Question

Most TCA cycle enzymes of eukaryotic cells are nuclear encoded and are synthesized in the cytosol as inactive precursors (translated from corresponding mRNAs on free cytosolic ribosomes). How do these inactive precursor proteins end up as active TCA cycle enzymes in the mito matrix?

Answer 1

Inactive precursor proteins synthesized in the cytosol are transported into the inner mitochondrial matrix where they are metabolized by enzymes in the Krebs cycle (TCA cycle) to produce high-energy molecules.

Step-by-step explanation:

Most TCA cycle enzymes of eukaryotic cells are nuclear encoded and are synthesized in the cytosol as inactive precursors, translated from corresponding mRNAs on free cytosolic ribosomes. These inactive precursor proteins are then transported into the inner mitochondrial matrix, where they are metabolized by enzymes in a pathway called the Krebs cycle or TCA cycle. This cycle takes place in the matrix of mitochondria and involves a series of redox, dehydration, hydration, and decarboxylation reactions that produce high-energy molecules, including ATP, NADH, and FADH2. The NADH and FADH2 produced in the Krebs cycle are then used in the electron transport chain in the mitochondria to generate more ATP molecules.