Iron is considered an essential element for many bacteria. Based on the animation, how would lack of iron affect energy production of a bacterium?
1) Lack of iron would mean that most of the oxygen could be reduced to form water, improving energy yields.
2) Lack of iron would mean lack of heme, and thus lower amounts of functioning cytochrome proteins. This would mean lower energy yields.
3) Lack of iron would not have any affect on this system.