why do we breath oxygen?why not nitrogen!!?

Answer 1

heh, good question, most organisms have evolved to use oxygen in respiration - even plants do it to some degree (during night when they're not carrying out photosynthesis), basically organisms can harness the energy gained from the reaction of oxygen with carbohydrates and other food sources. Respiration is controlled oxidation, and the process is exothermic, and the energy released is used to drive physiological processes.

There is no such reaction with nitrogen since nitrogen is very stable and unreactive. The only way you could get nitrogen to react with food is by putting energy in, which is why it cant be used in respiration.

I suppose that means that any reactive gas could drive reactions that are required for life - potentially life could evolve to breath a gas like chlorine or flourine.

hope this helps

Answer 2

We DO breath nitrogen -- it makes up about 70% of every breath we take.

However, the body does not **metabolize** nitrogen, because that's not the way our body chemistry works -- we use oxygen in the "combustion" of food to make energy. Nitrogen gas, with triply bonded atoms, is too stable to participate in many reactions. That is why we often use a nitrogen "blanket" over specific sensitive reactions to prevent them from getting out of hand.

Answer 3

Nitrogen is not a reactive gas. It is very inert.

Answer 4

cuz god made us breathe in oxygen