Which of the following processes occurs in mitochondria?

The Krebs cycle, also known as the citric acid cycle or tricarboxylic acid (TCA) cycle, occurs within the mitochondria of eukaryotic cells. This cycle is a crucial part of cellular respiration, which is the process that cells use to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and it plays a key role in the aerobic metabolism of glucose and other compounds.

In the mitochondria, pyruvate produced from glycolysis in the cytoplasm is converted into acetyl-CoA, which then enters the Krebs cycle. Throughout this cycle, a series of chemical reactions take place, leading to the release of carbon dioxide and the production of energy-rich molecules such as NADH and FADH2. These molecules are essential for the electron transport chain, which generates the majority of ATP in aerobic respiration.

In contrast, the light-dependent reactions occur in the chloroplasts of plant cells, glycolysis takes place in the cytoplasm, and the Calvin cycle also occurs in chloroplasts. Therefore, the Krebs cycle's location in the mitochondria is what distinguishes it as the correct answer to this question.