Where is succinate dehydrogenase embedded in the mitochondrion?

Succinate dehydrogenase is indeed embedded in the inner mitochondrial membrane. This enzyme plays a crucial role in the citric acid cycle (also known as the Krebs cycle) as it catalyzes the conversion of succinate to fumarate, facilitating the removal of electrons from succinate. The inner mitochondrial membrane is where several key processes occur, including the electron transport chain, which is closely associated with succinate dehydrogenase due to its role in linking the citric acid cycle to the oxidative phosphorylation process.

The positioning of succinate dehydrogenase in the inner membrane allows it to participate in both the citric acid cycle and the electron transport chain. Specifically, the enzyme is unique among the citric acid cycle enzymes because it is directly involved in the membrane, allowing it to transfer electrons directly to electron carriers in the electron transport chain, which are also located in this membrane. This localization is essential for efficient energy production in aerobic respiration.

In contrast, the outer mitochondrial membrane, the matrix, and the intermembrane space do not have the same functional association with succinate dehydrogenase. The outer membrane mainly serves as a barrier and contains porins for transport, while the matrix is where other citric acid cycle reactions occur