Pyruvic acid is the end product of glycolysis. What are the three metabolic fates of pyruvic acid under aerobic and anaerobic conditions? Write them in the space provided in the diagram.

(N/A) The three metabolic fates of pyruvic acid are:
$(a)$ Lactic acid: Formed during anaerobic respiration in animal muscle cells (e.g., striated muscles) when oxygen is limited.
$(b)$ Ethanol and $CO_2$: Formed during anaerobic respiration (fermentation) in microorganisms like yeast.
$(c)$ Acetyl $CoA$: Formed during aerobic respiration in the mitochondria, which then enters the Krebs cycle.
The conversion of pyruvic acid to Acetyl $CoA$ is represented by the reaction:
Pyruvic acid $+ CoA + NAD^+ \xrightarrow{Mg^{+2}, \text{Pyruvate dehydrogenase}} \text{Acetyl } CoA + CO_2 + NADH + H^+$