Question

The figure below shows the structure of a mitochondrion with its four parts labelled A. B, C and D. Select the part correctly matched with its function.

• A. D (outer membrane) - gives rise to inner membrane by splitting.
• B. B (inner membrane)-forms infoldings called cristae.
• C. C (crista) - possesses single circular DNA molecule and ribosomes.
• D. A (matrix) - major site for respiratory chain enzymes.

Answer 1

Answer: (B)

Each mitochondrion is a double membrane- bound structure with the outer membrane and the inner membrane dividing its lumen distinctly into two aqueous compartments, i.e., the outer compartment and the inner compartment. The inner compartment is called the matrix. The outer membrane forms the continuous limiting boundary of the organelle. The inner membrane forms a number of infoldings called the cristae towards the matrix. The cristae increase the surface area. The two membranes have their own specific enzymes associated with the mitochondrial function.