Write a note on mitochondria

Mitochondria are double-membrane organelles that act as the powerhouse of the cell by producing energy in the form of ATP.

Mitochondria are found in almost all eukaryotic cells. They have an outer membrane and an inner membrane folded into cristae, which increase the surface area for energy production. Inside is the matrix, which contains enzymes, DNA, and ribosomes. 

Mitochondria generate ATP through aerobic respiration using glucose and oxygen. They also play roles in apoptosis (programmed cell death), heat production, and regulation of metabolic activities. Since they contain their own DNA, they can replicate independently, which supports the endosymbiotic theory.