Flashcards
Transport of oxygen
Flashcards do conjunto (19)
- 1what is oxygen carried by?haemoglobin
- 2where can haemoglobin be found?erthyrocytes contain millions of molecules of haemoglobin (Hb)
- 3what is the structure of haemoglobin?Hb= protein
made of 4 polypeptides (quarternary)
each contains a prosthetic group containg iron ions, called the haem group
haem groups are found within globin - 4in haemoglobin, what holds the polypetides together?hyrogen bonds
- 5what does haemoglobin display for a gas involved in ventilation?affinity for oxygen
- 6what does the affinty haemoglobin shows for oxygen depend on?location
- 7at the lungs, what kind of affinity for O2 does Hb display?high affinity - strong attraction
- 8at respiring tissues, what kind of affinty does Hb display for O2?eg muscles, Hb has a low affinity for O2 and releases it
- 9what is the % constitutent of atmospheric gases?CO2 = 0.03-0.04%
O2 = 20%
Nitrogen = 78%
Others include water vapour and inert gases - 10what is determined by the % constituent of atmospheric gases? give an example and unitspressure determined by the atmospheric gases
O2 contribues 1/5 partial pressure (pp)
measure in mm of mecury (mmHg) - 11how many haem groups does one Hb molecule have?4
- 12how many atoms of O2 can one molecule of Hb carry?8 atoms of O2.
Each haem group can carry one O2 molecule, therefore 8 atoms in total as there are 4 haem groups per Hb. - 13What is the effect on Hb as each O2 molecule binds with the haem groups?-1st O2 will take time to bind to a haem group
-this alters the shape of the Hb so the next 2 O2 molecules bind quickly
-at this point, the Hb is 75% saturated, 4th O2 will take time to find the free haem group, therefore the dissociation curve is less steep. - 14as muscles respire, what is the product and what happens to the product?creates CO2 and H2O which diffuse out of tissue and into the red blood cell
- 15once CO2 and H2O are in the red blood cell what do they combine to form?carbonic acid
- 16what enzyme do red blood cells have that catalyses the reaction that produces carbonic acid?carbonic anhydrase
- 17as carbonic acid is weak and dissociates easily what happens?dissociates into hydrogen ions (H+) and hydrogen carbonate ions (HCO3-)
- 18what effect does the prescence of H+ have on the pH of the red blood cell and what happens as a result of this?Prescence of H+ reduces the pH
Causes the release of oxugen from the oxyhaemoglobin (HbO8) - 19due to the release of oxygen from oxyhaemoglobin (HbO8) what happenes to the carbon dioxide?carbon dioxide is returned to the lungs as hydrogen carbonate ions and some carboxyhaemoglobin
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- International Baccalaureate Biology (Ventilation) FlashCards sobre Transport of oxygen, criado por Lauren Parker em 09-05-2021.
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- Lauren Parker
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