What molecule is indicated by the letter D?

What molecule is indicated by the letter D?

A) ATP

B) Water

C) Glucose

D) Oxygen

Answer. D) Oxygen

Oxygen constitutes a diatomic molecule, symbolized by O2 and happens to be a combination of two oxygen atoms held by covalent bond which is a double bond. It is a non-colored, non-smelling and nearly tasteless gas that together with all the pivotal processes in which it is involved. Oxygen is necessary for respiration, which is the processes in the presence of which cells prove the nutrients into energy and oxygen required to survival by the living organisms. This process is also relevant to combustion reactions, when it unites with the fuels to produce heat or light in the form of a chemical reaction. Oxygen represented with 21% of all components of atmosphere in the Earth which makes breathable for living creatures means that it primary important molecule in many ways seen in biology, chemistry and environmental science.