The inner membrane is a membrane (phospholipid bilayer) of an organelle that is within the outer membrane. The inner membrane is present within the mitochondria and the chloroplast of cells.

Mitochondrial Inner Membrane

The mitochondrial inner membrane forms internal compartments known as cristae, which allow greater room for the proteins (cytochromes) to function properly and efficiently. The electron transport chain is located on the inner membrane of the mitochondria. Within the inner mitochondrial membrane are also transport proteins that transport in a highly controlled manner metabolites across this membrane.

Inner Membrane of Chloroplast

The inner membrane of the chloroplast surrounds the stroma of the chloroplast. Within the stroma are the thylakoids.

See also

• Intermembrane space
• Chloroplast membrane

Membrane biology