Answer:
NAD+, FAD.
Step-by-step explanation:
The citric acid cycle is popularly known as the Kreb's cycle. The cycle involve the oxidation of acetyl-CoA to produce energy. The Kreb's cycle is a chemical process that produces produces two carbon dioxide molecules,NADH,FADH2 and one ATP.
When oxygen is depleted, the citric acid cycle stops, apart from oxygen NAD+ and FAD could be added to the system to restore citric acid cycle activity. NAD+ acts as an electron acceptor.
Citric acid cycle/Kreb's cycle is an aerobic process that occurs in the mitochondria and produces thirty-six(36) ATPs.