Crista

In biology, a crista (plural: cristae) is a fold in the inner membrane of a mitochondrion. Mitochondria are organelles found in eukaryotic cells, responsible for generating most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy.

The cristae significantly increase the surface area of the inner mitochondrial membrane, allowing for a greater density of electron transport chain proteins and ATP synthase. These proteins are crucial for oxidative phosphorylation, the process by which ATP is produced.

The shape and number of cristae can vary depending on the tissue type and metabolic activity of the cell. Cells with high energy demands, such as muscle cells, tend to have more cristae than cells with lower energy demands.

The structure of cristae is maintained by a protein complex known as the mitochondrial contact site and cristae organizing system (MICOS). MICOS helps to tether the cristae to the inner boundary membrane of the mitochondrion and ensures their proper morphology. Disruption of MICOS can lead to cristae disorganization and mitochondrial dysfunction.