Mitochondrienmembran

Mitochondrienmembran refers to the membranes that enclose a mitochondrion, an organelle found in eukaryotic cells. Mitochondria are often referred to as the "powerhouses of the cell" because they are responsible for generating most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy. A mitochondrion is delimited by two distinct membranes: the outer mitochondrial membrane and the inner mitochondrial membrane. These membranes are composed of a lipid bilayer and embedded proteins, similar to the plasma membrane of the cell.

The outer mitochondrial membrane is relatively permeable to small molecules and ions, acting as a barrier between the cytoplasm and the mitochondrial matrix. It contains porins, which are channel-forming proteins that allow passage of molecules up to about 5000 daltons. The inner mitochondrial membrane, on the other hand, is highly impermeable to most molecules and ions, except for specific transport proteins. This impermeability is crucial for maintaining the proton gradient required for ATP synthesis. The inner mitochondrial membrane is folded into cristae, which greatly increase its surface area, providing more space for the electron transport chain and ATP synthase complexes, the key machinery for oxidative phosphorylation. The space between the outer and inner membranes is called the intermembrane space.