K.C.S.E Biology Q & A - MODEL 2014PP2QN02

K.C.S.E Biology Q & A - MODEL 2014PP2QN02

The diagram below illustrates the role played by red blood cells in the transportation of carbon (1V) oxide.

​(a) Other than the carbon (IV) oxide transportation in the red blood cells, name the other form of carbon (1V) oxide transportation in humans. 
(b) (i) Name substance F 
(ii) Name the enzyme marked C and state its role in the reaction. 
Enzyme 
Role 
(c) Explain why transportation of carbon (1V) oxide in red blood cells is advantageous. 
(d) Explain the role of calcium ions in blood clotting. 

ANSWERS

​(a) Carbonic acid/carbaminohaemoglobin/hydrogen carbonate;
(b) (i) Water;
(ii) Carbonic acid; 
Role: catalyses reaction between carbon IV oxide and water to form (weak) carbonic acid; 
(c) Prevents accumulation of acidity/maintains pH of blood since hydrogen ions combine with haemoglobin to form Haemoglobin acids;
Faster; due to the catalytic effect of carbonic anhydrase; 
(d) Activates thromboplastin; thrombokinase to neutralize heparin/convert prothrombin to thrombin;