What energy-carrying molecules are primarily produced during the Citric Acid Cycle?

During the Citric Acid Cycle, the primary energy-carrying molecules produced are NADH and FADH2. This cycle, also known as the Krebs Cycle or TCA Cycle, takes place in the mitochondria and plays a crucial role in cellular respiration by oxidizing acetyl-CoA.

As the cycle progresses through a series of enzymatic reactions, several key transformations occur, including the conversion of isocitrate to alpha-ketoglutarate and subsequently to succinyl-CoA. These steps involve the reduction of NAD+ to NADH, which captures high-energy electrons. Similarly, at a later stage, the conversion of succinate to fumarate leads to the reduction of FAD to FADH2, another important energy carrier.

NADH and FADH2 are vital because they store energy that can be utilized in the electron transport chain, where their electrons are ultimately transferred to produce ATP, the primary energy currency of the cell. Understanding the production of these molecules is critical for grasping how the Citric Acid Cycle contributes to the overall process of energy metabolism in aerobic organisms.