I'd go with 'the cells won't be able to produce energy' since oxygen is crucial for cellular respiration and cellular respiration is what releases energy!
Hope it helps! <3
A genus of gram-positive, microaerophilic, rod-shaped bacteria occurring widely in nature. Its species are also part of the many normal flora of the mouth, intestinal tract, and vagina of many mammals, including humans. Pathogenicity from this genus is rare.
hope it helps