The second phage of cellular respiration is transition stage.
Process take place in transition stage:
The transition stage take place in mitochondria. The pyruvate is combined with NAD+ to form NADH and acetyl co-enzyme molecules.
After transition stage, Krebs cycle starts.
The brain stem is the answer that you are looking for
An ocean habitat is a large body of salty sea water. There are rocks, sand, mud, and seaweed, where some animals make homes or hide from predators.