lecture 7- hemoglobin/myoglobin Flashcards
40-50 % percent of blood volume is made of what
red blood cells = hematocrit
what is the partial pressure of oxygen in the atmoshphere?
160 mmhg
where is myoglobin found?
in the cytosol of the muscle
doping ( erthyopoietin, transfusions, high altitude) all have danger in what? and why?
stroke..increases the visocity of the blood, make it hard to get through capillaries
myoglobin stores for delivery to where?
mitochondria and metabolism
what two other things are transported by hemoglobin?
NO and CO2
what does NO do?
relaxation of muscle
explain structures of, and percent of similarities,
proteins look very similar, however have different amino acid seqeucnes. only have leas than 25% amino acid homology
which letters represent the alpha helical regions? in myoglobin
A-H
70% of alpha helices are in what form?
rod like
rod like characteristic of alpha does what?
provides stability, and hold on to prosthetic group
N terminal starts with what letter?
A
which amino acid aid in binding oxygen? and what are their names?
histidine . E7, F8
what provides reserve supply of oxygen?
myoglobin
how many major helical segments in myoglobin?
eight
four of the helices are terminated by thwat residues?
proline
what are the charged proteins in myoglobin
histidine
what is the prosthetic portion?
ferroprotoporphyrin heme group
what stabalizes the iron bond to molecular oxygen?
resonacne delocalization of the electron in the porphyrin ring
oxygen does what to the ferrous group?
oxidizes it into ferric
hemoglobin becomes what when ferrous becomes ferric?
methemoglobin
which histidine dontates bond to oxygen?
E7, distal histideine
ferrous group is coordinated to hoe many ligands or binding groups?
6
oxygen binding curve for myoglobin is what shape?
hyperbolic
what is the oxygen concentration in the capillaries?
20-30 mmhg
myoglobin adjacent to capillaries is nearly what?
saturated
what is the particlal pressure of oxygen at 50% saturation of the myoglobin?
2 mmhg
what is the principal hemoglobin in adults?
hemoglobinm A1
hemo globin is what type of graph? and what is it due to?
cooperativity sigmoidal
when oxygenated hemoglobin moves to tissues wihth partial pressure of 20 mmhg the saturation level of hemoglibin drops to what? what percent of potential oxygen binding sites contribute?
32% 66%
the binding of the first oxygen molecule to each hemoglobin molecile enhances the binding of the second oxygen molecule by a facor of what?
3
when 3 oxygens are bonded to a hemoglobin, what is the affinity for the fourth oxygen molecule?
20 times that of full deoxy
the strongest contacts are between which two things?
alpha and beta
how far does iron move upon oxygenation?
.4
on oxygenation, what is the rotation between alpha one and beta one?
15 degrees
BPG stabailizes what?
the deoxy form of hemoglobin
hydrogen atoms, and carbon dioxide all favor what?
the deoxy form
histidine beta 143 is replaces by what in fetal hemoglobin?
serine
who do fetal hemoglobin have a higher affinity for oxygen than maternal?
the replacing of histidine with serine, decreases affinity for BPG, and therefor binds oxygen more readily
what is the prinicipal hemoglobin in fetal? consisting of which chains?
hemoglobin F. 2 alpha and 2 gamma
as you increase the PH, what happens to oxygen affinity?
as decrease PH, you decrease oxygen affinity
what is the haldane effect?
deoxygenation of the blood increases its ability to carry carbon dioxide
how does a oximeter measure pulse?
measuring absorption of hemoglobin and myoglobin. they absorb diff wave lengths
is full oxygenated hemoglobin diamagnetic or para? magnetic or non
dia. non
is deoxy diamagnetic or para? magnetic or not?
para. magnetic
how does magnetic resonance imaging work?
measures amount of diamagtnetic and paramagentic in brain to see which part is working.
sickle cell anemia causes what as far as dental work
block capillaries and rupture, inflammation, pain, poor bone development, gingival lesions, caries, perio, anema, infections, renal failure
sickle cell is caused by what?
a change from glutamate to a valine in position 6 on the neta 1 strand
what do sickle cells tend to do in blood?
aggregate together forming long fibers, causing hydrophobic interactions
does sickle cell have a higher or lowe PI than normal hemoglobin?
higher
what is thalassemia cause by?
caused by loss of single hemoglobin chain, leading to low levels of functional hemoglobin, and decreased production of red blood cells leading to anema
alpha thalessemia causes loss of what?
cooperativity
