Chapter 17 (Pt. 3) Flashcards
how does temperature affect Hb affinity for O2?
temperature alters structure, thus increase temperature decreases Hb affinity for O2.
when exercising, body temperature increases when making ATP, right shift, lower affinity
how does pH affect Hb affinity for O2?
decreased pH = decreased Hb affinity
how does CO2 affect Hb affinity for O2?
increased metabolic activity = increased Co2
CO2 binds to amino groups
carbamino-Hb assumes “tense-like” state = lower affinity for O2 than Hb did.
binding CO2, not O2 = decreased affinity
how does 2,3 bisphosphoglycerate affect Hb affinity for O2?
2,3 BPG binds to Hb
Hb assumes tense-like state
decreased affinity for O2, can’t stay in relaxed state
how does the Bohr effect affect Hb affinity for O2?
decreased pH = decreased Hb affinity
HOW does carbamino-Hb affect Hb affinity for O2?
increased metabolic activity = increased CO2
CO2 binds to amino groups
carbamino-Hb assumes “tense-like” state = lower affinity for O2 than Hb did.
binding CO2, not O2 = decreased affinity
how does the Haldane effect affect Hb affinity for O2?
increased metabolic activity = increased Co2
CO2 binds to amino groups
carbamino-Hb assumes “tense-like” state = lower affinity for O2 than Hb did.
binding CO2, not O2 = decreased affinity
increased Hb affinity for O2: right or left shift?
left
decreased Hb affinity for O2: right or left shift?
right
right shift: increased or decreased Hb affinity for O2?
decreased
left shift: increased or decreased Hb affinity for O2?
increased
why does a lower pH decrease hemoglobin affinity for O2?
lower pH = more H+
histidine (near C terminus of globin protein) grabs an H+ and gains a full (+) charge
(-) aspartic acid nearby attracts to (+) and locks Hb in “tense-like” state to prevent cooperative binding
less affinity for O2
why does CO2 decrease Hb affinity for O2?
CO2 binds to amino groups at the N terminals of the 4 Hb subunits
and at internal arginine and lysine AAs
Hb conformational change, converted into “tense-like state”
carbamino Hb has a lower affinity for oxygen than Hb
why does 2,3 bisphosphoglycerate lower Hb affinity for O2?
2,3 BPG binds to Hb and locks Hb in a tense-like state
under what conditions does 2,3 BPG activity increase? (3)
low O2 levels.
- anemia
- high altitude
- during pregnancy
why do O2 levels drop in anemia?
not enough RBCs
why do O2 levels drop in high altitude?
not enough O2 to saturate Hb, even if you do have enough RBCs
why do O2 levels drop during pregnancy?
mom is breathing for two
what direction would 2,3 BPG shift the curve of Hb for O2?
right
why is overproduction of 2,3 BPG advantageous under hypoxia conditions?
allows for more O2 to be released and go to hypoxic tissues
non-enzymatic glycation increases/decreases Hb affinity for O2 and increases/decreases O2 delivery to tissues
increases; decreases
