how big is a small is a mitochondria
Mitochondria can vary greately in both size (0.5 micrometers - 10 micrometers) and number (1 - over 1000) per cell. However, regardless of their size, number per cell , plant or animal origin, they have vary similar structures. 1  They are double membrane structures: having an inner membrane and an outer membrane. 2  There is a space between the inner and outer membranes called the intermembrane space.