Transcript CHMI 2227E Biochemistry I

CHMI 2227E
Biochemistry I
Proteins:
-
Quaternary structure
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
hydrophobic
hydrophilic
Porin: a trimeric membrane-bound protein
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
Hemoglobin
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
Hemoglobin HbA vs myoglobin
HbA
Myoglobin
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
Oxygen binding by Hb and myoglobin
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
Oxygen binding by Hb and myoHb
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
Oxygen binding by Hb and myoHb
B
A
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
Oxygen binding by Hb and myoHb
B
A
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
O2 binding changes the 3-D shape of Hb
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
O2 binding changes the 3-D shape of Hb
http://upload.wikimedia.org/wikipedia/commons/0/07/Hb-animation2.gif
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
Hb is an allosteric protein
O2 O2
O2 O2
O2
O2
O2
O2
O2
O2
O2 O2
O2 O2
Low affinity
High affinity
Saturated
CHMI 2227 - E.R. Gauthier, Ph.D.
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Quaternary structure
Why Hb is allosteric, while Myoglobin is not?
CHMI 2227 - E.R. Gauthier, Ph.D.
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The Bohr effect
http://www.aw-bc.com/mathews/ch07/fi7p16.htm
CHMI 2227 - E.R. Gauthier, Ph.D.
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Gas exchange
In the tissues
H2O
Glucose + O2
CO2
Carbonic
anhydrase
CO2
H2CO3
H2O + Cl-
Hb-4O2
H+
HCO3-
HCO3(to lungs)
ATP
Hb-H+
4O2
4O2
Erythrocytes
Plasma
CHMI 2227 - E.R. Gauthier, Ph.D.
Tissues
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Gas exchange
In the lungs
H2O
CO2
CO2
CO2
Carbonic
anhydrase
H2CO3
Air
H2O + Cl-
Hb-4O2
H+
HCO3-
HCO3-
Hb-H+
4O2
O2
Erythrocytes
Plasma
CHMI 2227 - E.R. Gauthier, Ph.D.
Lungs
O2
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