Mass transport Flashcards
(21 cards)
haemoglobin made up of how many polypeptide chains
4 polypeptides
what gives haemoglobin its red colour
iron ions
loading
haemoglobin binding with oxygen
unloading
haemoglobin releasing oxygen
when and where is oxyhaemoglobin formed
when O2 is loaded onto haemoglobin it forms oxyhaemoglobin where theres a high pO2
where does oxyhaemoglobin unload
where theres a low pO2
in the alveoli why does o2 load onto haemoglobin to form oxyhaemoglobin
because o2 enters blood capillaries at alveoli in lungs and the alveoli has a high pO2
what do cells use when respiring and what does it do
cells use O2 when respiring and it causes the pO2 to lower which is why red blood cells deliver oxyhaemoglobin to respiring tissues causing it to unload O2 (release)
why red blood cells deliver oxyhaemoglobin to respiring tissues
cells use O2 when respiring and it causes the pO2 to lower. red blood cells cause it to unload O2 (release)
where is there a high affinity for O2
at the lungs
reversible reaction for haemoglobin
Hb+4O2<=>HbO8
how does CO2 affect O2 unloading
Hb. gives O2 up easily at high pCO2
what do cells produce
CO2 so that raises the pCO2 increasing rate of oxygen unloading
if theres a high affinity of pCO2 what affect does that have on the dissociation curve
shifts it to the right
role of Hb
transport oxygen
how must haemoglobin be efficient when transporting oxygen
- readily associate with oxygen at the surface where gas exchange takes place
- readily dissociate from oxygen at those tissues requiring it
why do different haemoglobin have different affinities for oxygen
each species produces a haemoglobin with a slightly different amino acid sequence. the haemoglobin of each species therefore has a slightly different tertiary structure and different oxygen binding properties.
what is happened at the gas exchange surface
co2 constantly being removed. the ph is raised due to the low conc of co2. that causes the shape of Hb to change into one that can load oxygen more readily
in tissues co2 is produced by respiring cells. co2 is acidic in solution so what does that do to the ph of blood
its lowered in tissues. that changes the shape of hb into one with a lower affinity for oxygen. hb releases its o2 into respiring tissues
the more active a tissue is the more ___ is ____
the more oxygen is unloaded
the higher the rate of respiration -
the more carbon dioxide the tissue produces so the greater the haemoglobin shape change so its more easily oxygen is unloaded so the more oxygen is available for respiration
