XII: Transport of CO2

Question 1

Respiratory exchange ratio definition

Answer 1

Difference between the CO2 I take and what I give out

Question 2

Normal respiratory exchange ratio

Answer 2

0.8

Question 3

% of CO2 dissolved in blood

Answer 3

5% –> 40mmHg –> 2.8mL CO2/100mL

Question 4

Once dissolved in blood,

Answer 4

CO2 reacts w/ H2O to give HCO3- + H+

Carried out by carbonic anhydrase

Question 5

HCO3- corresponds to what % in blood

Answer 5

90%

Question 6

Bohr effect

Answer 6

Dissociation curve shift due to an increase in [CO2] primarly and [H+] secondarily allowing the release of O2 from tissues

Question 7

How does O2 dissociate from tissues

Answer 7

CO2 diffuses into blood
Increase of PCO2 in blood
Shift to the right of the O2-Hb dissociation curve 
Less affinity of Hb for O2 
Dissociation of O2 from Hb

Question 8

How does O2 bind to Hb

Answer 8

CO2 diffuses to alveoli 
Decrease of PCO2 in blood
Shift to the left in O2-Hb dissociation curve 
More affinity of Hb for O2 
Binding of O2 to Hb

Question 9

Haldane effect occurs where

Answer 9

In alveoli, from an increase in PO2 that modifies Hb to release CO2 and H+

Question 10

Bohr effect occurs where

Answer 10

In tissues and is the tendency to give up O2 due to increased PCO2 and H+

Question 11

RELEASE OF CO2 DEPENDS ON

Answer 11

PO2

Question 12

Arterial blood PO2 and PCO2

Answer 12

PO2 - 100mmHg

PCO2 - 40mmHg

Question 13

Venous blood PO2 and PCO2

Answer 13

PO2 - 40mmHg

PCO2 - 45mmHg