Carbon dioxide affects o2binding to hb by: a) co2forming iron carbonate with the heme-iron atom. b) hb competing with carbonic anhydride for co2. c) directly binding to heme-fe in the oxygen binding site of hemoglobin. d) forming hco3- that combines with h+ to increase co2binding. e) forming h+ hco3- where the h is an antagonist to oxygen binding to hb.

The correct answer is c) directly binding to heme Fe in the oxygen binding site of the hemoglobin.

Explanation:

Carbon dioxide is the waste product of cellular respiration.Carbon dioxide bind to hemoglobin to form carbaminohemoglobin in which the hemoglobin exist as T state or Tensed state.

        Carbon dioxide interact with the oxygen binding site of hemoglobin thus decreasing the affinity of hemoglobin for oxygen.