A new antibiotic is produced that inhibits the synthesis of acetyl-CoA and the electron transport chain in bacteria. For each glucose molecule that is metabolized, how many fewer ATP molecules will be produced? 4 38 34 2 36

The correct answer is 36 fewer ATP molecules will be produced for each glucose molecule that is metabolized.

Here's how we get to this answer:

1. Under normal aerobic conditions, the complete oxidation of one glucose molecule through glycolysis, the Krebs cycle (also known as the citric acid cycle or TCA cycle), and the electron transport chain yields a total of about 36 or 38 ATPs (depending on the exact transport mechanism of NADH into the mitochondria, which can be variable in different organisms).

2. Glycolysis yields 2 ATPs per glucose molecule. However, the end product of glycolysis is pyruvate, which is then converted to acetyl-CoA if it enters the citric acid cycle.

3. If the antibiotic inhibits the synthesis of acetyl-CoA, then pyruvate cannot enter the Krebs cycle, and the cycles after glycolysis – the Krebs cycle and electron transport chain – are effectively halted.

4. The Krebs cycle and electron transport chain are responsible for the majority of ATP production during aerobic respiration. Specifically, a net gain of about 2 ATPs from the Krebs cycle and roughly 34 from the electron transport chain per glucose molecule (taking into account the variations in ATP yield), equaling 36 ATPs.

5. Without the production of acetyl-CoA and the functioning electron transport chain, the bacteria cells would be limited to the 2 ATP produced during glycolysis.

6. Therefore, without these systems functioning, each glucose molecule would produce 36 fewer ATPs (the 38 or so ATPs that could have been produced minus the 2 that were actually produced during glycolysis).