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+

B. recycle NADH back to NAD+

Explanation:

Both respiration and fermentation share a common pathway, that is glycolysis. The redox reactions of glycolysis use NAD+ as an electron acceptor and NADH is formed. To continue the process of respiration and fermentation, oxidation of NADH into NAD+ is required so that NAD+ can serve as an electron acceptor for glycolytic reactions.

Aerobic respiration oxidizes NADH into NAD+ by transferring its electrons to the terminal electron acceptor, the molecular oxygen. On the other hand, fermentation oxidizes NADH through the formation of lactic acid or ethanol from pyruvate.

answer: all : )

explanation:

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!