EVERYDAY SCIENCE

Detailed explanation-1: -Fate of pyruvate: The fate of pyruvate depends on the availability of oxygen. If oxygen is available: If oxygen is available, pyruvate is transported to mitochondria. Inside the mitochondria, pyruvate undergoes oxidative decarboxylation and produces acetyl CoA.

Detailed explanation-2: -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-3: -Aerobic respiration: Pyruvate is oxidatively decarboxylated into Acetyl CoA which further moves into the Krebs cycle. Lactic acid fermentation: Pyruvate reacts with the Lactate dehydrogenase enzyme to produce Lactic Acid and molecules of ATP.

Detailed explanation-4: -In lactate fermentation, pyruvate is converted to lactate by the enzyme lactate dehydrogenase. In the process, NAD+ is regenerated. The reaction catalyzed by lactate dehydrogenase (LDH) is shown in Figure 13.2. 2.

Detailed explanation-5: -In the absence of oxygen, pyruvate is converted to lactate, and NADH is reoxidized to NAD+. In the presence of oxygen, pyruvate is converted to acetyl-CoA and then enters the citric acid cycle. More ATP can be formed from the breakdown of glucose when oxygen is present.