EVERYDAY SCIENCE

Detailed explanation-1: -When oxygen is not present or if an organism is not able to undergo aerobic respiration, pyruvate will undergo a process called fermentation. Fermentation does not require oxygen and is therefore anaerobic. Fermentation will replenish NAD+ from the NADH + H+ produced in glycolysis.

Detailed explanation-2: -Anaerobic respiration is useful in generating electricity in microbial fuel cells, which employ bacteria that respire solid electron acceptors (such as oxidized iron) to transfer electrons from reduced compounds to an electrode. This process can simultaneously degrade organic carbon waste and generate electricity.

Detailed explanation-3: -Both of these methods are called anaerobic cellular respiration. They do not require oxygen to achieve NAD+ regeneration and enable organisms to convert energy for their use in the absence of oxygen.

Detailed explanation-4: -Anaerobic glycolysis serves as a means of energy production in cells that cannot produce adequate energy through oxidative phosphorylation. In poorly oxygenated tissue, glycolysis produces 2 ATP by shunting pyruvate away from mitochondria and through the lactate dehydrogenase reaction.

Detailed explanation-5: -When sufficient oxygen is not present in the muscle cells for further oxidation of pyruvate and NADH produced in glycolysis, NAD+ is regenerated from NADH by reduction of pyruvate to lactate. Lactate is converted to pyruvate by the enzyme lactate dehydrogenase.