Name the energy currency in the living organisms. When and where is it produced?

During deficiency of oxygen in tissues of human beings,pyruvic acid is converted into lactic acid in the

How are the lungs designed in human beings to maximize the area for exchange of gases?

$(a)$ Name the following:
$(i)$ Part where air is filtered by fine hair and mucus.
$(ii)$ Part which terminates in balloon-like structures.
$(iii)$ Balloon-like structures where exchange of gases takes place.
$(iv)$ Part which separates the chest cavity from the abdominal cavity.
$(b)$ Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms?

Which of the following is most appropriate for aerobic respiration?

How are the alveoli designed to maximise the exchange of gases?