Chapter 8.3, Problem 1CSC

Raising a King

The mitochondrial DNA (mtDNA) that identified Richard III serves a unique role in the human body. Although the human nucleus has about 20,000 genes. mtDNA has only 37. Twenty-four of these code for RNA that helps translate genes into proteins, and the remaining 13 genes code for proteins that are subunits of enzymes that participate in the ETC and chemiosmosis. Some contribute to the ETC enzymes that cause NADH and FADH₂ to release their high-energy electrons into the chain. Other mtDNA genes help to produce the final enzyme in the chain, which combines the energy-depleted electrons with oxygen, forming water. Some genes in mtDNA code for parts of the ATP synthase enzyme on the inner mitochondrial membrane. If mtDNA were to disappear, cellular respiration would come to a screeching halt!

We’ve seen how NADH and FADH₂ can gain high-energy electrons that originated in glucose. Can these electron carriers also obtain high-energy electrons from other molecules in our diets, such as fat or protein?