What metabolism take place during lack of electron acceptors

Question

Problem:

Question 1: What metabolism would be favored when there is a lack of electron acceptors?

1. anoxygenic photosynthesis
2. acetogenesis
3. anaerobic fermentation
4. anoxic ammonia oxidation

 

Question 2: What would likely occur if an anammox bacterium was unable to use ladderane lipids?

1. Rates of anammox would be considerably slower due to a lack of localized metabolism.
2. Reactive nitrogen species would kill the cell.
3. It would require a different source for carbon assimilation.
4. Ammonium rather than ammonia would be used due to ammonia toxicity to other cellular processes.

Please select correct answer and also provide explaination.