amin. 2.2. Vi a s acid amin co vi ngot kiu duong: Gly, Ala, Val, Ser, His... Ngot kiu dam: mui natri cua acid glutamic. ang: Arg, Ile. Khng vi: Leu. 3. Tinh cht hoa hoc phan ung Ninhydrin. Ninhydrintacdungvoiacidamintrongdiukindunnongtaothanh CO2,NH3,aldehytvaninhydrinbikhu.Saudoninhydrinbikhungungtuvoi ninhydrin khng bi khu tao nn san phm mau xanh tim. Prolin va hydroxyprolin cho mau vang nhat voi Ninhydrin. Cac phan ung do gc R: Gc R quyt dinh cac phan ung dac hiu cua acid amin. Mi phan ung dac trung cho tung acid amin. Sakaguchi: tlm Arginin. Pauly (Diazo): Tyrosin, Histidin. Xanthoproteic: Acid amin nhn thom. COOHNHHa sinh i cngPDI by http://www.ebook.edu.vn65 chl SulIur: Cystein, Cystin. Hopkinscole: Tryptophan. 4. Tinh ch t AcidBase cu a acid amin(luo ng tinh) AcidaminconhomcarboxylCOOHthhintinhacid,dngthoico nhom amin NH2 th hin tinh base, vl vy acid amin co tinh cht luong tinh. O mi truong kim, acid amin phn ly nhu mt acid va thanh anion. O mi truong acid, acid amin hoat dng nhu mt base va thanh cation. Trong dung dich nuoc, acid amin bao gio cung co 3 dang ion: cation, ion luong cuc va anion. duoc ung dung trong ky thut din di acid amin. III. PEPTID 1. Cu tao Peptid la nhung cht duoc cu tao boi cac acid amin ni voi nhau qua lin kt peptid, co phn tu luong 10.000. 1.1.Lin kt peptid La lin kt giua nhom COOH cua acid amin nay voi nhom NH2 cua acid amin kia bang cach loai di mt phn tu H2O. Ban cht hoa hoc cua lin kt nay la lin kt dng hoa tri R CH COOHNH2OH-R CH COO-NH2+ H+Anion R CH COOHNH2R CH COOHNH3+

H+CationR CH COOHNH2R CH COOHNH3+

H+CationH+R CH COO-NH2AnionIon lng ccH2N CH CO OHR1H HN CH CO OHR2H HN CH COOHRnH2OH2N CH CO NH CH CO NH CH COOHR1R2Rn Ha sinh i cngPDI by http://www.ebook.edu.vn66 O mt du chui peptid la acid amin co nhom amin (NH2) tu do, do laacidaminNtn;dukiacuachuipeptidlaacidaminconhomcarboxyl (COOH) tu do, do la acid amin Ctn.1.2.Lin kt hydro (H...O) Laluchuttnhdingiuanguyntuhydrothuadinduongvanguyntu oxy thua din m Lin kt hydro la duy trl cu truc khng gian cua chui polypeptid, dac bit la cu truc bc II. 1.3.Lin kt disulIua (SS) La lin kt dng hoa tri tao thanh do su kt hop giua hai phn tu cysteinCudisulIuadongvaitroquantrongtrongvicduytrlcutrucbcIII cua protein.1.4.Lin kt mui (hay lin kt ion) LaluchuttnhdingiuacacnhomCOO

vacacnhomNH3

COO

. . . NH3 Ngoairaconcotuongtacgiuacac nhom khng phn cuc, tuc cac nhom ky nuoc2.Danh phap NCCNCCNCR H O RHHHO R HR O RO RCCNCCNCCOHHHHLin kt hydroHa sinh i cngPDI by http://www.ebook.edu.vn67 2.1.Goi theo s luong acid amin 2 Aa: Dipeptid 3 Aa: Tripeptid 4 Aa: Tetrapeptid Nhiu Aa: Polypeptid. 2.2.Goi tn theo nhung gc acid amin NguoitadnguyntnacidaminCtn,connhungacidaminkhacdu duoc di dui thanh yl. Vi du: serylglycyltyroxylalanylleucin. 2.3.Goi theo tn ring Nguoi ta con goi peptid theo tn ring: Vi du:Glutathion:Tripeptid glutamylCysteylGlycin Glucagon: polypeptid gm 29 acid amin Insulin: 51 acid amin. Tinh cht 2.4.Tinh cht acidbase Phntupeptidcungco tinh cht luong tinh va co 3 dang ion trong dung dich. 3.2.Tinh cht hoa hoc Peptid cung cho nhung phan ung tuong tu A. Amin. Ngoai ra peptid con cho thm phan ung Biur. 3.2.4. Phan ung Biur: CH2N2HNCH2NOOCu++/OH-NHCCONHNHCu++NHO-NH CCO-NHOBiure phuc cht tim hngNH CH CO N CH CO NH CH CO.......R1R2R3Cu++/OH-NH CH CO N CH COR1R2NCu++CH CO.......R3Ha sinh i cngPDI by http://www.ebook.edu.vn68 3.Mt s peptid co hoat tinh sinh hoc 3.1.Glutathion: Tripeptid glutamylCysteylGlycin

glutathiondongvaitrocuamththngoxyhoakhu.Glutathioncoo cac m va co quan: gan, thn, lach, tim, phi va dac bit la bao v hng cu. 3.2.Peptid hormon Hormon hu yn ocytocin , vasopressin ACTHlahomontinyn,cotacdungkichthichsutnghophormonvo thuong thn . Insulin co tac dung ha duong huyt. Glucagon co tac dung lam tang duong huyt. 4.3. Peptid khang sinh * Mt s khang sinh co ban cht la peptid :Penicillin, tyrocidin ... IV. PROTEIN Protein gm hang tram dn hang nghln acid amin ni voi nhau bang lin kt peptid.Ngoairaconconhunglinkthydro,linktdisulIur,linktmui, lin kt ion tao thanh mt chui hay nhiu chui polypeptid. G SH G SS G-2HG SH+2HDang lhuDang oxyho aHa sinh i cngPDI by http://www.ebook.edu.vn69 Trong luong phn tu 10.000 1. Cu truc khng gian cua phn tu protein Gm 4 bc cu truc : * Cu truc bc I: La cu truc biu thi su sap xp theo mt trt tu xac dinh cua cac acid amin trong chui polypeptid voi nhung dac dim sau: * Cu truc bc II:Cu truc biu thi su xoan cua chui polypeptid, cu truc nay duoc giu vung boilinkthydrovalinktdisulIua.CutrucbcIIthuongco2dang;dang xoan hlnh lo xo, goi la helice va dang xp lop. * Cu truc bc III: Cu truc nay duoc hlnh thanh do su cun lai mt ln nua tu cu truc bc I vabcII.CudisulIuagiuvitriquantrongtrongvicduytrlcutrucbcIII cua chui polypeptid. * Cu truc bc IV:Comtsphntuproteinduoctaothanhboihaihaynhiuchui polypeptid,cacchuipolypeptidkthopvoinhauboilinktmui,linkt hydro hoac luc Van der Waals tao thanh cu truc bc IV. 2. Phn loai: Co nhiu cach : ngun gc: dng vt, thuc vt, vi sinh vt, chuc nang sinh hoc: protein enzym, hormon, bao v, du tru, vn chuyn... hlnh dang phn tu:soi, cu. kha nang hoa tan thanh phn hoa hoc: * Protein thun: thanh phn cu tao chi la cac acid amin . *Proteintap:thanhphncutaongoaiacidaminconcothanhphn khngphailaacidamin,nhuglycoprotein,lipoprotein,nucleoprotein, chromoprotein. 2.1.Protein thun 2.1.1.Albumin: co o long trang trung, huyt thanh cac dich sinh vt, ... 2.1.2.Globulin:conhiutrongmau,cacm,coquanvacacdichsinhvtcua dng vt.Ha sinh i cngPDI by http://www.ebook.edu.vn70 2.1.3.Protamin: co trong thanh phn cua nucleoprotein t bao sinh duc ca, lach, tuyn giap va nhung co quan nhu m khac. 2.1.4.Histon: co trong nhn t bao dng vt kt hop voi acid nucleic (ADN). 2.1.5. Keratin: la protein soi, chu yu co trong thanh phn cua toc, lng, mong, sung...2.1.6.Collagen: la protein soi cua m lin kt: gn, dy chang, t chuc duoi da, xuong, sun... 2.1.7.Prolamin va glutelin: la nhung protein thuc vt, co nhiu trong cac hat ngu cc (lua mach, lua ml, ng...). 2.2. Protein tap: gm 2 phn Protein thun. Nhom ngoai:Tuy theo nhom ngoai, nguoi ta lai chia protein tap ra lam nhiu loai. 2.2.1. Nucleoprotein: Protein thun: thuong la protamin hoac histon. Nhom ngoai: Acid nucleic,2.2.2. Chromoprotein: gm protein thun va nhom ngoai la cht mau. Vi du: Hb cua hng cu, myoglobin cua co,Ilavoprotein: co nhom ngoai chua riboIlavin 2.2.3. GlucoproteinNhom ngoai chua glucid, vi du mucoprotein co nhom ngoai la mucopolysacarid o xuong, sun, m nng do. 2.2.4. LipoproteinNhom ngoai la lipid: phosphatid, triglycerid, sterol, acid beo...,lipoprotein nay tan trong nuoc 2.2.5. PhosphoproteinCo nhom ngoai la acid phosphoric. Vi du: Casein cua sua dng vt 2.2.6. MetaloproteinCo nhom ngoai la nhung kim loai: Ie, Cu, Zn, Co, Ca, Mg, Pb... Vi du: Ierritin cua gan va lach la Metaloprotein co nhom ngoai la sat. 3.Tinh cht Ha sinh i cngPDI by http://www.ebook.edu.vn71 3.1.Tinhluongcuc:cacphntuproteinvuaconhomNH2vuaconhomCOOH vl vytrong mi truong nuoc tn tai o 3 dang ion khac nhau: ion (), ion (), ion luong cuc .3.2. Su bin tinh cua protein Duoitacdungcuanhiuyut:nhitdcao,tiatungoai,siumacid, kim,kimloainang...proteindbimttinhchtbandu,thidudhoatan giam, tinh cht sinh hoc bi mt. o la su bin tinh. Su bin tinh khng lam dut cac lin kt peptid, ma lam dut cac lin kt hydro,linktmui...lamcutrucproteinbidaoln,Nguoitaphnbit2 dang bin tinh: Bin tinh thun nghich: protein bin tinh tro lai dang ban du Bin tinh khng thun nghich: protein khng tro lai dang ban du cua no.3.3. Tinh cht hoa hoc: Co nhung tinh cht cua acid amin va peptid. 3.4. Tinh cht sinh hoc Chucnangsinhhoccuaproteinrtphongphu:proteinenzymvaprotein hormoncohoattinhxuctac,proteinvnchuyncochucnangvnchuyncac cht trong co th, protein cu truc lam nhim vu xy dung t bao va m...CHUYN HOA ACID AMIN I. SU THUY PHN VA HP THU PROTID 1.Suthu y phn protid o ng tiu ho a: Qua trlnh cat dut cac lin kt peptid nho cac enzym duoc tit ra tu ng tiu hoa (proteinase protease hay peptidase). hai loai peptidase: endopeptidase vaexopeptidase . Endopeptidase:pepsin, trypsin va chymotrypsin Exopeptidase:co 3 loai: *Carboxypeptidasecuadichtuythuyphnlinktpeptidcuichui polypeptide v phia C tn, giai phong cac acid amin tu do. *Aminopeptidasecuadichrut,thuyphnlinktpeptidtncungco nhom amin du, giai phong cac acid amin tu do. HN CH CORHN CH COR'......HN CH COOHR'+H2N CH CO...R'+H2O peptidaseHa sinh i cngPDI by http://www.ebook.edu.vn72 * Dipeptidase cua dich rut, thuy phn cac dipeptid giai phong cac acid amin tu do. 2. Su hp thu cac acid amin Cac acid amin loai L duoc hp thu theo co ch hp thu dng, voi su tham gia cua pyridoxal phosphat. Cac a.amin loai D duoc hp thu theo co ch khuch tan thng thuong. Co hin tuong canh tranh hp thu khi an mt nhom nhiua.amin Trong vai truong hop dac bit, cac protein hay chui peptid lon co th duoc hpthuquamangrutmakhngbithuyphn,gynnhintuongdiunghay mn cam di voi mt s thuc an nhu tm, cua, ca... Mang rut tre co th hp thu duoc protein trong luong phn tu tuong di lon. Nho vy ma cac khang th cua metheo sua duoc hp thu gy tinh min dich cho tre. 3. Su thuy phn protein o t bao Trong lysosom co catepsin A, B, C phi hop voi nhau thuy phn hoan toan proteinthanhacidamin.Khilysosombiphavo,chungduocgiaiphongvatac dung ln protein t bao gy ra hin tuong tu tiu t bao. II. THOAI HOA ACID AMIN1. Cac qua trlnh thoai hoa chung: 1.1 Traodiamin:xuctaclaaminotransIerase(transaminase)cocoenzymla pyridoxal phosphat

Vi du:

Khi tn thuong gan GOT va GPT tang cao trong huyt thanh dac bit GPT GOT Aspartat Glutarat Oxaloacetat Glutamat Alanin Glutarat Pyruvat Glutamat GPT R CH COOHNH2+R1CO COOHR CO COOH +R1CH COOHNH2TransaminaseHa sinh i cngPDI by http://www.ebook.edu.vn73 KhitnthuongtimGOTvaGPTtangcaotronghuytthanhdacbit GOT 1.2. Khu amin: Co 4 con duong : Khu amin hydro hoa: tao ra NH3 va acid tuong ung. Khu amin ni phn tu : tao thanh acid khng no va NH3 .

Khu amin thuy phn: tao thanh acid ruou va NH3. Khu amin oxy hoa: tao acid cetonic va NH3 .

Traodiaminvakhuaminoxyhoalunkthopvoinhau,cacacidamin thuongtraodinhomaminvoicetoglutarattaoglutamat,saudoglutamat dehydrogenasekhuaminduoidangNH3.Milinquancuahaiqua trlnh trn duoc m ta boi so d sau:

1.3. Khu carboxyl Acid cetonicGlutamat Glutamat dehydrogenase Transaminase Acid amin cetoglutarat NH3RCHCOOH 1/2 O2 RCOCOOH NH3 NH2 R CH COOHNH2R CH2COOH + NH3H2+ + NH3CH COOHNH2CH2RR CH CH COOH+ NH3CH COOHNH2RR CHCOOHOH+H2O+CH COOHNH2RR CH2NH2CO2DecarboxylaseHa sinh i cngPDI by http://www.ebook.edu.vn74 Lamtquatrlnhphbin,dacbitovisinhvtdchuynthanhamin tuong ung. Nhiu acid amin bi khu CO2 tao thanh nhung cht co dac tinh sinh hoc: HistidinHistamin Histamin co tac dung dan mach, co co tron, tang tinh thm thanh mach va gy di ung. Cholamin la thanh phn cu tao cua photphatid. G.A.B.A co nhiu trong cht xam t bao thn kinh, cn thit cho hoat dng cua neuron. *Cacamintiptucthoaihoaduoitacdungcua:Monoaminooxydase (M.A.O) va Diamino oxydase (D.A.O) tao thanh aldehyt va NH3. Aldehyt tip tuc oxy hoa tao thanh acid carboxylic. Acidcarboxylicsethoaihoatheoconduongthoaihoacuaacidbeodtao thanh CO2 va H2O. 2. Vn chuyn, chuyn hoa NH3 va chu trlnh ur CH2OHCHNH2COOHCO2Serin decarboxylaseCH2OHCH2NH2SerinCholamin amino butyric acid Acid glutamicNH 2 COOH(CH 2 ) 2 CHCOOHGlutamat decarboxylaseCOOH(CH 2 ) 2 CH2NH2CO2R CH2NH21/2 O2(M.A.O)RCHO+NH3R CHO+H2ONAD+NADHH+RCOOH Histidin decarboxylaseN CH 2 CH2NH2 NHN CH 2 CH COOHNH2CO2HNHa sinh i cngPDI by http://www.ebook.edu.vn75 2.1. Su tao thanh glutamin va su vn chuyn NH3 Amoniac duoc tao thanh o cac m chu yu do qua trlnh khu amin oxy hoa ngoai ra con la san phm cua qua trlnh thoai hoa cua base N purin va pyrimidin. Amoniaclachtdcdivoicothvlvytruockhidaothairangoainophai duoc chuyn thanh cht khng dc. Onguoivacothdngvtsngtrncancoxuongsng:NH3chuyn thanh ur tai gan ri duoc dao thai qua nuoc tiu. O chim va loai bo sat: NH3 duoc thai duoi dang acid uric . Nhiu loai dng vt sng duoi nuoc nhu ca: NH3 duoc dao thai truc tip ra ngoai mi truong. Ha sinh i cngPDI by http://www.ebook.edu.vn76 III. TNG HOP ACD AMIN ng vt co xuong sng, chung chi co th tng hop duoc mt s acid amin tucacsanphmchuynhoacuaglucidvalipid,goilaacidaminkhngcn thit.Cac acid amin khng tng hop duoc, phai ly tu thuc an, duoc goi la acid amin cn thit . Acid amin cn thit Acid amin khng cn thitValinGlycinLeucinAlanin IsoleucinSerin Acid amin M Khu amin oxy hoaNH3 Glutamat Glutamin synthetase

Glutamin

MAU Glutamin

GAN

THN GlutaminGlutamin Glutaminase Glutamat NH3 NH3 H

Ur NH4

Nuoc tiu Hlnh 5.6So d su vn chuyn NH3 trong mau Ha sinh i cngPDI by http://www.ebook.edu.vn77 LysinCysteinThreoninGlutamin MethioninAcid glutamic PhenylalaninAcid aspartic TryptophanAsparagin ArgininTyrosin Histidin Prolin ivoinguoilonargininvahistidinla2acidaminkhngcnthit, nhung di voi tre emla 2 acid amin cn thit. 1. Glutamatduoctng hop theo 2 cachsau 2.Alaninva aspartatduo ct ngho ptu pyruvatva oxaloacetatnho pha n u ng trao d i amin vo i glutamat 3.Tyrosin duoc tng hop tu phenylalanin nho phan ung hydroxyl hoa Phenylalanin hydroxylase NADHH

NAD Phenylalanin Tyrosin

O2 H2O Tng hop tyrosin GPT * Pyruvat Glutamat Alanin Cetoglutarat GOT * Oxaloacetat GlutamatAspartat Cetoglutarat NADHH NAD * NH3 CetoglutaratGlutamat H2O Glutamat dehydrogenase

* GlutaminH2OGlutamat NH3 Glutaminase Ha sinh i cngPDI by http://www.ebook.edu.vn78 4. Glycin duoc tng hop tuCO2 va NH3 voi su tham gia cua N5N10 methylen IH4 va NADHH

5. Prolin duoc tng hop tu glutamat

Glutamat Glutamat semialdehyd NAD NADHHH2O COOHCOOH NN HTng hop prolin Glycin synthetase N5N10 methylen IH4 IH4

CO2 NH3 CH2COOH NADHHNAD NH2

Tng hop glycin Ha sinh i cngPDI by http://www.ebook.edu.vn79 6. Cystein duoc tao thanh tu qua trlnh chuyn hoa cua methionin IV. C. HOA CUA MT S A. AMIN THANH CAC SAN PHM C BIT 1. Su tng hop taurin

Tng hop Taurin Tai gan, taurin kt hop voi acid mt tao thanh mui mt taurocholat, cht nay co tac dung nhu tuong hoa lipid, tao diu kin cho lipase ng tiu hoa thuy phn d dang lipid. 2. Su tng hop glutathion ATP ADP Pi Glutamat Cystein Glutamyl cystein SH O2 SO2H CO2SO2H1/2 O2 SO3H2 CH2CH2 CH2CH2 CHNH2 CHNH2CH2NH2CH2NH2 COOHCOOH CysteinAcid cystein sulIonicHypotaurin Taurin CH3 Methionin Sadenosyl Met. Sadenosyl homocystein H2O Adenosin

H2O Serin Cystein CystathioninHomocystein

Homoserin Tng hop Cystein Cystathionin synthetaseHa sinh i cngPDI by http://www.ebook.edu.vn80

3. Su tao thanh creatinin Creatinphosphatladangdutrunangluongoco,khicocnnangluong creatin phosphat duoc dehydrat tao creatinin va giai phong nang luong cho co su dung. 4. Chuyn hoa cua phenylalanin va tyrosinNH2 HNC ( THN ) NHArginin glycin CH2 transamidinaseHNC NH2 CH2 HNCH2COOHCH2 Glucocyamin CHNH2 H2NCH2COOH OrnithinCOOH Guanidoacetat(GAN) methylIerase CH3 ATP HO N C(CO)ADP NH(P) HNCHNCNCH2 NCH2COOH CH3H2O Pi CH3 Creatinin Creatin phosphat Ha sinh i cngPDI by http://www.ebook.edu.vn81 5. Tao melanin Phenylalanin So d chuyn hoa cua phenylalanin va tyrosin Melanin

C H 2 C HCO O H N H 2 NADNADHH O 2 H 2 OTransaminase N H 3 C H 2 C OCO O H Phenyl pyruvat C O 2 C H 2 C O O H Phenylacetat CH2CH COOHNH2OHTyrosin Parahydroxy phenylpyruvat Parahydroxy phenylpyruvat hydroxylase Homogentisat (Alcapton) Homogentisat oxygenase Iumarat

Acetoacetat Glucid Acetyl CoATyrosin hydroxylase D.O.P.AHormon gip tr ngMelanin CatecholaminPhenylalanin hydroxylase Ha sinh i cngPDI by http://www.ebook.edu.vn82 Melaninlasactcuada,thiutyrosinhydroxylasethlthiumelanindntoi bnh bach tang. Ngoairatyrosinconla nguyn liu d tng hop ra catecholamin (adrenalin va noradrenalin), thyroid (hormon tuyn giap). Bi 6 MI LIN QUAN GIUA CAC QUA TRNH CHUYN HOAMuc tiu: 1.Giaithichduocmilinquanchuynhoacacchttrongcothqua cac cht chuyn hoa trung gian, qua tung cap cht.. MI LIN QUAN GIUA CAC QUA TRNH CHUYN HOA1. Lin quan chuyn hoa giua glucid va lipidNuanmtluonglonglucid,luongduthuasechuynthanhlipidbang cach: Theoconduongphn(glycolyse)taothanhpyruvatrithanhacetyl CoA. Theo con duong pentose phosphat cho NADPHH. AcetylCoAvaNADPHH tnghopthanhacidbeo.Tuphosphoglyceraldehydchuynthanhglycerolphosphatlatinchtdtnghop tryglyceridvaphospholipid.NgoairaacetylCoAlanguynliutnghop cholesterol va nhiu lipid khac. Tryglycerid duoc du tru chu yu o m mo. Trong co th qua trlnh chuyn hoa tu glucid thanh lipid xay ra rt d dang. Lipid thanh Glucid: Lipid theo con duong oxyhoa tao thanh acetyl CoA phnlondivaochutrlnhKrebsdtchaychonangluong,trongtruonghop munchuynthanhglucid,acetylCoAcungphaiquachutrlnhKrebstao oxaloacetat ri tng hop thanh glucose.ylamtconduongdai,traiquanhiugiaidoan.Honnuachutrlnh Krebs chi hoat dng trong mtth cn bang do yu cu nang luong cua co th vl vy su chuyn lipid thanh glucid rt han ch. Trongcothchuynhoaglucidvalipidlinquanchatchevoinhau.Ri loan chuyn hoa glucid dn toi ri loan chuyn hoa lipid. Bnhdaithaoduong(diabetesmellitus)lamttruonghopdinhlnhtrong mi lin quan nay. Trong bnh dai thao duong, qua trlnh duong phn giam do do giampyruvatdntoithiuoxaloacetatlachtkhoid ucuachutrlnhKrebs). Chu trlnh pentose phosphat hoat dng kem dua dn thiu NADPHH.Ha sinh i cngPDI by http://www.ebook.edu.vn83 Ngun acetyl CoA tu glucid bi thiu hut, co th thiu nang luong nn tang phn huy acid beo thanh aceyl CoA. Do thiu oxaloacetat, luong acetyl CoA vao chutrlnhKrebshanch,sutnghopacidbeoxayrakhokhandothiu NADPHH, su tng hop cholesterol cung chi xay ra o mt chung muc nht dinh. Vl vy phn lon acetyl CoA chuyn hoa theo con duong tao cetonic. 2. Lin quan chuyn hoa giua glucid va protid Glucid thanhProtid: Mt s acid cetonic tao thanh trong chuyn hoa glucid, nu tham gia qua trlnh trao di amin thl chung tao thanh acid amin; nhu pyruvat thanh alanin,cetoglutaratthanh glutamat, oxaloacetat thanh aspartat. ProtidthanhGlucid:Mtsacidamin(a.a.)theoconduongchuynhoa ring d tao thanh oxaloacetat, tu oxaloacetat co th tng hop thanh glucose. 3. Lin quan chuyn hoa giua protid va lipid -protid thanh lipid: Mt s acid amin chuyn thanh acetyl CoA, acetyl CoA la nguyn liu tng hop acid beo hoac no theo con duong tn sinh duong tao thanhglyceraldehyd 3phosphat ri tng hop glycerol. -lipid thanh protid Acid beo theo con duong oxy hoa thanh acetyl CoA ri vao chu trlnh Krebs hay chu trlnh acid glyoxylic san phm trung gian la cac acid cetinic lai co th chuyn thanh acid amin.