Anatomy of the Heart. Your heart is located under your ribcage in the center of your chest between your right and left lungs. Its muscular walls beat, or contract, pumping blood to all parts of your body. The size of your heart can vary depending on your age, size, and the condition of your heart.
In anaerobic respiration, NADH loses its electrons to other molecules in the process of fermentation for the purpose of regenerating the NAD+ needed to continue oxidizing organic molecules to produce ATP by substrate-level phosphorylation.
More specifically, the differences in aerobic and anaerobic respiration rest on the different very roles played by the NADH molecule produced in step 5 of glycolysis. In both aerobic and anaerobic respiration, the NADH molecule is part of the enzyme complex and must be restored to its NAD, oxidized state.