Myoglobin and Hemoglobin

myoglobin

stores O2 in muscles

hemoglobin

component in red blood cells, trnasports oxygen from lungs to tissues

which has a sigmoidal curve when graphed?

hemoglobin

which has a hyperbolic curve when graphed?

myoglobin

what is Kd?

dissociation constant

what does a large Kd mean?

weak binding

what does a small kd mean?

strong/tight binding

what is saturation and what axis is it on in the oxygen binding graphs?

• tells us what number of proteins is bound to oxygen

• on y-axis

what is partial pressure of O2 and what axis is it on?

• the concentration of oxygen

• on x-axis

binding affinity

how weak/tight a protein binds to oxygen

cooperative binding

when binding of O2 at one sit on hemoglobin makes other unoccupied sites more likely to bind O2 and vice versa

does myoglobin or hemoglobin bind oxygen cooperatively?

hemoglobin which makes it a good O2 carrier

what does it mean when a hemoglobin curve shifts to the right?

hemoglobin has lower affinity for O2 and will unload easier

what does it mean when a hemoglobin curve shifts to the left?

Hemoglobin has a greater affinity to bind to O2

how is hemoglobin regulated?

molecules inhibit oxygen binding

what are the allosteric inhibitors of hemoglobin?

• BPG

• H+

• CO2

what does an increase in the allosteric inhibitors of hemoglobin lead to?

lower oxygen binding affinity