This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory chain, Subject name: Biochemistry
The power house of the cell is 
Select and explain. 
A. Nucleus, B. Cell membrane, C. Mitochondria, D. Lysosomes
C: Mitochondria
Answer: C: Mitochondria 
Explanation: Aerobic organisms are able to capture a far greater propoion of the available free energy of respiratory substrates than anaerobic organisms. Most of this takes place inside mitochondria, which have been termed the "powerhouses" of the cell. Respiration is coupled to the generation of the high-energy intermediate, ATP, by oxidative phosphorylation.Ref: Harper&;s Biochemistry; 30th edition; Chapter 13; The Respiratory Chain & Oxidative Phosphorylation