haemoglobin (module 3) Flashcards
1
Q
what is the structure of haemoglobin?
A
- quaternary structure
- in red blood cells
- each chain has a haem group attached to it containing an iron ion
- each haemoglobin can carry 4 oxygen molecule
2
Q
what is affinity?
A
the ability of haemoglobin to attract oxygen
3
Q
why does babies have fetal haemoglobin before birth?
A
- fetal Hb has a higher affinity under same partial pressure
- so oxygen can diffuse from mother to fetus
4
Q
why is fetal haemoglobin replaced by adult haemoglobin once a baby is born?
A
- adult haemoglobin has lower affinity so easier unloading of oxygen for aerobic respiration
5
Q
what is cooperative binding?
A
- haemoglobin changing shape when binding to first oxygen
- making it easier for further oxygen to bind to haemoglobin
6
Q
what is the Bohr effect?
A
when the concentration of carbon dioxide causes the oxyhemoglobin curve to shift to right
7
Q
what are the effects of increasing CO2 concentration?
A
- more oxygen dissociation
- decrease haemoglobin affinity
- decrease of pH as acidity increases (forms carbonic acid)
8
Q
when the curve shifts to the left what happens to affinity of hb?
A
- the affinity increases
- easier to bind to oxygen
- occurs in places of lower partial pressures ( high altitudes)
- opposite occurs for curve shift to right
