You have just discovered a new antibiotic This antibiotic is

You have just discovered a new antibiotic. This antibiotic is a small organic molecule that dissolves in a cytoplasmic membrane then \"ferries\" protons (H+) back and forth across the membrane. The antibiotic releases the H+\'s on whichever side of the membrane the concentration is lower, until ultimately the proton concentration across the membrane reaches equilibrium. When this antibiotic is added to a culture of aerobically respiring bacteria, which of the following processes will be stopped virtually immediately: electron transfer reactions from NADH to flavoprotein to non-heme iron protein, etc.? the Kreb\'s (or TCA) cycle? utilization of oxygen? ATP synthesis by substrate-level phosphorylation? ATP synthesis by oxidative phosphorylation? motility? Which type of bacterium. Lactobacillus or Pseudomonas, would suffer the effects from the antibiotic most quickly? Explain.

Solution

A. The antibiotic dissolved in the membrane, and allows the H+ ions from high concentration gradiant to low concentration gradient. Here this antibiotic acting as a channel or uncoupler and decreases the proton gradient with out synthesis of ATP. As uncouplers does not affect electron transport chain, oxygen utilization, substrate level phosphorylation. But only affect ATP synthesis and consequently flagellar moment that leads to motility. sO THE ANSWERS ARE V & VI

B. Pseudomonas bacteria most quickly suffer . As Pseudomonas is an aerobic bacteria, where electron transport occur, proton pumping occurs. Proton pumping is discharged by the antibiotic without synthesis of ATP. As lactobacillus not purely depends on electron transport, proton pumping, it never affect by antibiotic.,