why oxygen is selected as respiratory gas?

Answer 1

In a biology textbook, look up the chemistry of aerobic respiration.
You will notice that as a result of glycolysis there are a pair of hydrogen atoms released (oxidation). The hydrogen atoms ionize and the protons are carried by hydrogen acceptors (reduction) . The electrons are carried by coenzymes of the electron transport system.
Pairs of electrons are carried along the electron transport
system (ETS)generating ATP for energy. At the end of the ETS, the protons unite with the electrons forming hydrogen. Since excess free hydrogen in a cell is toxic, the incoming oxygen molecules combine with the hydrogen forming water, a waste material of respiration, which is exhaled. Therefore ,the function of oxygen in respiration is to be the final acceptor of hydrogen.
Conveniently, approx. 1/5 of the atmosphere is composed of this gas.

Answer 2

well O2 is the only gas that can react with haemoglobin and a sufficient amount of energy is used to break the bond.
4 O2 + Hb gives u Hb08.

well ders also pollutants which react with haemoglobin but they are harmful and different.

secondly for we land animal(includin us) O2 is used as oxidiser to give energy.

as for aquatic O2 is used coz most probabely it is soluble in water and the same reason for energy

for plant O2 is used to synthetize carbohydrate molecules.

i think that y O2 is chosen as the respirator gas.,

Answer 3

Its sticky without being too sticky. What I mean is, it has just the perfect amount of electrons so that it can easily bond to things and those bonds are easily broken by the amounts of energy our body uses. It is also a gas and abundant.

Answer 4

cos it is only oxygen which can oxidise the food to relese energy from the food,which we require for various reasons.

Answer 5

since it bonds with haemoglobin in our blood to carry energy