ferrous iron (Fe2+) can form ___ bonds
6 bonds
2 bonds on ach side of the ___ poryphyrin ring
planar poryphyrin ring
myoglobin
in heart and skeletal muscle
- single chain
- O storage; binds one O2 molecule to ferrous iron atom on heme group
non-polar amino acids on the interior
charger AAs on surface
hemoglobin
non-polar AAs line interior and localized regions on exterior
globin genes
chromosome 16
- 3 functional alpha-like genes
chromosome 11
- 5 functional beta-like genes
hemoglobin fetal
two adult alpha2 subunits
two fetal beta subunits
hemoglobin adult
two adult alpha2 subunits
two adult beta subunits
Hbalpha2
most common
gene switching for globin genes
beta-globins
- 2 switches
- embryonic to fetal
- fetal to adult during perinatal period
alpha-globins
- single switch
- embryonic to adult
- occurs verY early
oxygen binding to hemoglobin
4 bonds to N
1 bond to histidine
1 more bond for O
movement of iron mediated by…
proximal histidine in subunits
states of Hb
T - tensed: more interxns w/ subunits
R - relaxed: fewer interxns and more flexible for interactions
oxygenated heme is ____
planar
deoxy is nonplanar
P50
is partial pressure of O2 yielding 50% of hemoglobin
- lower P50, higher O affinity
- lowering the P50 is left shifting
H+, CO2, and DPG are..
negative allosteric effectors of oxygen binding
