Final answer:
The cristae are partial partitions in a mitochondrion, formed by the infoldings of the inner membrane, which increase the surface area for cellular respiration and ATP synthesis.
Step-by-step explanation:
The partial partitions in a mitochondrion formed by infoldings of the inner membrane are known as cristae. These structures serve to increase the surface area of the inner membrane, which is crucial for ATP synthesis during cellular respiration. The inner membrane is a phospholipid bilayer with embedded proteins and distinguishes itself from the outer membrane by these extensive folds. Within the inner membrane is the mitochondrial matrix, which houses mitochondrial DNA, 70S ribosomes, and metabolic enzymes, replicating the conditions similar to that of a bacterial cytoplasm. Therefore, the cristae are not only structural features but also functional components essential for the mitochondrion's primary role in energy production.
Mitochondria, as observed through a transmission electron microscope, display the distinct two-membrane organization. The enveloping outer membrane and the highly folded inner membrane encapsulate the intermembrane space and the mitochondrial matrix, respectively. It's on the cristae where the electron transport chain operates and where the majority of ATP is generated.