Mitochondria are often called the "powerhouses" of the cell because they help make energy. They do this through a process known as cellular respiration, which happens in three main steps:

1. Glycolysis:

   • This step occurs in the cytoplasm, which is the jelly-like part of the cell, not inside the mitochondria.
   • In glycolysis, one glucose molecule (which is a type of sugar) is split into two smaller molecules called pyruvate.
   • This process gives us a net gain of 2 ATP (which is a form of energy that cells use) and some NADH (another energy carrier).

2. Krebs Cycle (Citric Acid Cycle):

   • This step happens inside the mitochondria.
   • Each pyruvate is changed into something called acetyl-CoA, which then goes into the Krebs cycle.
   • Each time the cycle runs, it makes 1 ATP, 3 NADH, and 1 FADH₂ (another energy carrier).
   • If both pyruvate molecules are processed, we get a total of 2 ATP from this step for each glucose molecule.

3. Electron Transport Chain (ETC):

   • This step takes place in the inner membrane of the mitochondria.
   • Here, electrons from NADH and FADH₂ move through a series of proteins, which helps pump protons (H⁺) into a space between the membranes.
   • This creates a difference in charge that powers an enzyme called ATP synthase, which can produce up to 34 ATP from one glucose molecule.

When we sum it all up, cellular respiration can create about 36-38 ATP molecules from just one glucose molecule. This shows how important mitochondria are for producing energy in our cells.