What two distinct stages are involved in the energy generation process?

Glycolysis (Stage 1):

- Takes place in the cytoplasm

- Breaks down glucose (6-carbon sugar) into two molecules of pyruvate (3-carbon compound)

- Generates a small amount of ATP (net gain of 2 ATP) and NADH (reduced form of nicotinamide adenine dinucleotide)

Krebs Cycle (Citric Acid Cycle, Stage 2):

- Occurs in the mitochondrial matrix

- Pyruvate from glycolysis enters the cycle

- Series of chemical reactions lead to the release of CO2 and the generation of ATP, NADH, and FADH2 (flavin adenine dinucleotide)