Intermembrane space

[citation needed] The IMS of mitochondria plays a crucial role in coordinating a variety of cellular activities, such as regulation of respiration and metabolic functions.

[3] The IMS also contains many enzymes that use the ATP moving out of the matrix to phosphorylate other nucleotides and proteins that initiate apoptosis.

[7] Then they are transported across the inner mitochondrial membrane into the matrix and converted into the acetyl CoA to enter the citric acid cycle.

[4] Releasing of cytochrome c from the IMS to the cytosol activates procaspases and triggers a caspase cascade leading to apoptosis.

The eukaryotic Hsp70, which is the heat shock protein of 70 kDa, typically localized in the cytoplasm is also found in the IMS of chloroplasts.

The resulting hypothesis states that co-localization of Hsp70 is important for efficient translocation of protein precursors into and across the IMS of chloroplasts.