8.4 Transport Of Oxygen And Co2 In The Blood Flashcards Preview

8. Transport In Animals > 8.4 Transport Of Oxygen And Co2 In The Blood > Flashcards

Flashcards in 8.4 Transport Of Oxygen And Co2 In The Blood Deck (12)
Loading flashcards...

What is haemoglobin

Red pigment that carries oxygen in the blood
Very large globular conjugated protein made up of 4 peptide chains
They can bind to 4 oxygen molecules


What is positive cooperativity if heamoglobin

The arrangement of haemoglobin means that as soon as one oxygen molecule binds to the haem group the molecule will change shape making it easier for the next oxygen molecule to bind


What do oxygen dissociation curves show

The affinity of haemoglobin for oxygen


Why does the curve on the oxygen dissociation level out

The haemoglobin becomes fully saturated at very high partial pressure of oxygen because all the haem groups are bound to oxygen


What is the effect of co2 on haemoglobin affinity
What effect does it cause

The higher the partial pressure of co2 the more easily the haemoglobin gives up oxygen
Causes the Bohr effect


What is the importance of the Bohr effect

In active tissues with a High pp of co2 haemoglobin gives up 02 easier
In lungs where the pp of co2 is low, oxygen binds to haemoglobin easier


How do fetus get oxygen

Fetal haemoglobin has a bigger affinity of oxygen than adult haemoglobin
Therefore it removes oxygen from the maternal blood as they move past each other in the placenta


How is co2 transpired from the tissue to the lungs

5% is carried dissolved in the plasma
10-20% is combined with amino groups in polypeptide chains of haemoglobin
Forming carbaminohaemoglobin
75-85% is converted into carbonate ions in the cytoplasm of red blood cells


How does carbon dixode turn to hydrogen carbonate ions

Co2 reacts slowly with water to form carbonic acid
This carbonic acid dissocties to form hydrogen ions and hydrogen carbonate ions


What enzymes are there in the red blood cells that catalyse the reaction between co2 and water to from
Carbonic acid

Carbonic anhydrase


What is the chloride shift

Negatively charged hydrogen carbonate ions move out is the cell red blood cells into the plasma by diffusion
The negatively charged chloride ions move into the red blood cells which maintains the electrical balance of the cell


How do the hydrogen carbonate ions convert back to co2 when it reaches the lung tissue

Carbonic anhydrase catalyse the reverse reaction breaking down carbonic acid into co2 and water
Hydrogen carbonate ions diffuse back into the erythrocytes and react with hydrogen ions to form more carbonic acid
Thus releases free co2 which diffuses into the lungs