Answer:
In both cases, the person is deprived of ATP source as the aerobic cellular respiration comes to halt.
Step-by-step explanation:
At higher altitudes, low oxygen pressure deprives the cells of oxygen to serves as the terminal electron acceptor. In the absence of molecular oxygen, electron transport from NADH and FADH2 to O2 can not generate the proton concentration gradient required for ATP synthesis.
Cyanide poisoning also stops ATP synthesis by inhibiting the electron transfer from cytochrome oxidase to oxygen. Cellular respiration is a source of ATP for living aerobic cells. In the absence of ATP synthesis, the person is deprived of energy sources and feels weakness, dizziness, confusion, and shortness of breath.