Liver
In humans, under ANAEROBIC conditions (no O2), pyruvate is 'converted' to lactate, though I wouldn't say it is "broken down".In humans, under AEROBIC conditions (O2 present), pyruvate is converted to Acetyl-CoA, via the pyruvate dehydrogenase reaction.In yeast, pyruvate is converted into ethanol (Party Fluid) via pyruvate decarboxylase and then alcohol dehydrogenase.
fermentation
It is converted to acetaldehyde and then further broken down in the liver.
lactc acid
carbohydrates
oxygen
It can be converted to water and carbon dioxide by setting it on fire. Ethanol can be broken down in the body by an enzyme called alcohol dehydrogenase.
Lactate
Anaerobic cellular respiration breaks down glucose into lactate
amino acids are, broken down / converted, to urea
Energy. Carbohydrates are broken down into glucose, which will be converted to ATP, NADH and FADH2 by enzymes.
In human body,H2O2 is broken down intn water.Enzyme involved is catalase.