Chapter 15 Study Questions (Pt. 2) Flashcards
what does Hb stand for?
hemoglobin
what is hemoglobin?
a protein in red blood cells that carries oxygen from the lungs to the body’s tissues
what is Hb composed of?
4 globin proteins
4 heme chemical groups
what is the function of the heme chemical group?
heme holds iron, iron captures O2
what is the function of the globin protein?
prevent Fe+2 from further oxidation to Fe+3
how do globin proteins prevent Fe+2 from further oxidation to Fe+3?
Fe+2 and +3 can bind O2, but Fe+3 isn’t reversible.
to make sure that the reaction stays reversible, globin protein prevents Fe+2 from losing another electron and becoming Fe+3.
what is cooperative binding ?
once one subunit binds, the rest do too –> peer pressure
what is cooperative binding of O2 to hemoglobin? (2)
- Hb changes from tense to lax conformation
- enhances O2 binding at all 4 hemoglobin subunits
tense state of globin = binds or doesn’t bind O2?
doesn’t bind O2.
relaxed state of globin = binds or doesn’t bind O2?
binds
what are the two states globin can be in?
relaxed and tense
which state do the four globin proteins want to be in? why?
all tense or all relaxed.
a mix isn’t easy to maintain / stable
how does the relaxed state of hemoglobin promote O2 binding?
Fe+2 within the heme group is more accessible to O2 in relaxed state.
why do we call is hemoblogin?
cause it’s made up of heme groups and globin proteins! not a joke.
when old RBCs are recycled and hemoglobin is broken down, what happens to the globin protein?
recycled to reuse the amino acids
when old RBCs are recycled and hemoglobin is broken down, what happens to the heme chemical group?
some is reused, rest is catabolized to bilirubin. body wants to get rid of bilirubin.
when old RBCs are recycled and hemoglobin is broken down, what happens to the globin protein and heme chemical group?
globin: recycled to reuse the amino acids
heme: some is reused, rest is catabolized to bilirubin. body wants to get rid of bilirubin.
the body wants to get rid of bilirubin. who does it?
liver
what is the potential negative impact of infant hyperbilirubinemia?
permanent brain damage
how is infant hyperbilirubinemia treated in newborns?
phototherapy forms a bilirubin isomer that is more water soluble and therefore more easily removed by the liver
in treating infant hyperbilirubinemia, phototherapy forms a bilirubin isomer that is more water soluble. why is the new form more water soluble?
hydrophilic group is closer to the outside and more accessible than in the original conformation
what is bilirubin? how is it removed from the body?
a waste product of red blood cell breakdown. it is removed from the body in bile.
what is infant hyperbilirubinemia? what causes it?
a condition in which a newborn’s blood contains too much bilirubin.
normally, the liver removes bilirubin. when it doesn’t bilirubin levels in the blood may rise.
