Carbon dioxide is transported in the blood in various forms.

a. Describe how carbon dioxide molecules reach red blood cells from respiring cells.

The diagram below shows part of a capillary network and some cells of the surrounding tissue.

b. State three ways in which the blood at Y differs from the blood at X other than in the concentration of carbon dioxide.

An enzyme in red blood cells catalyses the reaction between carbon dioxide and water as blood flows through respiring tissues.

c. i. Name the enzyme that catalyses this reaction.

ii. Explain the significance of this reaction in the transport of carbon dioxide.

d. The graph below shows the effect of increasing the carbon dioxide concentration on the oxygen dissociation curve for haemoglobin.

i. State the percentage saturation of haemoglobin with oxygen at a partial pressure of 5 kPa of oxygen when the partial pressure of carbon dioxide is:

1.0 kPa

1.5 kPa

ii. The percentage saturation of haemoglobin with oxygen decreases as the partial pressure of carbon dioxide increases. Explain how this happens.

iii. Name the effect of increasing carbon dioxide concentration on the oxygen dissociation curve.

iv. Explain the importance of the effect of carbon dioxide on haemoglobin as shown in the graph above.

Transcribed Image Text:

arteriole end venule end X Y