Lactobacilli lack electron transport chain. However, under special circumstances, up to 50% of ATP is synthesized by membrane-linked H+ - ATPase. What are the circumstances to generate a proton gradient to drive ATP formation mechanism.?
- If the concentration of lactic acid is higher in the cell than it is in the medium.
- If the concentration of lactic acid is lower in the cell than it is in the medium.
- Uniport (unidirectional)of lactic acid.
- Symport (both in or both out) of lactic acid with H+.
- Antiport (one in and one out) of lactic acid with H+.
I think options 2 and 4 should go together. H+ has to come inside the cell for ATP to be made inside the cell and if Lactic acid goes opposite way, there will be imbalance of charge.