Why do animals need to take in oxygen? A) to break down fuel molecules

B) to keep less oxygen in the atmosphere

C) to build fuel molecules from carbon dioxide

D) to be able to use energy from the sun

I think the answer is A

maritime tropical may be your answer.

cellular respiration oxidizes food into energy in the form of atps.

glycolysis (6 c hexose) > 2x atps are used > 6c hexose biphosphate > 2 x 3c triphosphate >

2 x 3c pyruvate (2x nadh produced from nad) and (4x atp produced)

pyruvate actively pumped mitochondrial matrix.