Question

You add a drug that oxidizes NADH to NAD+ IMMEDIATELY after it is produced in the Krebs Cycle.   What would happen to the production of ATP by chemiosmosis. Explain your reasoning

Answer 1

In presence of such drug, amount of ATP synthsized by chemiosmosis will be decreased.

Explanation

As we know that All the NADH and FADH2 after production enter in to ETC . In ETC, NADH enter at level of complex I and FADH2 enter at complex II. They transfer there electron to these complexes respectively. As these electron move in to ETC, at some complexs ( complex I, complex III and complex IV) much energy is released which is used to transport H+ in to intermembrane space

. This creates a pH difference between matrix ( more baic) and intermembrane space ( more acidic). And lead to generation of proton motive force ( PMV) . This PMV is responsible for formation of ATP using complex V.

As during catabolism of food , much of the energy released in form of NADH , if added drug immediately convert NADH to NAD . Then there will less entry of NADH in to ETC , less transport of protons in to intermembrane space, less generation of PMF and , less ATP generation.