Chapter 5 Flashcards
ligand
molecule reversibly bound by protein
Why is CO deadly?
competes with oxygen for binding to heme
myoglobin structure
single polypeptide of 153 residues arranged in 8 a-helices
Mb P50?
3 torr
Hb P50?
30 torr
Partial pressure ________ as you move away from lungs
decreases.
R-state
active
T-state
inactive
allosteric modulators/effectors
activators or inhibitors and bind to allosteric proteins at sites separate from functional binding site
heterotropic interaction
modulator is different from normal ligand
Oxygen is a _______________________ of hemoglobin
homotropic allosteric activator
oxygen binding promotes …..
R state
Which has higher O2 affinity…. R or T state?
R state
bisphosphoglycerate
decrease Hb affinity for oxygen
-heterotropic allosteric inhibitor of Hb
BPG
carries 5 units of negative charge and binds to the positively charged pockets of Hb
binding of BPG by Hb governed by…
electrostatic interactions
sickle cell anemia
changes properties red blood cells to rigid and no flexibility to squeeze in capillaries … blocking blood flow
sickle cell anemia fibers
form in capillaries where oxygen is lowest, blocks blood flow to extremities
malaria infects…
decreases pH in red blood cells, causes release of oxygen
some invertebrates use _______ instead of Hb
hemocyanin
hemocyanin uses…
copper rather than iron
