How many molecules of ATP are generated during one turn of the Krebs cycle?

During one turn of the Krebs cycle, also known as the citric acid cycle or TCA cycle, one molecule of ATP is generated directly. This occurs through a substrate-level phosphorylation step where a high-energy molecule is converted into ATP.

It's important to note that the total energy yield from one turn of the Krebs cycle is higher when considering the electron carriers produced during the cycle. One turn results in the formation of three molecules of NADH and one molecule of FADH2. These carriers will later enter the electron transport chain, leading to the production of additional ATP through oxidative phosphorylation. However, specifically focusing on direct ATP production from one cycle, a single ATP molecule is produced.

This understanding clarifies the pivotal role of the Krebs cycle in cellular respiration, highlighting how it connects to both direct ATP generation and the broader context of energy production within the cell.