What do mitochondria do?

• A. Produce energy (ATP)
• B. Store DNA
• C. Synthesize lipids
• D. Detoxify chemicals

Answer: (A)

Mitochondria are the cell’s powerhouses, turning the energy from nutrients into ATP, the molecule cells use for work. Through cellular respiration, nutrients are broken down in a sequence: glycolysis in the cytoplasm provides pyruvate, which enters the mitochondrion and becomes acetyl-CoA; the citric acid cycle extracts energy-rich electrons; and the electron transport chain uses those electrons to pump protons across the inner membrane, with ATP synthase then making ATP from ADP. This ATP powers nearly every energy-rerequiring process in the cell, from muscle contraction to active transport and biosynthesis. Mitochondria also contain some of their own DNA and ribosomes, reflecting their evolutionary origin, but their central role is energy production. Other tasks like storing DNA, synthesizing lipids, or detoxifying chemicals are handled by other organelles such as the nucleus, smooth endoplasmic reticulum, and peroxisomes.