CBSE Class 9 Answered
Mitochondria are the power centers of the cell. They are about the size of bacteria but may have different shapes depending on the cell type.
Mitochondria are membrane-bound organelles, and like the nucleus have a double membrane. They have their own independent genome. Both outer and inner membranes composed of phospholipid bilayers and proteins. There is present an intermembrane space between the outer membrane and the inner membrane. The outer membrane is fairly smooth. But the inner membrane is highly convoluted, forming folds called cristae. The cristae greatly increase the inner membrane's surface area. They are studded with proteins, including ATP synthase and a variety of cytochromes. The matrix is the space enclosed by the inner membrane. The matrix contains mitochondrial DNA, tRNA, ribosomes and enzymes. Krebs cycle occurs in the matrix.