Mitochondria are cellular organelles that are in charge of oxidative phosphorylation, which is the critical process of turning nutrients into adenosine triphosphate (ATP) molecules that power normal cell operations. At least hundreds of mitochondria are found in each neuron. Because nerve cells are postmitotic, any mitochondrial damage received will accumulate over time and produce malfunction. Cells die as a result of widespread mitochondrial damage because they can no longer create adequate energy.
Galaxy is a collection of stars, gas, and dust bound together by gravity. The smallest galaxies may contain only a few hundred thousand stars, while the largest galaxies have thousands of billions of stars.
