Why is fermentation such an important process in cells?

Because Glycolysis, juts like Cellular Respiration, needs a molecules that picks up electrons. Glycolysis needs molecules of NAD+. 

Hello there,
Fermentation does not make energy but it makes CO2 and it starts with glucose, goes through glycolysis and gets pyruvates. Fermentation allows glycolysis to continue. It also allows glycosis to occur without oxygen

Hope this helps :))

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That is true tge cactus as a structural adaptation to its envirinment has it leaves reduced to spines. but this doesnt mean it cant produce food it produces food because of the presence of chlorophyll in its stem