Ultimately, respiration and fermentation are simply different ways to conclude sugar catabolism. following the energy-yielding reactions, respiring cells pass electrons to oxygen (or other external inorganic oxidant), while fermenting cells dump electrons back onto a partially oxidized organic molecule (such as pyruvate), which then exits the cell as a waste product. either way, the goal is to do which of the following?
a. fully oxidize nadh into co2 and h2o
b. recycle nadh back to nad+
c. generate as much nadh as possible (then synthesize more nad+ if necessary)
d. break down nadh into biosynthetic precursors
e. stimulate de novo production of nad+
recycle nadh back to nad+