Fig. 4.

Simple mitochondrial cristae model in 3D. An intermyofibrillar mitochondrion (IFM) of size 1500 nm × 300 nm × 300 nm. A. Top view, cross-section, mid-plane. B. End view cross-section mid-plane. Each crista in the model is 240 nm long × 20 nm square and separated from other cristae by 20 nm. There are 42 cristae in a 40 nm plane and 7 layers of cristae, for a total of 294 cristae. The surface area per crista is 240 nm × 20 nm × 4 + 20 × 20 nm² or 1.96 10⁴ nm². Thus the surface area of the inner membrane is 1.96 10⁴ × 294 or 5.76 10⁶ nm², which is about three times larger than the surface area of the outer member, 1.98 10⁶ nm². The matrix is approximately half of the volume contained within the outer membrane. As noted, other shapes of the cristae may occur and will affect mitochondrial function.