Transport of carbon dioxide in the blood

Question 1

Does arterial blood contain more oxygen or more carbon dioxide?

Answer 1

More carbon dioxide

Question 2

What are the different forms of carbon dioxide in the blood?

Answer 2

Dissolved

Reacted

Bound to haemaglobin

Question 3

What are the different forms of carbon dioxide in the blood from most common to least common?

Answer 3

Reacted

Bound to haemoglobin

Dissolved

Question 4

What does dissolved carbon dioxide in the plasma do?

Answer 4

Some of it reacts

Some of it diffuses across red blood cell membranes into red blood cells

Question 5

How does carbon dioxide react in the plasma?

Answer 5

Carbon dioxide + water carbonic acid

Question 6

What does carbonic acid do in the plasma?

Answer 6

Carbonic acid bicarbonate + hydrogen ion

this occurs very quickly

Question 7

What does dissolved carbon dioxide in red blood cells do?

Answer 7

Some of it reacts

Some of it binds to haemaglobin

Question 8

How does dissolved carbon dioxide in red blood cells react?

Answer 8

Carbon dioxide + water bicarbonate + hydrogen ion

Question 9

What enzyme catalyses the reaction

carbon dioxide + water bicarbonate + hydrogen ion?

Answer 9

Carbonic anhydrase

Question 10

What effect does carbonic anhydrase have on the reversible reaction
carbon dioxide + water bicarbonate + hydrogen ion?

Answer 10

Increases the rate of both the forward and backward reactions equally

Question 11

What happens to bicarbonate ions in red blood cells?

Answer 11

AE transports bicarbonate ions from the red blood cells into the plasma
and chloride ions from the plasma into the red blood cell

Question 12

How does carbon dioxide bind to haemaglobin?

Answer 12

Binds to amine groups of globin chains

Question 13

What is the reacted form of carbon dioxide?

Answer 13

Bicarbonate ions

Question 14

What is the name of carbon dioxide bound to haemaglobin?

Answer 14

Carbaminohaemaglobin

Question 15

What happens to pCO2 at tissue capillaries? Why?

Answer 15

Increases

because tissue metabolism produces CO2

Question 16

What happens to the amount of carbaminohaemaglobin at tissue capillaries? Why?

Answer 16

Increases

high pCO2 causes oxygen to be released from haemaglobin by Bohr effect
carbon dioxide binds to it

Question 17

What happens to the amount of bicarbonate ions at tissue capillaries? Why?

Answer 17

Increases

because haemaglobin in its tense state
more hydrogen ions bind to it
favours forward reaction
more bicarbonate ions produced
more transported into plasma

Question 18

What happens to pCO2 at pulmonary capillaries? Why?

Answer 18

Increases

because of the Haldane effect

Question 19

What is the Haldane effect?

Answer 19

Binding of oxygen to haemaglobin
causes carbon dioxide to be released from haemaglobin

also puts haemaglobin in its relaxed state
fewer hydrogen ions bind to it
favours backwards reaction 
more carbon dioxide produced 
diffuses into plasma

Question 20

What happens to carbaminohaemaglobin at the pulmonary capillaries?

Answer 20

Dissociates into haemaglobin and carbon dioxide

Question 21

What happens to the increased carbon dioxide at the pulmonary capillaries?

Answer 21

Diffuses into the alveoli

expired from the alveoli