Draw the structure of mitochondria.

Mitochondria are double-membrane-bound organelles with a distinctive structure optimized for energy production. The outer membrane is smooth and permeable to small molecules, forming the organelle's exterior boundary and separating it from the cytoplasm. The inner membrane is extensively folded into finger-like projections called cristae, which dramatically increase the surface area available for ATP synthesis. This inner membrane is selectively permeable and contains the electron transport chain proteins and ATP synthase enzymes responsible for oxidative phosphorylation. The space between the outer and inner membranes is called the intermembrane space.

The innermost compartment, enclosed by the inner membrane, is called the mitochondrial matrix. This gel-like substance contains enzymes for the Krebs cycle (citric acid cycle), mitochondrial DNA (a circular chromosome similar to bacterial DNA, supporting the endosymbiotic theory of mitochondrial origin), mitochondrial ribosomes (70S type, smaller than cytoplasmic ribosomes), and various proteins involved in energy metabolism. The cristae provide the enormous surface area needed to house thousands of copies of the ATP-producing machinery, while the matrix houses the enzymatic pathways that prepare molecules for final energy extraction. This compartmentalized structure allows mitochondria to create a proton gradient across the inner membrane, which drives ATP synthesis—the cell can produce approximately 36-38 ATP molecules from one glucose molecule through this efficient design.