Whether a molecule is oxidized or reduced in a redox reaction depends on its reduction potential relative to the available electron donors and acceptors present that the organism can utilize. Given the following reduction potentials for various redox half reactions, in a lithotroph capable of utilizing ammonia as an energy source, which substances would be potential terminal electron acceptors for respiration?

Both O2 and NO3 are possible electron acceptors.

Explanation:

Respiration with oxygen and some times nitrates as a terminal electron acceptor generates more energy than respiration with other terminal electron acceptors.

This plays out in anaerobic form of respiration when oxygen switches to nitrate respiration when oxygen is depleted but that denitrification in their preferred respiration pathway. Their metabolic adaptations allow some species to grow larger than predicted by cell physiology of aerobic organisms due to oxygen limitation. Nitrate is an important macronutrient, and denitrification is the main oceanic nitrate sink. Several postulations too can help to constrain biogeochemical models for marine nitrate cycling.

they deliver oxygen to the blood