hemoglobin Flashcards
hemoglobin is an ___ protein
allosteric
95% of a red blood cell is ___
hemoglobin
T/F: animals lower than mammals still have a nucleus in their red blood cells
true
Heme is a type of ___ just like chlorophyll.
porphorin
visual/structural difference between oxy and deoxy hemoglobin
Deoxy : has a little white space in the middle of the tetramer
Oxy: no space. When its carrying oxygen, shape shifts, closes.
function of biphosphoglycerate? (BPG)
facilitates the release of o2; does so by stabilizing the T state, plugging itself into the hole in deoxyhemoglobin.
BPG acts as what kind of inhibitor
hetertropic (remember, homotropic would be same substance)
hemoglobin helps animals to be able to bind oxygen in the ___ and deliver it to the ___
lungs, tissues
where is partial pressure of oxygen highest
lungs
where can both myoglobin and hemoglobin pick up oxygen
lungs, due to high partial pressure
The oxygen affinity of fetal red blood cells
The oxygen affinity of fetal red blood cells is higher than that of maternal red blood cells because fetal hemoglobin does not bind 2,3-BPG as well as maternal hemoglobin does. Fetal hb consists of 2 alpha and 2 gamma chains. The gamma chains have lower affinity for 2,3-bisphosphoglycerate than the beta chains of maternal hb.
(recall that BPG facilitates RELEASE of O2)
how does CO2 promote the release oxygen
As CO2 dissolves in tissues, they become slightly more acidic than the lungs.
Low pH allows the formation of ionic interactions -> stabilize T state of hemoglobin -> facilitate oxygen release
is the pH drop the only reason that CO2 in lungs facilitates oxygen release?
no! Since both CO2 and H+ are inhibitors: both affect release of oxygen in the tissues.
Both pH and CO2 have separate effects on hemoglobin causing them to release more oxygen in the tissues. Now we can dump off 88% in tissues and pick up nearly 100% in the lungs.
how is sickle cell anemia caused?
A small mutation that caused a change in one of the hemoglobin chains such that valine was inserted where glutamate should have been. Ends up forming long fibrils instead of a sphere. Sickles the shape of the cell. Still carry oxygen but clog up the capillaries.
oxygen binds to hemoglobin ____
homotropically
