Oxygen dissociation curve shifts towards left due to increase in . . . . . . during internal respiration.

$CO_{2}$ is transported in blood combined with haemoglobin as:

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.

To which part of $Hb$,$CO_2$ binds?

Carbonic anhydrase is found in

What are $P$ and $Q$ in the given reaction?
$CO _2+ H _2 O \underset{Q}{\stackrel{P}{\rightleftharpoons}} H _2 CO _3 \underset{Q}{\stackrel{P}{\rightleftharpoons}} HCO _3^{-}+ H ^{+}$