Question

Most of the biological energy is supplied by mitochondria through

• A. Breaking of proteins
• B. Reduction of $NAD{P}^{+}$
• C. Breaking of sugars
• D. Oxidising TCA substrates

Answer 1

Answer: (D)

Oxidising TCA substrates

Mitochondrial matrix houses the entire process of Krebs' cycle except succinyl dehydrogenase enzyme which is located in the inner membrane of mitochondria. Krebs' cycle or TCA cycle is a catabolic oxidation of organic substrates which results in release of CO2 and H2O. As it entirely occurs in mitochondria, primary supply of energy by mitochondria is through the TCA cycle.

So the answer is 'Oxidising TCA substrates'.