Gas Exchange

Question 1

What happens at tissue?

Answer 1

• 02 moves down concentration gradient to tissue
• CO2 moves in binds haemoglobin directly (Haldane effect)
• CO2 binds water

CO2 + H20 = H2CO3 which dissociates to H +Co3.

The bicarbonate leaves (Cl- shift) and H+ binds haemoglobin to displace O2

The net effect is 02 gets to the tissues

Question 2

What happens in the lungs?

Answer 2

• 02 moves down its concentration gradient and displaces CO2 (Haldane effect)
• Bicarbonate comes back in and binds with displaced H+ to form CO2 + H2)

Net effect is O2 in and CO2 out