Myoglobine hmoglobine 153 aas 2 2 141 aas
![Myoglobine <> hémoglobine α 153 aas α 2β 2 α 141 aas Β 146 Myoglobine <> hémoglobine α 153 aas α 2β 2 α 141 aas Β 146](https://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-1.jpg)
Myoglobine <> hémoglobine α 153 aas α 2β 2 α 141 aas Β 146 aas 18 % d’identité
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![hydrophobe 8 (α loop α) (A>H) Domaine globine hydrophobe 8 (α loop α) (A>H) Domaine globine](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-3.jpg)
hydrophobe 8 (α loop α) (A>H) Domaine globine
![Structure Tétrapyrrolique Structure Tétrapyrrolique](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-4.jpg)
Structure Tétrapyrrolique
![Protoporphyrine IX His O 2 ---His Fe: 6 orbitales D Fixation de O 2 Protoporphyrine IX His O 2 ---His Fe: 6 orbitales D Fixation de O 2](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-5.jpg)
Protoporphyrine IX His O 2 ---His Fe: 6 orbitales D Fixation de O 2 = oxygenation
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Groupement acide propionique
![Indépendance des 4 hèmes Indépendance des 4 hèmes](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-11.jpg)
Indépendance des 4 hèmes
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![O 2 Gaz hydrophobe>> peu soluble Mb et Hb servent de transporteurs O 2 Gaz hydrophobe>> peu soluble Mb et Hb servent de transporteurs](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-15.jpg)
O 2 Gaz hydrophobe>> peu soluble Mb et Hb servent de transporteurs
![Fraction sites occupés/ Sites totaux Fraction sites occupés/ Sites totaux](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-16.jpg)
Fraction sites occupés/ Sites totaux
![Pourquoi structure quaternaire ? ? Hb acquiert des propriétés plus complexe que la myoglobine Pourquoi structure quaternaire ? ? Hb acquiert des propriétés plus complexe que la myoglobine](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-17.jpg)
Pourquoi structure quaternaire ? ? Hb acquiert des propriétés plus complexe que la myoglobine - son affinité est adapté à l’état de l’environement (interaction de molécules) Proton (effet Bohr) 2, 3 BPG
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![Anhydrase carbonique carbaminohemoglobine Anhydrase carbonique carbaminohemoglobine](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-19.jpg)
Anhydrase carbonique carbaminohemoglobine
![Transport du CO 2 -Transport isohydrique (70 -80%) HCO 3 - (anhydrase carbonique) -Transport Transport du CO 2 -Transport isohydrique (70 -80%) HCO 3 - (anhydrase carbonique) -Transport](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-20.jpg)
Transport du CO 2 -Transport isohydrique (70 -80%) HCO 3 - (anhydrase carbonique) -Transport par l’hemoglobine carbamino-hemoglobine -Hb. NH 2 +CO 2>>>>>HBNHCO 2 - + H+
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![Protéines allostériques Coopérativité dans l’interaction de l’oxygène Protéines allostériques Coopérativité dans l’interaction de l’oxygène](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-22.jpg)
Protéines allostériques Coopérativité dans l’interaction de l’oxygène
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![Figure 5. 2 Champe et al, 3 rd edn Substrate binds to enzyme’s active Figure 5. 2 Champe et al, 3 rd edn Substrate binds to enzyme’s active](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-30.jpg)
Figure 5. 2 Champe et al, 3 rd edn Substrate binds to enzyme’s active site, where it is converted to product. glucose Hexokinase crystal structure note relative size of enzyme and substrate Note how structure changes on substrate binding
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![What an enzyme does E+S ES EP E+P The enzyme (E) binds substrate (S) What an enzyme does E+S ES EP E+P The enzyme (E) binds substrate (S)](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-32.jpg)
What an enzyme does E+S ES EP E+P The enzyme (E) binds substrate (S) and converts it to product (P). Note that E recycles. Overall, S P
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![Rate of an enzymatic reaction as a function of temperature and p. H Rate of an enzymatic reaction as a function of temperature and p. H](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-35.jpg)
Rate of an enzymatic reaction as a function of temperature and p. H
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![Km – a measure of E-S affinity • Km = [E]. [S] [ES] • Km – a measure of E-S affinity • Km = [E]. [S] [ES] •](http://slidetodoc.com/presentation_image_h2/f496bdec69da8de281b3b3a181148d23/image-40.jpg)
Km – a measure of E-S affinity • Km = [E]. [S] [ES] • When E is ½ saturated with S (vo= ½ Vmax) • Then [ES] = [E] • and Km = [S] • Units are M (mol/l) Km is the substrate concentration at which vo = ½ Vmax. low Km = high affinity high Km = low affinity
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