Trao i trc tuyn ti:www.mientayvn.com/chat_box_hoa.html

CHNG I: PROTEIN

NI DUNG I. I CNG V PROTEIN 1.1. nh ngha 1.2. Chc nng sinh hc

II. THNH PHN CU TO 2.1. Thnh phn nguyn t 2.2. Amino acid 2.2.1. Khi nim 2.2.2. Phn loi 2.2.3. Mt s tnh cht ca amino acid

2.3. Cc bc cu trc ca protein 2.3.1. Cu trc bc I 2.3.2. Cu trc bc II 2.3.3. Cu trc bc III 2.3.4. Cu trc bc IV

2.4. Peptide v thuyt polypeptide 2.5. Tnh cht ca protein 2.6. Phn loi protein 2.4.1 Protein n gin 2.4.2. Protein phc tp

I.

I CNG V PROTEIN V mt ho hc: protein l nhng polyme sinh hc cao phn t c cu to bi monomer l cc amino acid lin kt vi nhau bng lin kt peptide. V mt sinh hoc: protein l cht hu c mang s sng

1.1. Khi nim:

1.2. Chc nng sinh hc ca protein Xc tc Vn chuyn: Hemoglobin: v/c O2, CO2, proton Albumin: v/c bilirubin, acid bo Lipoprotein: v/c lipid gan cc c quan

Dinh dng v d tr: Ferritin: Fe2+ Ovalbumin, casein

Vn ng: Actin, myosin Tubilin

Cu trc Collagen: gn, sn Elastin: dy chng Keratin: lng, mng, tc

Bo v:

Immuloglobin (Ig) Fibrinogen, thrombin iu ho:

ng mu

iu ho qu trnh chuyn ho cc cht: protein, carbohydrate, lipid... Vd: Protein G hormone

Cung cp v d tr nng lng: p ng 10-15% nhu cu nng lng cho c th Khi oxy ho 1g protein 4.1 kcal

II. THNH PHN CU TO 2.1. Thnh phn nguyn t C50%, H7%, O23%, N16% nh lng protein theo phng php Kjeldahl. (Phng php Kjeldahl: % CP = %N x 6,25) S 0-3%, P, Fe, Zn, Cu,...

2.2. Amino acid- n v cu to c bn ca protein 2.2.1. Khi nim Amino acid l dn xut ca acid hu c mch thng trong mt hay hai nguyn t hydro v tr carbon c thay th bi nhm amine. R - C H - COOH | Cng thc tng qut NH2 - acid amin

2.2.2. Phn loi 2.2.2.1. Theo quan im ho hc Theo phn cc ca gc RKhng phn cc Alanine Glycine Isoleucine Leucine Methionine Phenylalanine Proline Trytophane Valine Phn cc Acid aspartic Acid glutamic Arginine Asparagine Cystein Glutamine Histidine Lysine Serine Threonine Tyrosine

AA phn cc AA khng phn cc

Theo cu to ho hc ca gc R

2.2.2.2. Theo quan im dinh dng Amino acid khng thay th (indispensable amino acid) hay aa thit yu (essential amino acid) Amino acid thay th (dispensable amino acid) hay aa khng thit yu (inessential amino acid) Amino acid bn thay th (semi-dispensable) hay bn thit yu (semi-essential)

Mt aa c gi l khng thay th hay thay th ph thuc vo: Loi v giai on ca c th VD: 10 EAA ln l Phe, His, Ile, Leu, Lys, Val, Met, Arg, Thr v Trp. Ngi trng thnh: 8 EAA (ngoi tr His v Arg trong 10 loi trn). tr con, cng ging nh ln, c 10 aa trn u thit yu.

S c mt hay khng ca acid amin khc Met Cys, nn khi thiu Met Cys l EAA. Phe Tyr, nn khi thiu Phe Tyr cng l EAA Ch : TV v mt s VSV t/hp c tt c cc aa

nhu cu ca tng ging, loi v giai on pht trin ca c th 2.2.3. Mt s tnh cht ca amino acid 2.2.3.1. Tnh hot ng quang hc

ngha: cung cp y cc aa thit yu theo

Cc aa (tr glycine) u c carbon bt i xng c tnh hot ng quang hc quay mt phng phn cc ca nh sng tri, phi.

Nu nhm NH2 gn bn phi C* D (dextrorotatory) Nu nhm NH2 gn bn tri C* L (levorotatory) S ng phn=2n (n- s C*) Trong t nhin: D-aa vi khun, peptide khng sinh L-aa protein ng vt, thc vt

+

COO + l H3N C* H l CH3 L- Alanin

COO l + H C* NH3 l CH3 D - Alanin

2.2.3.2. Tnh lng tnh v im ng in Amino acid c: Nhm carboxyl (-COOH) nhng proton (H+) Nhm amin (-NH2) nhn proton (H+) base

acid

Vd: Alanine Nh mt acid (cho H+) COOH + l H3N C H H+ l R Nh mt base (nhn H+)COO + l H3N C H l R COO + l H3N C H l R COOH l H2N C H l R

+

+ H+

Trong mi trng acid aa (+), nu pH aa nhng proton 1 aa (trung ho v in), nu pH aa nhng proton 2 aa (-): COOH H+ COO COO + + l l H + l H3N C H H3N C H H2N C H l l l R + R + H H R pH = 2,31 pH = 5,97 pH = 9,6 Tuy thuc vo pH m/t aa tn ti dng no. pH m/t m ti aa dng ion lng cc (trung ho v in, khng mang in) pH ng in (im ng in) pI(point isoelectrical) Khi dng in 1 chiu chy qua dd cha aa (pH m/tpI) th:

pH m/t=pI pH m/tpI

aa lng cc, khng di chuyn aa (+), di chuyn v cc (-) aa (-), di chuyn v cc (+)

ng cong chun c trng ca dd Glycine 0,1mol 25C c 3 im un:

2.2.2.3. Phn ng c trng ca aa Phn ng vi axit HNO3

Phn ng vi aldehyde formic

Phn ng vi ninhidrin

Phn ng nito ho v halogen ho

Phn ng ca gc R Phn ng oxy ho kh

Phn ng amid ho

Phn ng phosphoryl hoSerine + axit phosphoric Phosphoserine

2.3. Cc bc cu trc ca protein

2.3.1. Cu trc bc I 2.3.1.1. nh ngha L cu trc ca 1 chui polypeptide nm trong mt phng, cc aa lin kt vi nhau bng lin kt peptide theo mt trnh t nht nh c trng cho tng loi protein. S chui polypeptide tng qut

2.3.1.2. S hnh thnh lin kt peptide Do s loi nc gia nhm carboxyl v tr C ca aa ng trc vi nhm -NH2 ca aa ng sau:

Hai aa lin kt vi nhau 1 l/k peptide dipeptide Ba aa lin kt vi nhau 2 l/k peptide tripeptide Mt s aa lin kt vi nhau oligopeptide

Trong chui polypeptide c hai aa hai u: u cha NH+3 t do gi l u N v mang s 1, cc aa tip theo l s 2, 3, 4, . AA cui cha nhm COO- t do l aa u C.

2.3.1.3. ngha cu trc bc I ca protein L cu trc c bn, quan trng nht protein tnh cht ca protein: Vn ni ging Phm cht Kh nng chng chu bnh tt c qui nh bi s lng v trnh t cc aa trong chui polypeptide. S lng aa trong lng phn t ca protein. Trnh t sp xp ca cc aa th gii SV c s lng v cc kiu protein khng l m ch t 20 loi - aa. Vd:

Trnh t sp xp ca cc aa trong protein l do m di truyn qui nh hin tng di truyn SV chnh l s truyn li cho i sau cu trc bc I ca protein. S thay i v trnh t sp xp ny c th dn n nhng trng hp bnh l.Vd: bnh thiu mu c tnh do hng cu c hnh li lim. Hb cu to t 2 chui v 2 chui . ngi bnh, aa th 6 trn chui l acid Glu Val

2.3.2. Cu trc bc II 2.3.2.1. nh ngha L s tng tc khng gian ca cc gc aa gn nhau hay cnh nhau trong tng on ca chui polypeptide.

2.3.2.1. c im ca cu trc bc II

Xon (-helix) Chui polypeptide cun li theo hnh l xo, to thnh nhng bc xon. Xon /trng cho nhng protein dng cu (protein ca cc m mm nh c, mu; trng, sa. - S tn ti cc bc xon l nh cc lin kt hydro, hnh thnh gia nhm CO- ca aa ny vi nhm NH- ca aa ng trc n 4 gc aa.

Gp np beta: Thng gp nhng protein dng si (nh protein ca t tm, hoc nhng on ngn ca polypetide cc protein trong xng sng). Gp np khc xon ch c cu trc hnh dng tm ch khng phi dng ng, chui polypeptie hu nh dun thng m khng b cun li nh xon . Gp np c n nh nh lkt hydro gia nhm NH- v CO- trong cc chui polypeptid khc nhau (hoc gia nhng on khc nhau trong mt chui). Trong cu hnh gp np , cc chui polypeptide c th nm song song hoc i song song

Song song

i nhau

2.3.3. Cu trc bc III 2.3.3.1. nh ngha Cu trc khng gian 3 chiu ca chui polypeptide, l s tng tc khng gian ca tng on trong chui polypeptide c cu trc bc II hon chnh, to cho phn t c hnh dng n nh v c trng.

2.3.3.2. c im ca cu trc bc III L s sp xp va xon va gp khc mt cch dy c ca chui polypeptide. S tng tc xa ca cc gc aa trong khng gian. c th cho tng loi protein v thch hp cho vic thc hin cc chc nng ca protein. Mi bin i cu trc bc III u ko theo nhng h qu v hot tnh ca protein Vd: Khi pH mt th/i ctb3 th/i TTH ca enzyme b b/i, enzyme mt t/dng vi c cht.

2.3.3.3. Lc lin kt n nh cu trc bc III 2.3.3.1.Disulfid (cng ho tr)

Lk disulfid (-S-S-): lin kt xut hin gia hai gc Cys-2H - Cys- SH + HS-Cys- -Cys-S-S-CysLin kt disulfid

Lin kt ng ho tr, nng lng mch ln, khong 10 kcal/mol. S lng trong protein khng nhiu. i vi protein cha 100- 150 aa ch c 3-5 lin kt ny S ng gp ca lin kt ny vo vic n nh cu trc bc III khng ln. Trong bo tng, pH l tr/tnh, mt c tnh kh, nn lk disulfide kh hnh thnh (tr v dng SH). Do hay gp lk S-S- nhng protein c tit ra ngoi TB ( h/tng, dch gi/bo, ). Cu SS- h/thnh thun li khi pH4)

Glycogen synthase

UDPenzyme r nhnh

chui glycogen di thm 1 phn t glucose lp li 6 ln (n+1)

12

III. S LC QU TRNH PHN GII CARBOHYDRATE 3.1. Phn gii carbohydrate ng vt d dy n-glucosidase Maltose Maltase Glucose

Tinh bt

-amylase Oligo-1,6-glucosidase

Saccharose

-glucosidase saccharase

Fructose

+

Glucose

Lactose

-glucosidase lactase

Galactose

+

Glucose

3.2. Phn gii tinh btOligo-1,6-glucosidase (ct -1,6glucoside)

-amylase (ct - 1,4 glucoside)

maltose

oligosaccharose

-dextrin

13

maltose maltase -dextrin -dextrinase (Oligo-1,6-glucosidase) oligosaccharose Oligosaccharase Disaccharase (glucoamylase) glucoamylase maltase

3.2. Phn gii glycogen c: khi t bo hot ng mnh glycogen glucose ATP. gan: glycogen glucose cung cp cho hot ng ca mi t bo v iu ho hm lng ng huyt c bit thi im xa ba n.

14

Sn phm ca hai giai on phn gii glycogen l: Glucose-1-phosphat (93%) Gluose t do (7%)

IV.S CHUYN HO TRUNG GIAN CA GLUCOSE

4.1. Qu trnh ng phn Cc giai on ca qu trnh ny u din ra bo tng. C th hot ng trong t bo c hay khng c oxy

GlycolysisGlucose + 2ATP + 2NAD+ 4ADP + 2 Pi 2 pyruvate + 2ADP + 2NADH + 2H+ + 4ATP +2H2ONAD+ phi c ti tng hp th qu trnh ng phn mi c tip tc

15

Cc phn ng ca qu trnh ng phn

16

4.2. Cc ng hng chuyn ho tip theo ca pyruvate

NAD+ NADH

Glucose

NAD+ is needed for glycolysis to proceed. Thus, NADH produced in glycolysis must be re-oxidised for glycolysis to continueATP

PyruvateAcetaldehyde

Oxaloacetate AlanineNADH

Ethanol(Yeasts)

Lactate

Acetate Butyrate

Acetyl CoA TCA

Anaerobic conditions

(Working muscle) (Gut and soil bacteria)

3.2. Cc ng hng chuyn ho tip theo ca pyruvate 3.2.1. Chuyn ho pyruvate trong iu kin ym kh

3.2.1.1. Ln men lactic

17

VNG COREY

3.2.1.2. Ln men ru

3.2.2. Chuyn ho pyruvate trong iu kin hiu khPyruvate s c chuyn vo trong ty th,

b kh carboxyl oxy ho hon to thnh acetyl CoA v c t chy hon ton trong chu trnh Krebs. http://www.johnkyrk.com/krebs.html

18

1: Citrate synthase 2: Aconitase 3: isocitrate dehydrogenase 4: -ketoglutarate dehydrogenase 1 8

2

7

3

6 5

4

5: Succinyl-CoA synthetase 6: Succinate dehydrogenase 7: Fumatase 8: Malate dehydrogenase

NADH FADH2 Shuttle

3ATP 2ATP

2 Acetyl CoA

38

19

S LC QU TRNH CHUYN HO GLUCOSE THEO NG HNG PENTOSEPHOSPHATE

Phng trnh tng qutGlucose+ 12NADP+ + 7H2O + ATP 6CO2 +12NADPH+ + H+ + ADP + Pi Pha oxy haGlucose-6-P +NADP+ + H2OGlucose-6-phosphate dehydrogenase

ribulose-5-P + CO2 + 2NADPH

Pha khng oxy ha(sugar interconversions) (transketolase, 2C-units)

ribose xylulose arabinose heptulose

dihydroxyacetone-P fructose-6-P glucose-6-P

20

ngha Cc t bo c s phn chia mnh nh: tu xng, da, t bo nim mc rut non s dng pentose DNA, RNA, ATP, cc coenzymes: NADH, FADH2 v CoA. NADPH cn thit cho nhiu qu trnh sinh tng hp hoc ngn cn s tn thng t bo do cc gc oxygen gy ra. VD: t bo hng cu v mt tng cng kh NADPH thnh NADP+ v to glutathione dng oxy ho ngn cn s tn thng ca cc phn t protein, lipid...

Gan, m m, tuyn v (tng hp acid bo mnh) hoc gan, tuyn thng thn, tuyn sinh dc (tng hp cholesterol, hormone steroid) cn NADPH.

21

Trao i trc tuyn ti:www.mientayvn.com/chat_box_hoa.html

9/27/2010

CHNG VII: LIPID

NI DUNG I. I CNG V LIPID 1.1. Khi nim 1.2. Vai tr 1.3. Phn loi 1.3.1. Lipid n gin 1.3.2. Lipid phc tp

II. S LC QU TRNH TNG HP LIPID

III. S LC QU TRNH PHN GII LIPID

1

9/27/2010

I. I CNG V LIPID 1.1. Khi nim 1.2. Vai tr Cu to mng t bo D tr nng lng Dung mi ho tan vitamin (A, D, E, K) Gi nhit cho c th Bo v c hc Cung cp nc ni sinh Mt s vai tr quan trng khc: Cc hormon steroid Phosphatidylnositol Sphingolipid Eicosanoid Sterol

1.3. Phn loi 1.3.1. Lipid n gin* Triacylglycerol (triglycerid) 3 acid bo + glycerollin kt ester triglycerid.

2

9/27/2010

Tnh cht Khng phn cc, k nc, khng tan trong nc Du thc vt cha nhiu triacylglycerol c acid bo khng no tn ti th lng (t0 phng). M ng vt cha nhiu triacylgycerol c acid bo no (vd: stearin l thnh phn chnh ca m b) tn ti th c (t0 phng). Thc n giu lipid + oxy khng kh lu ngy i. (acid bo khng no oxy ha aldehyde + carboxylic acid c mch C ngn hn ).

* Sp (serid) L ester ca acid bo cao phn t no hoc khng no (C14-C36) v alcol cao phn t (C16-C36)

3

9/27/2010

Tnh cht im nng chy cao hn ca triacylglycerol (60-1000). v c xng sng tit ra cht sp bo v tc, da, gi cho da mm, trn v khng thm nc. Vd: chim, gia cm, thy cm c tuyn phao cu sp chng thm nc.

* Sterol v cc hp cht steroid Acid mt, mui mt, vitamin D, hormon steroid, cholesterol

4

9/27/2010

* Tnh cht Steroid v dn xut ca chng khng thy phn c v cha nhn steran (steroid). Sterol l lipid cu trc, tham gia cu to mng. L tin cht tng hp cc cht c vai tr sinh hc iu khin s biu hin gene. Vd: hormone steroid, ...

5

9/27/2010

1.3.2. Lipid phc tp* Glycocerophopholipid (phosphoglyceride)Acid bo no

Acid khng bo no

Nhm th

(cephalin) (lecithin)

6

9/27/2010

Tnh cht v cha nhiu ether lipid (1 trong 2 chui acyl c gn vi glycerol bng lin kt ether khng phi l ester). Chc nng: Khng li s xc tc ca phospholipase nhm ct t lin kt ester ca acid bo trong lipid mng. Yu t hot ha tiu cu.

*Sphingolipid

- Trong cu trc khng c glycerol m thay bng sphingosine.

7

9/27/2010

Tnh cht L nhm lipid mng ln. Sphingolipid chia thnh 4 nhm nh khc nhau: Sphingomyelin Glycolipid trung tnh (khng tch in) Lactosylceramide Ganglioside

Sphingomyelin c trong mng nguyn sinh ca tb v, c bit mng myelin (tb thn kinh) c td cch in cho phn axon ca tb ny.

8

9/27/2010

Galactolipid v sulfolipid C nhiu thc vt Glactolipid = galactose + 1,2diacylglycerol. Sulfolipid = glucose (c sulphonate ha) + diacylglycerol

II. S LC QU TRNH TNG HP LIPIDTNG HP LIPID (Nguyn liu: glyceraldehyde-3-phosphate, phosphodioxyacetone, acetyl CoA, ATP, NADPH; enzyme: acetyl carboxylase, acyl synthase (6enzyme + ACP)

Tng hp Glycerolphosphate

Tng hp acid bo bo ha

Tng hp acid bo khng bo ha Tng hp acid bo c mch C di Trong microsome

Tng hp triglycerid

Tng hp acid bo bo ha ( bo tng)

Trong ty th

9

9/27/2010

Tng hp acid bo bo ha ( bo tng)

Nguyn liu Acetyl CoA ATP NADPH Enzyme: Acetyl carboxylase Acyl synthase (6enzyme + ACP)

PTTQ ca qu trnh tng hp palmitic acid8Acetyl-CoA + 7ATP + 14NADPH + 14H+ Palmitate + 8CoA + 6H2O + 7ADP + 7Pi + 14NADP+

10

9/27/2010

III. S LC QU TRNH PHN GII LIPIDS OXY HA LIPID

Oxy ha acid bo - oxy ho acid bo no c s C chn acetyl CoA, FADH2, NADH + H+ Krebs th ceton

Phn gii glycerol oxy ho acid bo khng no oxy ho acid bo c s C l

Aceton

Aceto acetate

Chuyn ho th ceton cc m bo

-hydroxybutyrate

Beta Oxidation Round CH3CH2CH2CH2CH2CH2CH2C~S-CoA Cofactor or Substrate O H Dehydrogenase -C=C-C~S-CoA FAD H O TRANS HO Hydratase -C- CH2-C~S-CoA H 2O H LO Dehydrogenase Acyl Transferase -C- CH2-C~S-CoA O O R -C...CH3-C~S-CoA O O S-CoANAD+

HS-CoA

11

9/27/2010

Hiu qu nng lng ca s -oxy ho acid bo 1AB c s carbon chn 2n nAcetyl CoA (n-1) FADH2 5(n-1) ATP (n-1) NADH+H [5(n-1)+12n] - 1 12n ATP

17n 6 (-1ATP

hot ho AB)

ENERGY CONSERVATION Stearic Acid (C18 satd)9 Acetyl CoA 8 FADH2 8 NADH = 108 ATP = 16 ATP = 24 ATP = 148 ATP - 1 ATP 147 ATP

12

Trao i trc tuyn ti:www.mientayvn.com/chat_box_hoa.html

9/27/2010

CHNG VIII: TRAO I CHT V NNG LNG

NI DUNG I. TRAO I CHT 1.1. Khi nim TC 1.2. Chc nng sh c bn ca TC 1.3. ng ho v d ho 1.4.Ba giai on ca s chuyn ho trung gian 2.1. Nng lng t do 2.2. Adenosine triphosphate (ATP) 2.3. Qu trnh vn chuyn in t 2.3.1. Thnh phn ca chui vn chuyn in t 2.3.2. S vn chuyn in t trong chui h hp 2.3.3. Q/trnh phosphoryl ho OXH - tng hp ATP

II. NNG LNG SINH HC

1

9/27/2010

I. TRAO I CHT 1.1. Khi nim Tng p.. h.hc do enzyme x.t, phn ln xy ra trong TB; l h. c m/ch, c tnh /hng v iu tit ph.hp cao.

1.2. Chc nng sh c bn ca TC Khai thc NL t cc h/cht h/c hay t NL /sng m/tri ( cc s/vt q/hp) Bin i cc cht ddng nhn t mts thnh nhng .v c.trc hoc nhng tin cht ca cc th.phn trong TB. Lp rp cc .v c.trc thnh protein, AN, lipid, polysaccharid v nhng th.phn .trng khc ca TB. Kin to v ph.gii cc ph.t s.hc cn thit cho nhng ch.nng ch/ho ca TB.

1.3. ng ho v d ho

Hai q/t c/bn ca TC i lp, th.nht, Lin quan mt thit H tr b/sung cho nhau

D ho:

Phn gii cc h/cht h/c (saccharid, protein, lipidt T hay kho d tr ni bo) cc SP /gin hn cht thi: CO2, H2O, NH3, Pi, vv Nng lng trong cc h/cht h/c b ph/gii c gi/phng, phn ln c t/lu trong ATP s/dng cho nhng h/ sng. ng ho:

Tng hp ca TC. Cc ph/t tin cht nh c dng t/hp nn cc i ph/t: protein, saccharid, lipid, /trng ca TB. i hi NL (t ph/gii ATP).

2

9/27/2010

Hai pha ca TC (ng ho v d ho) l mt mi mu thun thng nht ng ho mi th/phn ca c th, trong c enzim, nh enzim cc p.. ph/gii (d ho) mi xy ra c Cc sn phm trung gian v nng lng to ra trong qt d ho l ng/liu v NL t/hp cc cht x/d TB.Nng lng t cc hp cht hu c (carbohydrate, protein, lipid) Phn t ln ca t bo: protein,acid nucleic, lipid, polysaccharide

ADP+Pi NAD+ NADP+

d ho ATP NADH NADPH

/ho

ATP, CO2, H2O, NH3

Amino aicd, ng, axit bo.

T bo SV T dng (autotrophes)- Dng CO2 tng hp mi hp cht h/c cn thit - Cc SV q/hp, h/hp

D dng (heterotrophes)- Khng c kn dng CO2, ly C t cht h/c c sn do SV t dng to ra. -TB /vt bc cao, phn ln VSV

SV d dng k kh Mt sng vng O2 Khng dng O2, Ln men hiu kh Mt sng c O2 Dng O2, Oxy ha

1.4.Ba giai on ca s chuyn ho trung gian

3

9/27/2010

Giai on I

Acid aminGiai on II

ng nng phn

Glycerol, acid bo

NH3

ATPFADH2 NADH

Pyruvate NADH CO2 Acetyl-CoAGiai on III

ATP Oxaloacetate Malate Fumarate Succinate VNG KREBSChui h hp

Citrate

FADH2 NADH

Isocitrate CO2 -ketoglutarate Succinyl-CoA CO2

CoQ Cc cytochrom O2

ATP

v, giai on I ca d ho bt u bng vic th/phn cc cht dd nh protein, carbohydrate, lipid nh cc enzim ng tiu ho. cc /v c/to t/ng: aa, ng n; cc acid bo, glycerol giai on 2, ng n v glycerol b ph/gii thnh pyruvate (3C), sau thnh acetyl-CoA (2C). Cc aa, acid bo acetyl-CoA Acetyl.CoA l im hi t, l sp chung trong ch/ho ca c protein, carbohydrate v lipid cui giai on 2 Trong giai on 3, acetyl-CoA vo vng Krebs, c OXH trit thnh CO2 v nc. Cc cp hydro cao nng c tch ra (NAD.H v FAD.H2 ) chui h hp. Cc p.. STH cng din ra qua mt s g/, i ngc li vi cc chui p.. d ho.

4

9/27/2010

II. NNG LNG SINH HC 2.1. Nng lng t do L kh/nng sinh cng TB sng cn NL to ra glucose t thn kh v hi nc, nhn i DNA hoc v (co dui c) Tr/thi c/trc c trt t, c m/ t/chc cao ca mt h/thng sng i hi NL vo vic d/tr tr/thi y v cho n h, (V mi vt sng u l h/thng v/l, h/hc chu s ch/phi ca cc ng/l nh//hc. SV chu s ch/phi ca 2 ng/l nhit ng hc:

Ng/l 1: Trong cc qt (v/l v h/hc), NL khng sinh ra v cng khng mt i, m ch ch/ho t dng ny sang dng khc (NL ca mt h/thng v v tr bao quanh lun gi nguyn, khng i). Ng/l 2: Bt k mt qt no cng bin ng theo hng sao cho entropy ca h/thng v v tr bao quanh lun tng dn cui cng t cc i, qt t tr/thi cn bng v ngng din bin v t s ng u v t, C, p, vv. Mt p h/hc hay mt qt v/l trong lc d/bin i ti tr/thi c/bng c kh/n sinh cng hu ch (gi l NL t do, k/hiu G). Qua kh/st b/i entropy, c th bit s NL hu ch theo ph/trnh: G = E - T. S

5

9/27/2010

Trong 1 phh, vi k chun v t, p v C, G c tnh qua Keq. VD, p: aA + bB cC + dD (a, b, c, d: s ph/t ca mi cht tng ng) Hng s c/bng: Keq =C .D A .Ba c d b

Mi l/q gia Keq ca 1 p hh v Go th hin qua pt: Go = - 2,303 RT log10 Keq R= h/s kh (= 1987 cal/mol/); T = t tuyt i

Go = - 2,303 RT log10 Keq Go= Hiu s gia hm lng NL t do ca cc sp c hnh thnh v NL t do ca cc c cht. - Keq = 1 Go = 0, p tr/thi c/bng, khng thu, khng nh NL - Keq 1 Go 0 : p nh NL (exergonic), sinh cng

- Keq 1

Go 0 : p thu NL (endergonic), khng t pht

6

9/27/2010

2.2. Adenosine triphosphate (ATP)- H/ sng SV (v/ng, h/thu dd, STH cc cht, ph/chia TB, u dng ATP l ngun NL. - ATP c ph/hin nm 1929 bp tht. TB v, [ATP, ADP v AMP] lun n nh mc 5-15 mM. - Vng bin chuyn ph/gii v ti t/hp ATP trong TB: ATP + H2O ADP + Pi + W

Nng lg t do thu phn ATP trong k chun: ATP + H2O ATP + H2O ATP + 2H2O ADP + Pi ( Go = - 7,3 kcal/mol) AMP + PPi AMP + 2Pi ( Go = - 7,3 kcal/mol) ( Go = - 14,6 kcal/mol)

(Theo thc nghim, ATP nh NL nhiu t tu k pH mt v [ATP]. Trong k th/t cc m, cc kh/vc trong 1 TB, k pH, p v [ATP] c th khc so vi k chun h/sinh (pH = 7, p = 1 atm, C = 1M), c th 1ATP 10-12 kcal/mol NL t do.

7

9/27/2010

Vai tr ca ATP- ADP trong ch/ho NL:

- Mi dng NL s/hc u c ly t dy cao nng ca ATP - Cht hu c do qt /ho to nn l nhng bnh cha ho nng c chuyn t NL /s m/tri hoc t NL OXH cc cht v c - ATP l mt xich l/h gia cc qt s/sinh NL v cc qt tiu tn NL

2.3. Qu trnh vn chuyn in t 2.3.1. Thnh phn ca chui vn chuyn in t Cc protein gn mng trong ty th c t/chc thnh 4 t hp h/hp ca chui v/c e-. Mi t hp gm 1 s th/vin l protein v 1 s nhm ghp c h/tnh oxy ho kh vi E (th hiu kh) tng dn.

http://www.johnkyrk.com/mitochondrion.html

8

9/27/2010

T hp I: NADH- CoQ reductase T hp II: Succinate - CoQ reductase T hp III: CoQ-Cytochrom c reductase T hp IV: Cytochrom c oxidase

9

9/27/2010

T HP I (NADH-CoQ REDUCTASE- Ch/nng: tch e- t NADH (ca cc dehydrogenase khc nhau, t/ng cho cc c/cht khc nhau) chuyn cho CoQ.

- Cc coenzyme ca t hp I: FMN CoQ C th chuyn 1 hoc 2 e- mt ln (NADH chuyn cng lc 2 e-)

FMN v CoQ ng v/tr truyn e- gia cht cho 2 e- (NADH) v nhng cht ch nhn 1 e- (cc cyt.).

T HP II (SUCCINATE-CoQ REDUCTASE)-Vai tr: chuyn e- t succinate CoQ. - Gm: succinate dehydrogenase v 3 thnh vin k nc kch thc nh. Mt nhm FAD gn qua His vi enzyme, mt chm [4Fe- 4S], hai chm [2Fe - 2S] v mt cyt.b560 th/gia chuyn e- Th hiu redox chuyn e- t succinate CoQ thp, khng NL to ATP (Tuy nhin, y l 1 ca a e- vo chui h hp).

10

9/27/2010

T HP III (CoQ CYTOCHROM C REDUCTASE- Vai tr: chuyn e- t CoQ.H2 (dng kh) sang cyt.c - Gm 2 cyt.b, 1 cyt.c1 v 1 chm [2Fe-2S] Cu to ca cytochrom: - L protein cha hem, trong st th/i h/tr khi nhn v nh e-

- Cyt.c gn lng lo trn mt ngoi ca mng trong ty th, khi th bm vo cyt.c1 ca t hp III, khi th bm vo t hp IV. cyt.c l con thoi chuyn e- gia t hp III v IV.

T hp IV (Cytochrome c oxydase):- V/tr: tch ln lt 4e- t 4cyt.c dng Fe2+ chuyn cho oxy (O2) to 2H2O (H+ ly t cht nn): 4 cyt.c Fe2+ + 4H+ + O2 4 cyt.c Fe3+ + 2H2O

2.3.2. S vn chuyn in t trong chui h hp Da vo Eoca mi thnh vin, thy chiu hng d/chuyn ca e- trong chui: Eo cng thp (cng m), kh/nng nh e - cho thnh vin c tr s cao hn cng mnh ( Eo cng thp, tnh kh cng cao). Eo cng cao, kh/nng tip nhn e-(tnh OXH) cng mnh.

11

9/27/2010

2.3.3. Q/trnh phosphoryl ho oxy ho tng hp ATP S tng hp ATP t ADP + Pi l p..thu NL, ngun cung cp ly t qu trnh vn chuyn e- chui h hp.

Thuyt ho thm thu (Peter Mitchell, 1961): Nng lng t do ca s vn chuyn e - c bo tn do H+ c bm t cht nn ty th ra khong khng gian gia 2 mng v to thnh gradient in ho proton qua mng trong ty th. Sau , th nng in ho ny c dng tng hp ATP.

12

9/27/2010

S gii thch quan im ca P. Mitchell: Qu trnh vn chuyn e- lm H+ b y t cht nn ra khong gia 2 mng, to nn mt chnh lch nng v in tch, gp li l 1gradient in ho H+. Khi gradient in ho ny b ho gii do H+ quay v cht nn qua t hp V (ATP- synthase) th ADP + Pi ATP.

13

9/27/2010

S tng hp ATP:T hp ATP- synthase dn H+ (cn gi l F1FoATPase) lm n/v to ra ATP nh NL ca gradient in ho proton C/trc hnh nm, bm trn mt mng trong, hng v cht nn

C ch tng hp ATP: Chia thnh 3 pha: Dch chuyn proton: Fo thc hin Xc tc s hnh thnh lin kt phosphoanhydride ca ATP: F1 thc hin Hp din gia s trt tiu gradient H+ v tng hp ATP cn s tng tc gia F 1 v Fo. F1 c 3 tiu phn xc tc. Mi tiu phn mt trng thi cu hnh khc nhau:

Trng thi L (loosly): gn c cht v s/phm mt cch lng lo Trng thi T (tightly): gn cht Trng thi O (open): hon ton khng gn

14

9/27/2010

C ch tng hp ATP:1 2 3

NL gi/phng khi H+ chuyn ngc li cht nn lm chuyn i 3 tr/ thi trn ATP ch c t/hp tr/thi T v ATP ch c g/phng tr/thi O.

Phn ng c 3 bc:1. Gn ADP v Pi vo trng thi L 2. S b/i cu hnh do NL t do gy ra lm bin i trng thi LT; ATP c to thnh. Hai tiu phn khc cng thay i cu hnh: T cha ATP thnh O v O thnh L. 3. ATP c t/hp tr/thi T ca mt tiu phn, trong khi 1ATP c tch ra t tr/thi O ca mt tiu phn khc. NL t do gii phng c cung cp nh s dch chuyn H+ l nguyn nhn chnh lm g/phng ATP mi c tng hp khi enzim: lm trng thi T trng thi O.

15