Question

A diet drug that was popular in the 70s caused rapid fat burn. The drug caused excessive sweating, muscle fatigue and could cause cardiac arrest. It was known to interfere with the mitochondria. What might this drug have been doing to explain its effectiveness in burning fat but also the negative side effects? Be sure to explain your reasoning in terms of specific aspects of mitochondrial function.

Answer 1

A diet drug causes weight loss by uncoupling oxidative phosphorylation mechanism mitochondria, leading to a heightened metabolic rate and increased fat metabolism.

It occurred due to the change in the proton electrochemical gradient, which results in potential energy dissipating as heat, instead of being converted to ATP.

Electron movement from NADH or FADH2 to O2 via the mitochondrial electron transport system generates electrical energy that is partially captured as a transmembrane pH gradient.

The movement of H+ back across the membrane, driven by the electrochemical gradient, is through a channel in the F1ATPase (an F-type primary active transport system discussed above, that is coupled to ATP synthesis.

A diet drug disturbed the H+ gradient before it can pass through the F1ATPase, thus uncoupling electron transport, the energy source for the H+ gradient, from ATP synthesis.

Therefore, in the presence of a diet drug, electron transport continues, even at an accelerated rate, but ATP production is diminished. The energy that should have been converted to chemical energy in the form of ATP is then released as excess heat.

Negative impacts as follows:

The patient became weak due to low ATP levels.

Breathing increased due to increased electron transport to rescue ATP production.

The metabolic rate increased.

Body temperature increased due to the inability to trap electrical energy as chemical energy in the form of ATP, releasing heat.

Bodyweight decreased due to increased respiration burning more stored fat.

It is highly toxic and symptoms are including vomiting, flushed skin, sweating, dizziness, headaches, and irregular heartbeat.