hemoglobin has how many subunits that can bind heme to iron to oxygen?
4
myoglobin has how many subunits?
1
myoglobin vs hemoglobin:
has
... [Show More] higher affinity for oxygen?
myoglobin
_______________ is more saturated with O2 in smaller amounts of O2
myoglobin vs hemoglobin
myoglobin.
oxygen dissociation curve is more steep at first.
when hgb is bound to oxygen, what shape is taken and color?
Relaxed state. planar/linear shape.
color is bright red
when hgb is releasing oxygen to tissues in need what shape is taken and color?
Bent shape, Tense state. blue/purple color
what is deoxyhemoglobin?
hemoglobin without oxygen
the binding of one oxygen molecule to deoxyhemoglobin ______________ affinity of remaining sites on the same hemoglobin molecule?
increases
% hemoglobin that has O2 bound to iron regardless of red cell concentration
hemoglobin saturation, O2 sat/pulse ox
if theres an increase in DPG, temperature and acidity, a _________ shift is seen. hgb has ___________ affinity for oxygen
right
more acid = less affinity for oxygen
if theres a decrease in DPG, temperature and acidity, a _________ shift is seen. Hgb has _____________ affinity for oxygen
left shift.
decreased acidity = increased affinity for oxygen
As DPG increases, what happens to hemoglobin?
it causes increased unloading of oxygen as blood flows through tissues.
causes increased oxygen delivery to tissues.
hemoglobin thats exposed to high PCO2, H+ and temperatures causes it to have _________ affinity to oxygen
decreased affinity. high acid and temp and build up of PCO2 mean that those tissues need oxygen so hemoglobin unloads oxygen. and has decreased affinity (likelihood) of picking up oxygen from those tissues.
which has a higher affinity for oxygen? adult vs fetal hemoglobin?
fetal hgb
effect of CO on hemoglobin?
tight binding of CO to hemoglobin = left shift. this means that hgb affinity for oxygen decreases the unloading of oxygen to tissues.
once CO is bound to hgb it doesnt let go of oxygen in tissues so pulse ox reads high, but tissues arent getting oxygen. bright red/pink color.
relaxed state - all subunits filled up.
more erythrocytes produced and DPG increases causing right shift to facilitate oxygen unloading in tissues, increased muscle myoglobin to increase O2 transfer.
what is happening here?
compensation for high altitudes
how does 100% oxygen help in CO poisoning?
more oxygen to bind to available hgb causing more O2 to be delivered to starved tissues. eventually the CO will displace from Hgb.
what is the Bohr effect?
when hgb responds to changes in pH to deliver oxygen where its needed most
high H+ concentration
acidic, low pH
high OH- concentration
basic, high pH
works by accepting hydrogen ions from solution when in excess and donating hydrogen ions when theyve been depleted
buffer
with more H+, acidic state, lower pH favors ______ state. protons attach to _________ state and have ________ affinity for oxygen
low pH = H+ = tense state.
less affinity for oxygen
deoxygenated hemoglobin
tense state hgb goes back to lungs and picks up O2, drops off CO2 as byproduct. Fewer H+, higher pH favors ________ state and has ___________ affinity for oxygen
relaxed. higher affinity
hgb acts as a buffer to prevent blood from becoming to acidic by binding to:
A- excess H+
B- excess CO2
C- excess bicarb
D- excess oxygen
A excess H+. hgb doesnt bind with CO2.
how does the pH in marathon runners leg muscles during a race compare to the pH in the same tissues at rest?
A. The pH is lower in her leg muscles during the race.
B. The pH is higher in her leg muscles during the race.
C. The pH is the same in both conditions.
A- pH is lower in leg muscle during race. muscle creates CO2 as a byproduct and CO2 is acidic
CO2 + H2O catalyzed by carbonic anhydrase = ____________ and __________ and how does that affect the pH of muscles?
HCO3- and H+.
the H+ causes the pH to decrease and signals the hgb to drop off oxygen at tissue site.
low pH = lower affinity for oxygen = able to drop off oxygen rather than saving it to take it to lungs.
What property of hemoglobin, not observed in myoglobin, enables hemoglobin to be an effective oxygen delivery molecule?
A. Bent shape
B. High iron content
C. Cooperativity
D. Parabolic curve
C - cooperativity.
once 1 subunit of hgb binds to O2, the others want to do it as well because cooperativity brings the subunits closer. [Show Less]