How many molecules of $H_2CO_3$ are formed due to the presence of carbonic anhydrase in the cytoplasm every second?

Binding of $O_{2}$ with haemoglobin is primarily dependent upon:
$I.$ Partial pressure of $O_{2}$
$II.$ Partial pressure of $CO_{2}$
$III.$ Hydrogen ion concentration
$IV.$ Temperature
Choose the correct option.

In blood,$CO_2$ is mainly transported through

If $ppCO_2$ is high and pH is low,then it will result in:
$i$. increase in affinity of haemoglobin for $O_2$
$ii$. decrease in affinity of haemoglobin for $O_2$
$iii$. oxygen dissociation curve shifts to left
$iv$. causes release of $O_2$ for diffusion into tissue cells
$v$. $H^+$ and $HCO_3^-$ ions combine to form carbonic acid

The majority of carbon dioxide produced by our body cells is transported to the lungs as

By whom and in what amount does the transport of gases occur during respiration?